Dihydroergotamine Nasal Spray

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
• Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.
• Chest pain or pressure.
• Fast or slow heartbeat.
• A heartbeat that does not feel normal.
• Dizziness or passing out.
• Change in color of hands or feet from pale to blue or red.
• Numbness, pain, tingling, or cold feeling of the hands or feet.
• Any sores or wounds on the fingers or toes.
• Muscle pain or weakness.
• Muscle cramps.
• Swelling.
• Very bad nose irritation.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Upset stomach or throwing up.
• Nose and throat irritation.
• Change in taste.
• Nosebleed.
• Stuffy nose.
• Runny nose.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

Dihydroergotamine mesylate, USP is ergotamine hydrogenated in the 9,10 position as the mesylate salt. Dihydroergotamine mesylate, USP is known chemically as ergotaman-3', 6', 18-trione, 9,10-dihydro-12'-hydroxy-2'-methyl-5'- (phenylmethyl)-, (5'α)-, monomethanesulfonate. Its molecular weight is 679.80 and its empirical formula is C33H37N5O5•CH4O3S.

The chemical structure is:

Dihydroergotamine mesylate, USP nasal spray is provided for intranasal administration as a clear, colorless to faintly yellow solution in an amber glass vial containing:

Mechanism of Action

Dihydroergotamine binds with high affinity to 5-HT1Dα and 5-HT1Dβ receptors. It also binds with high affinity to serotonin 5-HT1A, 5-HT2A, and 5-HT2C receptors, noradrenaline α2A, α2B and α1 receptors, and dopamine D2L and D3 receptors.

The therapeutic activity of dihydroergotamine in migraine is generally attributed to the agonist effect at 5-HT1D receptors. Two current theories have been proposed to explain the efficacy of 5-HT1D receptor agonists in migraine. One theory suggests that activation of 5-HT1D receptors located on intracranial blood vessels, including those on arterio-venous anastomoses, leads to vasoconstriction, which correlates with the relief of migraine headache. The alternative hypothesis suggests that activation of 5-HT1D receptors on sensory nerve endings of the trigeminal system results in the inhibition of pro-inflammatory neuropeptide release. In addition, dihydroergotamine possesses oxytocic properties. (See CONTRAINDICATIONS)

Pharmacokinetics

Dihydroergotamine mesylate is poorly bioavailable following oral administration. Following intranasal administration, however, the mean bioavailability of dihydroergotamine mesylate is 32% relative to the injectable administration. Absorption is variable, probably reflecting both intersubject differences of absorption and the technique used for self-administration.

Dihydroergotamine mesylate is 93% plasma protein bound. The apparent steady-state volume of distribution is approximately 800 liters.

Four dihydroergotamine mesylate metabolites have been identified in human plasma following oral administration. The major metabolite, 8'-β-hydroxydihydroergotamine, exhibits affinity equivalent to its parent for adrenergic and 5-HT receptors and demonstrates equivalent potency in several venoconstrictor activity models, in vivo and in vitro. The other metabolites, i.e., dihydrolysergic acid, dihydrolysergic amide and a metabolite formed by oxidative opening of the proline ring are of minor importance. Following nasal administration, total metabolites represent only 20%-30% of plasma AUC. The systemic clearance of dihydroergotamine mesylate following I.V. and I.M. administration is 1.5 L/min. Quantitative pharmacokinetic characterization of the four metabolites has not been performed.

The major excretory route of dihydroergotamine is via the bile in the feces. After intranasal administration the urinary recovery of parent drug amounts to about 2% of the administered dose compared to 6% after I.M. administration. The total body clearance is 1.5 L/min which reflects mainly hepatic clearance. The renal clearance (0.1 L/min) is unaffected by the route of dihydroergotamine administration. The decline of plasma dihydroergotamine is biphasic with a terminal half-life of about 10 hours.

No studies have been conducted on the effect of renal or hepatic impairment, gender, race, or ethnicity on dihydroergotamine pharmacokinetics. Dihydroergotamine mesylate, USP nasal spray is contraindicated in patients with severely impaired hepatic or renal function. (See CONTRAINDICATIONS)

The pharmacokinetics of dihydroergotamine did not appear to be significantly affected by the concomitant use of a local vasoconstrictor (e.g., fenoxazoline).

Multiple oral doses of the β-adrenoceptor antagonist propranolol, used for migraine prophylaxis, had no significant influence on the Cmax, Tmax or AUC of dihydroergotamine doses up to 4 mg. Pharmacokinetic interactions have been reported in patients treated orally with other ergot alkaloids (e.g., increased levels of ergotamine) and macrolide antibiotics, principally troleandomycin, presumably due to inhibition of cytochrome P450 3A metabolism of the alkaloids by troleandomycin. Dihydroergotamine has also been shown to be an inhibitor of cytochrome P450 3A catalyzed reactions and rare reports of ergotism have been obtained from patients treated with dihydroergotamine and macrolide antibiotics (e.g., troleandomycin, clarithromycin, erythromycin), and in patients treated with dihydroergotamine and protease inhibitors (e.g. ritonavir), presumably due to inhibition of cytochrome P450 3A metabolism of ergotamine (See CONTRAINDICATIONS). No pharmacokinetic interactions involving other cytochrome P450 isoenzymes are known.

