Stavzor

• Bipolar Disorder
• Migraine Headache
• Seizure (Epilepsy)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of valproic acid in children. However, safety and efficacy have not been established in children with epilepsy younger than 10 years of age, and in children with migraine younger than 12 years of age. Because of valproic acid's toxicity, use in children younger than 2 years of age requires extreme caution.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of valproic acid in the elderly. However, elderly patients are more likely to have unwanted effects (eg, tremors or unusual drowsiness), which may require an adjustment in the dose for patients receiving valproic acid.

Pregnancy

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Calcifediol
• Cisplatin
• Doripenem
• Ertapenem
• Estradiol
• Ethinyl Estradiol
• Imipenem
• Lamotrigine
• Meropenem
• Mestranol
• Orlistat
• Primidone
• Propofol
• Sodium Oxybate
• Vorinostat
• Warfarin

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acyclovir
• Aspirin
• Betamipron
• Carbamazepine
• Cholestyramine
• Clomipramine
• Erythromycin
• Ethosuximide
• Felbamate
• Fosphenytoin
• Ginkgo
• Lopinavir
• Lorazepam
• Mefloquine
• Nimodipine
• Nortriptyline
• Olanzapine
• Oxcarbazepine
• Panipenem
• Phenobarbital
• Phenytoin
• Rifampin
• Rifapentine
• Risperidone
• Ritonavir
• Rufinamide
• Topiramate
• Valacyclovir
• Zidovudine

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Congenital metabolism disorders (born with a disease that affects metabolism) or
• Mental retardation with severe seizure disorders—Use with caution. May increase risk for more serious side effects.

• Depression, or history of or
• Mental illness, or history of or
• Pancreatitis (inflammation of the pancreas) or
• Thrombocytopenia (low platelet count)—Use with caution. May make these conditions worse.

• Liver disease or
• Mitochondrial disorder, including Alpers-Huttenlocher syndrome (genetic disorder) or
• Urea cycle disorder (genetic disorder)—Should not be used in patients with these conditions.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

• Stavzor should not be administered to patients with hepatic disease or significant hepatic dysfunction [see Warnings and Precautions (5.1)].
• Stavzor is contraindicated in patients known to have mitochondrial disorders caused by mutations in mitochondrial DNA polymerase γ (POLG; e.g., Alpers-Huttenlocher Syndrome) and children under two years of age who are suspected of having a POLG-related disorder [see Warnings and Precautions (5.1)].
• Stavzor is contraindicated in patients with known hypersensitivity to the drug [see Warnings and Precautions (5.11)].
• Stavzor is contraindicated in patients with known urea cycle disorders [see Warnings and Precautions (5.5)].
• Stavzor is contraindicated for use in prophylaxis of migraine headaches in pregnant women [see Warnings and Precautions (5.3) and Use in Specific Populations (8.1)].

Hepatotoxicity

General Information on Hepatotoxicity

Hepatic failure resulting in fatalities has occurred in patients receiving valproate These incidents usually have occurred during the first six months of treatment. Serious or fatal hepatotoxicity may be preceded by non-specific symptoms such as malaise, weakness, lethargy, facial edema, anorexia, and vomiting. In patients with epilepsy, a loss of seizure control may also occur. Patients should be monitored closely for appearance of these symptoms. Serum liver function tests should be performed prior to therapy and at frequent intervals thereafter, especially during the first sixmonths. However, healthcare providers should not rely totally on serum biochemistry since these tests may not be abnormal in all instances, but should also consider the results of careful interim medical history and physical examination.

Caution should be observed when administering valproate products to patients with a prior history of hepatic disease. Patients on multiple anticonvulsants, children, those with congenital metabolic disorders, those with severe seizure disorders accompanied by mental retardation, and those with organic brain disease may be at particular risk. See below, "Patients with known or suspected mitochondrial disease."

Experience has indicated that children under the age of two years are at a considerably increased risk of developing fatal hepatotoxicity, especially those with the aforementioned conditions. When Stavzor is used in this patient group, it should be used with extreme caution and as a sole agent. The benefits of therapy should be weighed against the risks. In progressively older patient groups experience in epilepsy has indicated that the incidence of fatal hepatotoxicity decreases considerably.

Patients with Known or Suspected Mitochondrial Disease

Valproate-induced acute liver failure and liver-related deaths have been reported in patients with hereditary neurometabolic syndromes caused by mutations in the gene for mitochondrial DNA polymerase γ (POLG) (e.g., Alpers-Huttenlocher Syndrome) at a higher rate than those without these syndromes. Most of the reported cases of liver failure in patients with these syndromes have been identified in children and adolescents.