The efficacy of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray for the acute treatment of migraine headaches was evaluated in four randomized, double blind, placebo controlled studies in the U.S. The patient population for the trials was predominantly female (87%) and Caucasian (95%) with a mean age of 39 years (range 18 to 65 years). Patients treated a single moderate to severe migraine headache with a single dose of study medication and assessed pain severity over the 24 hours following treatment. Headache response was determined 0.5, 1, 2, 3 and 4 hours after dosing and was defined as a reduction in headache severity to mild or no pain. In studies 1 and 2, a four-point pain intensity scale was utilized; in studies 3 and 4, a five-point scale was used that included both pain response and restoration of function for "severe" or "incapacitating" pain, a less clear endpoint. Although rescue medication was allowed in all four studies, patients were instructed not to use them during the four hour observation period. In studies 3 and 4, a total dose of 2 mg was compared to placebo. In studies 1 and 2, doses of 2 and 3 mg were evaluated, and showed no advantage of the higher dose for a single treatment. In all studies, patients received a regimen consisting of 0.5 mg in each nostril, repeated in 15 minutes (and again in another 15 minutes for the 3 mg dose in studies 1 and 2).

The percentage of patients achieving headache response 4 hours after treatment was significantly greater in patients receiving 2 mg doses of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray compared to those receiving placebo in 3 of the 4 studies (see Tables 1 & 2 and Figures 1 & 2).

Comparisons of drug performance based upon results obtained in different clinical trials are never reliable. Because studies are conducted at different times, with different samples of patients, by different investigators, employing different criteria and/or different interpretations of the same criteria, under different conditions (dose, dosing regimen, etc.), quantitative estimates of treatment response and the timing of response may be expected to vary considerably from study to study.

The Kaplan-Meier plots below (Figures 1 & 2) provides an estimate of the probability that a patient will have responded to a single 2 mg dose of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray as a function of the time elapsed since initiation of treatment.

* The figure shows the probability over time of obtaining a response following treatment with Migranal® (dihydroergotamine mesylate, USP) Nasal Spray. Headache response was based on pain intensity as interpreted by the patient using a four-point pain intensity scale. Patients not achieving response within 4 hours were censored to 4 hours.

* The figure shows the probability over time of obtaining a response following treatment with Migranal® (dihydroergotamine mesylate, USP) Nasal Spray. Headache response was evaluated on a five-point scale that confounded pain response and restoration of function for "severe" or "incapacitating" pain. Patients not achieving response within 4 hours were censored to 4 hours.

For patients with migraine-associated nausea, photophobia, and phonophobia at baseline, there was a lower incidence of these symptoms at 2 and 4 hours following administration of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray compared to placebo.

Patients were not allowed to use additional treatments for eight hours prior to study medication dosing and during the four hour observation period following study treatment. Following the 4 hour observation period, patients were allowed to use additional treatments. For all studies, the estimated probability of patients using additional treatments for their migraines over the 24 hours following the single 2 mg dose of study treatment is summarized in Figure 3 below.

* Kaplan-Meier plot based on data obtained from all studies with patients not using additional treatments censored to 24 hours. All patients received a single treatment of study medication for their migraine attack. The plot also includes patients who had no response to the initial dose.

Neither age nor sex appear to effect the patient's response to Migranal® (dihydroergotamine mesylate, USP) Nasal Spray. While patients with menstrual migraine, migraine with aura, and migraine without aura by medical history were included in the clinical evaluation of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray, patients were not required to report the specific type of migraine treated with study medication. Thus, neither the effect of menses on migraine nor the presence or the absence of aura were assessed. The racial distribution of patients was insufficient to determine the effect of race on the efficacy of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray.

General

Dihydroergotamine mesylate, USP nasal spray may cause coronary artery vasospasm; patients who experience signs or symptoms suggestive of angina following its administration should, therefore, be evaluated for the presence of CAD or a predisposition to variant angina before receiving additional doses. Similarly, patients who experience other symptoms or signs suggestive of decreased arterial flow, such as ischemic bowel syndrome or Raynaud's syndrome following the use of any 5-HT agonist are candidates for further evaluation. (See WARNINGS).

see WARNINGS: Fibrotic Complications

Information for Patients

The text of a patient information sheet is printed at the end of this insert. To assure safe and effective use of dihydroergotamine mesylate, USP nasal spray, the information and instructions provided in the patient information sheet should be discussed with patients.

Once the nasal spray applicator has been prepared, it should be discarded (with any remaining drug) after 8 hours.

Patients should be advised to report to the physician immediately any of the following: numbness or tingling in the fingers and toes, muscle pain in the arms and legs, weakness in the legs, pain in the chest, temporary speeding or slowing of the heart rate, swelling, or itching.

Prior to the initial use of the product by a patient, the prescriber should take steps to ensure that the patient understands how to use the product as provided. (See Patient Information Sheet and product packaging).

Administration of dihydroergotamine mesylate, USP nasal spray, should not exceed the dosing guidelines and should not be used for chronic daily administration (see DOSAGE AND ADMINISTRATION).

Drug Interactions

Dihydroergotamine mesylate, USP nasal spray should not be used with peripheral vasoconstrictors because the combination may cause synergistic elevation of blood pressure.

Sumatriptan has been reported to cause coronary artery vasospasm, and its effect could be additive with dihydroergotamine mesylate, USP nasal spray. Sumatriptan and dihydroergotamine mesylate, USP nasal spray should not be taken within 24 hours of each other. (See CONTRAINDICATIONS)

Although the results of a clinical study did not indicate a safety problem associated with the administration of dihydroergotamine mesylate, USP nasal spray to subjects already receiving propranolol, there have been reports that propranolol may potentiate the vasoconstrictive action of ergotamine by blocking the vasodilating property of epinephrine.

Nicotine may provoke vasoconstriction in some patients, predisposing to a greater ischemic response to ergot therapy.

See CONTRAINDICATIONS and WARNINGS.

Weakness, hyperreflexia, and incoordination have been reported rarely when 5HT1 agonists have been coadministered with SSRI's (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline). There have been no reported cases from spontaneous reports of drug interaction between SSRI's and dihydroergotamine mesylate, USP nasal spray or D.H.E. 45®.

The effect of oral contraceptives on the pharmacokinetics of dihydroergotamine mesylate, USP nasal spray has not been studied.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Assessment of the carcinogenic potential of dihydroergotamine mesylate in mice and rats is ongoing.

Dihydroergotamine mesylate was clastogenic in two in vitro chromosomal aberration assays, the V79 Chinese hamster cell assay with metabolic activation and the cultured human peripheral blood lymphocyte assay. There was no evidence of mutagenic potential when dihydroergotamine mesylate was tested in the presence or absence of metabolic activation in two gene mutation assays (the Ames test and the in vitro mammalian Chinese hamster V79/HGPRT assay) and in an assay for DNA damage (the rat hepatocyte unscheduled DNA synthesis test). Dihydroergotamine was not clastogenic in the in vivo mouse and hamster micronucleus tests.

There was no evidence of impairment of fertility in rats given intranasal doses of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray up to 1.6 mg/day (associated with mean plasma dihydroergotamine mesylate exposures [AUC] approximately 9 to 11 times those in humans receiving the MRDD of 4 mg).

Pregnancy

See CONTRAINDICATIONS.

Nursing Mothers

Ergot drugs are known to inhibit prolactin. It is likely that dihydroergotamine mesylate, USP nasal spray is excreted in human milk, but there are no data on the concentration of dihydroergotamine in human milk. It is known that ergotamine is excreted in breast milk and may cause vomiting, diarrhea, weak pulse, and unstable blood pressure in nursing infants. Because of the potential for these serious adverse events in nursing infants exposed to dihydroergotamine mesylate, USP nasal spray, nursing should not be undertaken with the use of dihydroergotamine mesylate, USP nasal spray. (See CONTRAINDICATIONS)

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Use in the Elderly

There is no information about the safety and effectiveness of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray in this population because patients over age 65 were excluded from the controlled clinical trials.

During clinical studies and the foreign postmarketing experience with Migranal® (dihydroergotamine mesylate, USP) Nasal Spray there have been no fatalities due to cardiac events.

Serious cardiac events, including some that have been fatal, have occurred following use of the parenteral form of dihydroergotamine mesylate (D.H.E. 45® Injection), but are extremely rare. Events reported have included coronary artery vasospasm, transient myocardial ischemia, myocardial infarction, ventricular tachycardia, and ventricular fibrillation. (See CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS).

Fibrotic complications have been reported in association with long term use of injectable dihydroergotamine mesylate (see WARNINGS: Fibrotic Complications).

Incidence in Controlled Clinical Trials

Of the 1,796 patients and subjects treated with Migranal® (dihydroergotamine mesylate, USP) Nasal Spray doses 2 mg or less in U.S. and foreign clinical studies, 26 (1.4%) discontinued because of adverse events. The adverse events associated with discontinuation were, in decreasing order of frequency: rhinitis 13, dizziness 2, facial edema 2, and one each due to cold sweats, accidental trauma, depression, elective surgery, somnolence, allergy, vomiting, hypotension, and paraesthesia.