POLG-related disorders should be suspected in patients with a family history or suggestive symptoms of a POLG-related disorder, including but not limited to unexplained encephalopathy, refractory epilepsy (focal, myoclonic), status epilepticus at presentation, developmental delays, psychomotor regression, axonal sensorimotor neuropathy, myopathy cerebellar ataxia, opthalmoplegia, or complicated migraine with occipital aura. POLG mutation testing should be performed in accordance with current clinical practice for the diagnostic evaluation of such disorders. The A467T and W748S mutations, are present in approximately 2/3 of patients with autosomal recessive POLG-related disorders. Stavzor is contraindicated in patients known to have mitochondrial disorders caused by POLG mutations and children under two years of age who are clinically suspected of having a mitochondrial disorder [see Contraindications (4)]. In patients over two years of age who are clinically suspected of having a hereditary mitochondrial disease, Stavzor should only be used after other anticonvulsants have failed. This older group of patients should be closely monitored during treatment with Stavzor for the development of acute liver injury with regular clinical assessments and serum liver test monitoring

The drug should be discontinued immediately in the presence of significant hepatic dysfunction, suspected or apparent. In some cases, hepatic dysfunction has progressed in spite of discontinuation of drug [see Boxed Warning and Contraindications (4)].

Birth Defects

Valproate can cause fetal harm when administered to a pregnant woman. Pregnancy registry data show that maternal valproate use can cause neural tube defects and other structural abnormalities (e.g., craniofacial defects, cardiovascular malformations and malformations involving various body systems). The rate of congenital malformations among babies born to mothers using valproate is about four times higher than the rate among babies born to epileptic mothers using other anti-seizure monotherapies. Evidence suggests that folic acid supplementation prior to conception and during the first trimester of pregnancy decreases the risk for congenital neural tube defects in the general population.

Decreased IQ following in utero exposure

Valproate can cause decreased IQ scores following in utero exposure. Published epidemiological studies have indicated that children exposed to valproate in utero have lower cognitive test scores than children exposed in utero to either another antiepileptic drug or to no antiepileptic drugs. The largest of these studies1 is a prospective cohort study conducted in the United States and United Kingdom that found that children with prenatal exposure to valproate (N=62) had lower IQ scores at age 6 (97 [95% C.I. 94-101]) than children with prenatal exposure to the other antiepileptic drug monotherapy treatments evaluated: lamotrigine (108 [95% C.I. 105–110]), carbamazepine (105 [95% C.I. 102–108]), and phenytoin (108 [95% C.I. 104–112]). Because the women in this study were exposed to antiepileptic drugs throughout pregnancy, whether the risk for decreased IQ was related to a particular time period during pregnancy could not be assessed. Although all of the available studies have methodological limitations, the weight of the evidence supports the conclusion that valproate exposure in utero causes decreased IQ in children.

In animal studies, offspring with prenatal exposure to valproate had malformations similar to those seen in humans and demonstrated neurobehavioral deficits [see Use in Specific Populations (8.1)].

Valproate use is contraindicated during pregnancy in women being treated for prophylaxis of migraine headaches. Women with epilepsy or bipolar disorder who are pregnant or who plan to become pregnant should not be treated with valproate unless other treatments have failed to provide adequate symptom control or are otherwise unacceptable. In such women, the benefits of treatment with valproate during pregnancy may still outweigh the risks.

Use in Women of Childbearing Potential

Because of the risk to the fetus of decreased IQ and major congenital malformations (including neural tube defects), which may occur very early in pregnancy, valproate should not be administered to a woman of childbearing potential unless the drug is essential to the management of her medical condition. This is especially important when valproate use is considered for a condition not usually associated with permanent injury or death (e.g., migraine). Women should use effective contraception while using valproate. Women who are planning a pregnancy should be counseled regarding the relative risks and benefits of valproate use during pregnancy, and alternative therapeutic options should be considered for these patients [see Boxed Warning and Use in Specific Populations (8.1)].

To prevent major seizures, valproate should not be discontinued abruptly, as this can precipitate status epilepticus with resulting maternal and fetal hypoxia and threat to life.

Evidence suggests that folic acid supplementation prior to conception and during the first trimester of pregnancy decreases the risk for congenital neural tube defects in the general population. It is not known whether the risk of neural tube defects or decreased IQ in the offspring of women receiving valproate is reduced by folic acid supplementation. Dietary folic acid supplementation both prior to conception and during pregnancy should be routinely recommended for patients receiving valproate.

Pancreatitis

Cases of life-threatening pancreatitis have been reported in both children and adults receiving valproate. Some of the cases have been described as hemorrhagic with rapid progression from initial symptoms to death. Some cases have occurred shortly after initial use as well as after several years of use. The rate based upon the reported cases exceeds that expected in the general population and there have been cases in which pancreatitis recurred after rechallenge with valproate. In clinical trials, there were 2 cases of pancreatitis without alternative etiology in 2416 patients, representing 1044 patient-years experience. Patients and guardians should be warned that abdominal pain, nausea, vomiting, and/or anorexia can be symptoms of pancreatitis that require prompt medical evaluation. If pancreatitis is diagnosed, Stavzor should ordinarily be discontinued. Alternative treatment for the underlying medical condition should be initiated as clinically indicated [see Boxed Warning].

Urea Cycle Disorders

Stavzor is contraindicated in patients with known urea cycle disorders (UCD). Hyperammonemic encephalopathy, sometimes fatal, has been reported following initiation of valproate therapy in patients with UCD, a group of uncommon genetic abnormalities, particularly ornithine transcarbamylase deficiency. Prior to the initiation of Stavzor therapy, evaluation for UCD should be considered in the following patients: 1) those with a history of unexplained encephalopathy or coma, encephalopathy associated with a protein load, pregnancy-related or postpartum encephalopathy, unexplained mental retardation, or history of elevated plasma ammonia or glutamine; 2) those with cyclical vomiting and lethargy, episodic extreme irritability, ataxia, low blood urea nitrogen (BUN), or protein avoidance; 3) those with a family history of UCD or a family history of unexplained infant deaths (particularly males); 4) those with other signs or symptoms of UCD. Patients who develop symptoms of unexplained hyperammonemic encephalopathy while receiving valproate therapy should receive prompt treatment (including discontinuation of valproate therapy) and be evaluated for underlying UCD [see Contraindications (4) and Warnings and Precautions (5.8),(5.9)].

Suicidal Behavior and Ideation

Antiepileptic drugs (AEDs), including Stavzor, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior.

Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide.

The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed.

The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5-100 years) in the clinical trials analyzed.

Table 1 shows absolute and relative risk by indication for all evaluated AEDs.

The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications.

Anyone considering prescribing Stavzor or any other AED must balance the risk of suicidal thoughts and behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.

Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm. Behaviors of concern should be reported immediately to healthcare providers.

Thrombocytopenia

The frequency of adverse effects (particularly elevated liver enzymes and thrombocytopenia) may be dose related. In a clinical trial of valproate as monotherapy in patients with epilepsy, 34/126 patients (27%) receiving approximately 50 mg/kg/day on average, had at least one value of platelets ≤75 × 109/L. Approximately half of these patients had treatment discontinued, with return of platelet counts to normal. In the remaining patients, platelet counts normalized with continued treatment. In this study, the probability of thrombocytopenia appeared to increase significantly at total valproate concentrations of ≥110 mcg/mL (females) or ≥135 mcg/mL (males). The therapeutic benefit which may accompany the higher doses should therefore be weighed against the possibility of a greater incidence of adverse effects.

Because of reports of thrombocytopenia, inhibition of the secondary phase of platelet aggregation, and abnormal coagulation parameters, (eg, low fibrinogen), platelet counts and coagulation tests are recommended before initiating therapy and at periodic intervals. It is recommended that patients receiving Stavzor be monitored for platelet count and coagulation parameters prior to planned surgery. In a clinical trial of valproate as monotherapy in patients with epilepsy, 34/126 patients (27%) receiving approximately 50 mg/kg/day on average, had at least one value of platelets ≤75 × 109/L. Approximately half of these patients had treatment discontinued, with return of platelet counts to normal. In the remaining patients, platelet counts normalized with continued treatment. In this study, the probability of thrombocytopenia appeared to increase significantly at total valproate concentrations of ≥110 mcg/mL (females) or ≥135 mcg/mL (males). Evidence of hemorrhage, bruising, or a disorder of hemostasis/coagulation is an indication for reduction of the dosage or withdrawal of therapy.

Hyperammonemia

Hyperammonemia has been reported in association with valproate therapy and may be present despite normal liver function tests. In patients who develop unexplained lethargy and vomiting or changes in mental status, hyperammonemic encephalopathy should be considered and an ammonia level should be measured. Hyperammonemia should also be considered in patients who present with hypothermia [see Warnings and Precautions (5.10)].

If ammonia is increased, valproate therapy should be discontinued. Appropriate interventions for treatment of hyperammonemia should be initiated, and such patients should undergo investigation for underlying urea cycle disorders [see Contraindications (4) and Warnings and Precautions (5.5)].

Asymptomatic elevations of ammonia are more common and when present, require close monitoring of plasma ammonia levels. If the elevation persists, discontinuation of valproate therapy should be considered.

Hyperammonemia and Encephalopathy Associated With Concomitant Topiramate Use

Concomitant administration of topiramate and valproic acid has been associated with hyperammonemia with or without encephalopathy in patients who have tolerated either drug alone. Clinical symptoms of hyperammonemic encephalopathy often include acute alterations in level of consciousness and/or cognitive function with lethargy or vomiting. Hypothermia can also be a manifestation of hyperammonemia [see Warnings and Precautions (5.10)].

In most cases, symptoms and signs abated with discontinuation of either drug. This adverse event is not due to a pharmacokinetic interaction. It is not known if topiramate monotherapy is associated with hyperammonemia. Patients with inborn errors of metabolism or reduced hepatic mitochondrial activity may be at an increased risk for hyperammonemia with or without encephalopathy. Although not studied, an interaction of topiramate and valproic acid may exacerbate existing defects or unmask deficiencies in susceptible persons. In patients who develop unexplained lethargy, vomiting, or changes in mental status, hyperammonemic encephalopathy should be considered and an ammonia level should be measured [see Contraindications (4) and Warnings and Precautions (5.8)].

Hypothermia

Hypothermia, defined as an unintentional drop in body core temperature to < 35° C (95° F), has been reported in association with valproate therapy both in conjunction with and in the absence of hyperammonemia. This adverse reaction can also occur in patients using concomitant topiramate with valproate after starting topiramate treatment or after increasing the daily dose of topiramate [see Drug Interactions (7.3)]. Consideration should be given to stopping valproate in patients who develop hypothermia, which may be manifested by a variety of clinical abnormalities including lethargy, confusion, coma, and significant alterations in other major organ systems such as the cardiovascular and respiratory systems. Clinical management and assessment should include examination of blood ammonia levels.

Multi-Organ Hypersensitivity Reactions

Multi-organ hypersensitivity reactions have been rarely reported in close temporal association to the initiation of valproate therapy in adult and pediatric patients (median time to detection 21 days: range 1 to 40 days). Although there have been a limited number of reports, many of these cases resulted in hospitalization and at least one death has been reported. Signs and symptoms of this disorder were diverse; however, patients typically, although not exclusively, presented with fever and rash associated with other organ system involvement. Other associated manifestations may include lymphadenopathy, hepatitis, liver function test abnormalities, hematological abnormalities (e.g., eosinophilia, thrombocytopenia, neutropenia), pruritus, nephritis, oliguria, hepatorenal syndrome, arthralgia, and asthenia. Because the disorder is variable in its expression, other organ system symptoms and signs, not noted here, may occur. If this reaction is suspected, valproate should be discontinued and an alternative treatment started. Although the existence of cross sensitivity with other drugs that produce this syndrome is unclear, the experience amongst drugs associated with multi-organ hypersensitivity would indicate this to be a possibility.

Interaction with Carbapenem Antibiotics

Carbapenem antibiotics (for example, ertapenem, imipenem, meropenem; this is not a complete list) may reduce serum valproic acid concentrations to subtherapeutic levels, resulting in loss of seizure control. Serum valproic acid concentrations should be monitored frequently after initiating carbapenem therapy. Alternative antibacterial or anticonvulsant therapy should be considered if serum valproic acid concentrations drop significantly or seizure control deteriorates [see Drug Interactions (7.1)].

Somnolence in the Elderly

In a double-blind, multicenter trial of valproate in elderly patients with dementia (mean age = 83 years), doses were increased by 125 mg/day to a target dose of 20 mg/kg/day. A significantly higher proportion of valproate patients had somnolence compared to placebo, and although not statistically significant, there was a higher proportion of patients with dehydration. Discontinuations for somnolence were also significantly higher than with placebo. In some patients with somnolence (approximately one-half), there was associated reduced nutritional intake and weight loss. There was a trend for the patients who experienced these events to have a lower baseline albumin concentration, lower valproate clearance, and a higher BUN. In elderly patients, dosage should be increased more slowly and with regular monitoring for fluid and nutritional intake, dehydration, somnolence, and other adverse reactions. Dose reductions or discontinuation of valproate should be considered in patients with decreased food or fluid intake and in patients with excessive somnolence [see Dosage and Administration (2.4)].

Monitoring: Drug Plasma Concentration

Since valproic acid may interact with concurrently administered drugs which are capable of enzyme induction, periodic plasma concentration determinations of valproate and concomitant drugs are recommended during the early course of therapy [see Drug Interactions (7)].

Effect on Ketone and Thyroid Function Tests

Valproate is partially eliminated in the urine as a keto-metabolite which may lead to a false interpretation of the urine ketone test.

There have been reports of altered thyroid function tests associated with valproate. The clinical significance of these is unknown.

Effect on HIV and CMV Viruses Replication

There are in vitro studies that suggest valproate stimulates the replication of the HIV and CMV viruses under certain experimental conditions. The clinical consequence, if any, is not known. Additionally, the relevance of these in vitro findings is uncertain for patients receiving maximally suppressive antiretroviral therapy. Nevertheless, these data should be borne in mind when interpreting the results from regular monitoring of the viral load in HIV-infected patients receiving valproate or when following CMV-infected patients clinically.

Valproic acid is a carboxylic acid designated as 2–propylpentanoic acid. It is also known as dipropylacetic acid. Valproic acid (pKa 4.8) has a molecular weight of 144 and occurs as a colorless liquid with a characteristic odor. It is slightly soluble in water (1.3 mg/ml) and very soluble in organic solvents. Valproic acid has the following structure:

Stavzor (valproic acid) delayed release capsules are for oral administration and are provided as orange-colored, oval- shaped capsules in 3 dosage strengths: 125 mg, 250 mg, 500 mg of valproic acid.

Inactive Ingredients

Stavzor (valproic acid) delayed release capsules also contain ammonium hydroxide, gelatin, glycerin, methacrylic acid copolymer, triethyl citrate, water, and FD&C Yellow No. 6 as the colorant. Each capsule is printed with Opacode WB as the black printing ink.

Mania

The effectiveness of valproate for the treatment of acute mania was demonstrated in two 3-week, placebo controlled, parallel group studies.

Study 1

The first study enrolled adult patients who met DSM-III-R criteria for bipolar disorder and who were hospitalized for acute mania. In addition, they had a history of failing to respond to or not tolerating previous lithium carbonate treatment. Valproate was initiated at a dose of 250 mg TID and adjusted to achieve serum valproate concentrations in a range of 50-100 mcg/mL by day 7. Mean valproate doses for completers in this study were 1118, 1525, and 2402 mg/day at Days 7, 14, and 21, respectively. Patients were assessed on the Young Mania Rating Scale (YMRS; score ranges from 0-60), an augmented Brief Psychiatric Rating Scale (BPRS-A), and the Global Assessment Scale (GAS). Baseline scores and change from baseline in the Week 3 endpoint (last-observation-carried-forward [LOCF]) analysis were as follows:

Valproate was statistically significantly superior to placebo on all three measures of outcome.

Study 2

The second study enrolled adult patients who met Research Diagnostic Criteria for manic disorder and who were hospitalized for acute mania. Valproate was initiated at a dose of 250 mg TID and adjusted within a dose range of 750-2500 mg/day to achieve serum valproate concentrations in a range of 40-150 mcg/mL. Mean valproate doses for completers in this study were 1116, 1683, and 2006 mg/day at Days 7, 14, and 21, respectively. Study 2 also included a lithium group for which lithium doses for completers were 1312, 1869, and 1984 mg/day at Days 7, 14, and 21, respectively. Patients were assessed on the Manic Rating Scale (MRS; score ranges from 11-63), and the primary outcome measures were the total MRS score, and scores for 2 subscales of the MRS, i.e., the Manic Syndrome Scale (MSS) and the Behavior and Ideation Scale (BIS). Baseline scores and change from baseline in the Week 3 endpoint (LOCF) analysis were as follows:

Valproate was statistically significantly superior to placebo on all three measures of outcome. An exploratory analysis for age and gender effects on outcome did not suggest any differential responsiveness on the basis of age or gender.

A comparison of the percentage of patients showing ≥30% reduction in the symptom score from baseline in each treatment group, separated by study, is shown in Figure 1.

Figure 1. Percentage of Patients Achieving ≥30% Reduction in Symptom Score From Baseline

Epilepsy

The efficacy of valproate in reducing the incidence of complex partial seizures (CPS) that occur in isolation or in association with other seizure types was established in 2 controlled trials.

In one, multiclinic, placebo-controlled study employing an add-on design, (adjunctive therapy) 144 patients who continued to suffer 8 or more CPS per 8 weeks during an 8- week period of monotherapy with doses of either carbamazepine or phenytoin sufficient to assure plasma concentrations within the "therapeutic range" were randomized to receive, in addition to their original antiepilepsy drug (AED), either valproate or placebo. Randomized patients were to be followed for a total of 16 weeks. The following Table presents the findings.

Figure 2 presents the proportion of patients (X axis) whose percentage reduction from baseline in complex partial seizure rates was at least as great as that indicated on the Y axis in the adjunctive therapy study. A positive percent reduction indicates an improvement (i.e., a decrease in seizure frequency), while a negative percent reduction indicates worsening. Thus, in a display of this type, the curve for an effective treatment is shifted to the left of the curve for placebo. This Figure shows that the proportion of patients achieving any particular level of improvement was consistently higher for valproate than for placebo. For example, 45% of patients treated with valproate had a ≥50% reduction in complex partial seizure rate compared to 23% of patients treated with placebo.

Figure 2.

The second study assessed the capacity of valproate to reduce the incidence of CPS when administered as the sole AED. The study compared the incidence of CPS among patients randomized to either a high- or low-dose treatment arm. Patients qualified for entry into the randomized comparison phase of this study only if 1) they continued to experience 2 or more CPS per 4 weeks during an 8- to 12- week long period of monotherapy with adequate doses of an AED (ie, phenytoin, carbamazepine, phenobarbital, or primidone) and 2) they made a successful transition over a 2-week interval to valproate. Patients entering the randomized phase were then brought to their assigned target dose, gradually tapered off their concomitant AED and followed for an interval as long as 22 weeks. Less than 50% of the patients randomized, however, completed the study. In patients converted to valproate monotherapy, the mean total valproate concentrations during monotherapy were 71 and 123 mcg/mL in the low-dose and high-dose groups, respectively.

The following Table presents the findings for all patients randomized who had at least one post-randomization assessment.

Figure 3 presents the proportion of patients (X axis) whose percentage reduction from baseline in complex partial seizure rates was at least as great as that indicated on the Y axis in the monotherapy study. A positive percent reduction indicates an improvement (i.e., a decrease in seizure frequency), while a negative percent reduction indicates worsening. Thus, in a display of this type, the curve for a more effective treatment is shifted to the left of the curve for a less effective treatment. This Figure shows that the proportion of patients achieving any particular level of reduction was consistently higher for high dose valproate than for low dose valproate. For example, when switching from carbamazepine, phenytoin, phenobarbital, or primidone monotherapy to high-dose valproate monotherapy, 63% of patients experienced no change or a reduction in complex partial seizure rates compared to 54% of patients receiving low-dose valproate.

Figure 3.

Migraine

The results of 2 multicenter, randomized, double-blind, placebo-controlled clinical trials established the effectiveness of valproate in the prophylactic treatment of migraine headache.

Both studies employed essentially identical designs and recruited patients with a history of migraine with or without aura (of at least 6 months in duration) who were experiencing at least 2 migraine headaches a month during the 3 months prior to enrollment. Patients with cluster headaches were excluded. Women of childbearing potential were excluded entirely from one study, but were permitted in the other if they were deemed to be practicing an effective method of contraception.

In each study following a 4-week single-blind placebo baseline period, patients were randomized, under double blind conditions, to valproate or placebo for a 12-week treatment phase, comprised of a 4-week dose titration period followed by an 8-week maintenance period. Treatment outcome was assessed on the basis of 4-week migraine headache rates during the treatment phase.

In the first study, a total of 107 patients (24 M, 83 F), ranging in age from 26 to 73 were randomized 2:1, valproate to placebo. Ninety patients completed the 8-week maintenance period. Drug dose titration, using 250-mg tablets, was individualized at the investigator's discretion. Adjustments were guided by actual/sham trough total serum valproate levels in order to maintain the study blind. In patients on valproate doses ranged from 500 to 2500 mg a day. Doses over 500 mg were given in 3 divided doses (TID). The mean dose during the treatment phase was 1087 mg/day resulting in a mean trough total valproate level of 72.5 mcg/mL, with a range of 31 to 133 mcg/mL.

The mean 4-week migraine headache rate during the treatment phase was 5.7 in the placebo group compared to 3.5 in the valproate group (see Figure 2). These rates were significantly different.

In the second study, a total of 176 patients (19 males and 157 females), ranging in age from 17 to 76 years, were randomized equally to one of three valproate dose groups (500, 1000, or 1500 mg/day) or placebo. The treatments were given in 2 divided doses (BID). One hundred thirty-seven patients completed the 8-week maintenance period. Efficacy was to be determined by a comparison of the 4-week migraine headache rate in the combined 1000/1500 mg/day group and placebo group.

The initial dose was 250 mg daily. The regimen was advanced by 250 mg every 4 days (8 days for 500 mg/day group), until the randomized dose was achieved. The mean trough total valproate levels during the treatment phase were 39.6, 62.5, and 72.5 mcg/mL in the valproate 500, 1000, and 1500 mg/day groups, respectively.

The mean 4-week migraine headache rates during the treatment phase, adjusted for differences in baseline rates, were 4.5 in the placebo group, compared to 3.3, 3.0, and 3.3 in the valproate 500, 1000, and 1500 mg/day groups, respectively, based on intent-to-treat results (see Figure 4). Migraine headache rates in the combined valproate 1000/1500 mg group were significantly lower than in the placebo group.

Figure 4. Mean 4-Week Migraine Rates

Applies to valproic acid: oral capsule delayed release, oral capsule liquid filled, oral syrup, oral tablet delayed release, oral tablet enteric coated, oral tablet extended release

Along with its needed effects, valproic acid (the active ingredient contained in Stavzor) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking valproic acid:

• Black, tarry stools
• bleeding gums
• bloating or swelling of the face, arms, hands, lower legs, or feet
• blood in the urine or stools
• confusion
• cough or hoarseness
• crying
• delusions
• dementia
• depersonalization
• diarrhea
• difficult or labored breathing
• dysphoria
• euphoria
• fever or chills
• general feeling of discomfort or illness
• headache
• joint pain
• loss of appetite
• lower back or side pain
• mental depression
• muscle aches and pains
• nausea
• nervousness
• painful or difficult urination
• paranoia
• pinpoint red spots on the skin
• quick to react or overreact emotionally
• rapid weight gain
• rapidly changing moods
• runny nose
• shakiness in the legs, arms, hands, or feet
• shivering
• sleepiness or unusual drowsiness
• sore throat
• sweating
• tightness in the chest
• tingling of the hands or feet
• trembling or shaking of the hands or feet
• trouble sleeping
• unusual bleeding or bruising
• unusual tiredness or weakness
• unusual weight gain or loss
• vomiting

• Abnormal dreams
• absence of or decrease in body movement
• anxiety
• bloody nose
• bloody or cloudy urine
• blurred vision
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• change in personality
• change in walking and balance
• changes in patterns and rhythms of speech
• chest pain
• chills
• clumsiness or unsteadiness
• cold sweats
• constipation
• darkened urine
• degenerative disease of the joint
• difficult, burning, or painful urination
• difficulty with moving
• discouragement
• dizziness
• dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
• dry mouth
• excessive muscle tone
• fast, irregular, pounding, or racing heartbeat or pulse
• fear
• feeling of warmth or heat
• feeling sad or empty
• flushing or redness of the skin, especially on the face and neck
• frequent urge to urinate
• heavy non-menstrual vaginal bleeding
• hyperventilation
• increased need to urinate
• indigestion
• irritability
• lack of appetite
• lack of coordination
• large, flat, blue or purplish patches in the skin
• leg cramps
• lip smacking or puckering
• loss of bladder control
• loss of interest or pleasure
• loss of strength or energy
• multiple swollen and inflamed skin lesions
• muscle pain or stiffness
• muscle tension or tightness
• normal menstrual bleeding occurring earlier, possibly lasting longer than expected
• pains in the stomach, side, or abdomen, possibly radiating to the back
• passing urine more often
• pounding in the ears
• puffing of the cheeks
• rapid or worm-like movements of the tongue
• rapid weight gain
• restlessness
• seeing, hearing, or feeling things that are not there
• shakiness and unsteady walk
• slurred speech
• small red or purple spots on the skin
• sweating
• swollen joints
• tiredness
• trouble with concentrating
• trouble with speaking
• twitching
• uncontrolled chewing movements
• uncontrolled movements of the arms and legs
• unsteadiness, trembling, or other problems with muscle control or coordination
• vomiting of blood or material that looks like coffee grounds
• yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking valproic acid:

• Change in consciousness
• fainting
• loss of consciousness
• slow or irregular heartbeat

Some side effects of valproic acid may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Acid or sour stomach
• belching
• body aches or pain
• change in vision
• congestion
• continuing ringing or buzzing or other unexplained noise in the ears
• hair loss or thinning of the hair
• hearing loss
• heartburn
• impaired vision
• lack or loss of strength
• loss of memory
• problems with memory
• rash
• seeing double
• tender, swollen glands in the neck
• trouble with swallowing
• uncontrolled eye movements
• voice changes
• weight gain
• weight loss

• Absent, missed, or irregular menstrual periods
• back pain
• burning, dry, or itching eyes
• change in taste or bad unusual or unpleasant (after) taste
• coin-shaped lesions on the skin
• cough producing mucus
• cramps
• dandruff
• discharge or excessive tearing
• dry skin
• earache
• excess air or gas in the stomach or intestines
• eye pain
• feeling of constant movement of self or surroundings
• full feeling
• heavy bleeding
• increased appetite
• itching of the vagina or genital area
• itching skin
• loss of bowel control
• neck pain
• oily skin
• pain
• pain during sexual intercourse
• pain or tenderness around the eyes and cheekbones
• passing gas
• rash with flat lesions or small raised lesions on the skin
• redness or swelling in the ear
• redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
• redness, swelling, or soreness of the tongue
• sensation of spinning
• sneezing
• stiff neck
• stopping of menstrual bleeding
• thick, white vaginal discharge with no odor or with a mild odor

Applies to valproic acid: injectable solution, intravenous solution, oral capsule, oral delayed release capsule, oral syrup

Cardiovascular

Common (1% to 10%): Edema, hypertension, hypotension, palpitations, postural hypotension, peripheral edema, tachycardia, vasodilation
Frequency not reported: Bradycardia, cutaneous vasculitis, hematoma formation[Ref]

Psychiatric

Very common (10% or more): Nervousness
Common (1% to 10%): Abnormal dreams, agitation, anxiety, aggression, confusion, depression, emotional lability, hallucinations, insomnia, personality disorder, thinking abnormalities
Rare (less than 0.1%): Abnormal behavior, learning disorder, psychomotor hyperactivity
Frequency not reported: Behavioral deterioration, hostility, psychosis[Ref]

Respiratory

Very common (10% or more): Flu syndrome, respiratory infection
Common (1% to 10%): Bronchitis, dyspnea, epistaxis, increased cough, pharyngitis, pneumonia, rhinitis, sinusitis
Uncommon (0.1% to 1%): Pleural effusion[Ref]

Renal

Rare (less than 0.1%): Reversible Fanconi's syndrome, tubulointerstitial nephritis[Ref]

Dermatologic

Very common (10% or more): Alopecia
Common (1% to 10%): Discoid lupus erythematosus, dry skin, ecchymosis, furunculosis, maculopapular rash, petechia, pruritus, rash, seborrhea
Uncommon (0.1% to 1%): Abnormal hair texture, abnormal hair growth, hair color changes, sweating
Rare (0.01% to 0.1%): Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis
Very rare (less than 0.01%): Acne, hirsutism
Frequency not reported: Angioedema, generalized pruritus, photosensitivity[Ref]

Endocrine

Uncommon (0.1% to 1%): Hyperandrogenism, syndrome of inappropriate ADH secretion
Rare (less than 0.1%): Hypothyroidism
Frequency not reported: Abnormal thyroid function tests, elevated serum testosterone concentrations, parotid gland swelling[Ref]

Gastrointestinal

Very common (10% or more): Abdominal pain, diarrhea, dyspepsia, gingival disorder, nausea, vomiting
Common (1% to 10%): Constipation, dry mouth, eructation, fecal incontinence, flatulence, gastralgia, gastroenteritis, glossitis, periodontal abscess, hematemesis, stomatitis
Uncommon (0.1% to 1%): Pancreatitis (life-threatening)[Ref]

General

The most commonly reported side effects at the start of therapy include nausea, vomiting, and indigestion; these effects are usually transient. Sedative effects occur most often in patients receiving combination therapy.[Ref]

Genitourinary

Common (1% to 10%): Amenorrhea, cystitis, dysmenorrhea, dysuria, enuresis, metrorrhagia, urinary incontinence, urinary frequency, vaginal hemorrhage, vaginitis
Very rare (less than 0.01%): Gynecomastia
Frequency not reported: Breast enlargement, galactorrhea, polycystic ovary disease[Ref]

Hematologic

Very common (10% or more): Thrombocytopenia
Common (1% to 10%): Anemia, hemorrhage
Uncommon (0.1% to 1%): Leucopenia, pancytopenia
Rare (less than 0.1%): Abnormal coagulation tests (e.g., prolonged prothrombin time, prolonged activated partial thromboplastin time, prolonged thrombin time, prolonged INR), agranulocytosis, bone marrow failure, decreased coagulation factors, including pure red cell aplasia, macrocytosis
Frequency not reported: Aplastic anemia, bone marrow suppression, bruising, eosinophilia, frank hemorrhage, hypofibrinogenemia, anemia including macrocytic with or without folate deficiency, relative lymphocytosis[Ref]

Hepatic

Common (1% to 10%): Increased liver enzymes (particularly early in treatment), liver injury, SGOT increased, SGPT increased
Frequency not reported: Severe liver damage (including hepatic failure sometimes resulting in death), increased serum bilirubin, abnormal changes in other liver function tests[Ref]

Hypersensitivity

Frequency not reported: Allergic reaction, anaphylaxis, hypersensitivity[Ref]

Local

Common (1% to 10%): Injection site pain, injection site reaction
Uncommon (0.1% to 1%): Injection site inflammation[Ref]

Metabolic

Very common (10% or more): Anorexia
Common (1% to 10%): Weight loss/gain, increased appetite, hyponatremia
Rare (less than 0.1%): Hyperammonemia
Frequency not reported: Acute intermittent porphyria, minor elevations of LDH (dose related), decreased carnitine concentrations, hyperglycinemia[Ref]

Musculoskeletal

Common (1% to 10%): Arthralgia, arthrosis, leg cramps, myalgia, myasthenia, twitching
Uncommon (0.1% to 1%): Decreased bone mineral density, osteopenia, osteoporosis and fractures on long term therapy
Rare (less than 0.1%): Rhabdomyolysis, systemic lupus erythematosus
Frequency not reported: Bone pain[Ref]

Nervous system

Very common (10% or more): Dizziness, headache, somnolence, tremor
Common (1% to 10%): Abnormal gait, amnesia, catatonic reaction, convulsion, disturbance in attention, dysarthria, extrapyramidal disorder, hypertonia, hypokinesia, incoordination, increased reflexes, memory impairment, nystagmus, paraesthesia, speech disorder, stupor, tardive dyskinesia, taste perversion
Uncommon (0.1% to 1%): Ataxia, coma, encephalopathy, lethargy, reversible parkinsonism
Rare (less than 0.1%): Cognitive disorder, reversible dementia associated with reversible cerebral atrophy
Frequency not reported: Cerebral atrophy, dementia[Ref]

Ocular

Very common (10% or more): Amblyopia/blurred vision, diplopia
Common (1% to 10%): Abnormal vision, conjunctivitis, diplopia, dry eyes, eye pain[Ref]

Oncologic

Rare (less than 0.1%): Myelodysplastic syndrome[Ref]

Other

Very common (10% or more): Asthenia
Common (1% to 10%): Back pain, chills, deafness, ear disorder, ear pain, face edema, fever, malaise, otitis media, tinnitus, vertigo
Frequency not reported: Hypothermia, weakness[Ref]

Some side effects of Stavzor may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.