The most commonly reported adverse events associated with the use of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray during placebo-controlled, double-blind studies for the treatment of migraine headache and not reported at an equal incidence by placebo-treated patients were rhinitis, altered sense of taste, application site reactions, dizziness, nausea, and vomiting. The events cited reflect experience gained under closely monitored conditions of clinical trials in a highly selected patient population. In actual clinical practice or in other clinical trials, these frequency estimates may not apply, as the conditions of use, reporting behavior, and the kinds of patients treated may differ.

Migranal® (dihydroergotamine mesylate, USP) Nasal Spray was generally well tolerated. In most instances these events were transient and self-limited and did not result in patient discontinuation from a study. The following table summarizes the incidence rates of adverse events reported by at least 1% of patients who received Migranal® (dihydroergotamine mesylate, USP) Nasal Spray for the treatment of migraine headaches during placebo-controlled, double-blind clinical studies and were more frequent than in those patients receiving placebo.

Other Adverse Events During Clinical Trials

In the paragraphs that follow, the frequencies of less commonly reported adverse clinical events are presented. Because the reports include events observed in open and uncontrolled studies, the role of Migranal® (dihydroergotamine mesylate, USP) Nasal Spray in their causation cannot be reliably determined. Furthermore, variability associated with adverse event reporting, the terminology used to describe adverse events, etc., limit the value of the quantitative frequency estimates provided. Event frequencies are calculated as the number of patients who used Migranal® (dihydroergotamine mesylate, USP) Nasal Spray in placebo-controlled trials and reported an event divided by the total number of patients (n=1796) exposed to Migranal® (dihydroergotamine mesylate, USP) Nasal Spray. All reported events are included except those already listed in the previous table, those too general to be informative, and those not reasonably associated with the use of the drug. Events are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse events are defined as those occurring in at least 1/100 patients; infrequent adverse events are those occurring in 1/100 to 1/1,000 patients; and rare adverse events are those occurring in fewer than 1/1,000 patients.

Skin and Appendages: Infrequent: petechia, pruritus, rash, cold clammy skin; Rare: papular rash, urticaria, herpes simplex.

Musculoskeletal: Infrequent: cramps, myalgia, muscular weakness, dystonia; Rare: arthralgia, involuntary muscle contractions, rigidity.

Central and Peripheral Nervous System: Infrequent: confusion, tremor, hypoesthesia, vertigo; Rare: speech disorder, hyperkinesia, stupor, abnormal gait, aggravated migraine.

Autonomic Nervous System: Infrequent: increased sweating.

Special Senses: Infrequent: sense of smell altered, photophobia, conjunctivitis, abnormal lacrimation, abnormal vision, tinnitus, earache; Rare: eye pain.

Psychiatric: Infrequent: nervousness, euphoria, insomnia, concentration impaired; Rare: anxiety, anorexia, depression.

Gastrointestinal: Infrequent: abdominal pain, dyspepsia, dysphagia, hiccup; Rare: increased salivation, esophagospasm.

Cardiovascular: Infrequent: edema, palpitation, tachycardia; Rare: hypotension, peripheral ischemia, angina.

Respiratory System: Infrequent: dyspnea, upper respiratory tract infections; Rare: bronchospasm, bronchitis, pleural pain, epistaxis.

Urinary System: Infrequent: increased frequency of micturition, cystitis.

Reproductive, Female: Rare: pelvic inflammation, vaginitis.

Body as a Whole - General: Infrequent: feeling cold, malaise, rigors, fever, periorbital edema; Rare: flu-like symptoms, shock, loss of voice, yawning.

Application Site: Infrequent: local anesthesia.

Post-introduction Reports

Voluntary reports of adverse events temporally associated with dihydroergotamine products used in the management of migraine that have been received since the introduction of the injectable formulation are included in this section save for those already listed above. Because of their source (open and uncontrolled clinical use), whether or not events reported in association with the use of dihydroergotamine are causally related to it cannot be determined. There have been reports of pleural and retroperitoneal fibrosis in patients following prolonged daily use of injectable dihydroergotamine mesylate. Dihydroergotamine mesylate, USP nasal spray is not recommended for prolonged daily use. (See DOSAGE AND ADMINISTRATION)

To date, there have been no reports of acute overdosage with this drug. Due to the risk of vascular spasm, exceeding the recommended dosages of dihydroergotamine mesylate, USP nasal spray is to be avoided.

Excessive doses of dihydroergotamine may result in peripheral signs and symptoms of ergotism. Treatment includes discontinuance of the drug, local application of warmth to the affected area, the administration of vasodilators, and nursing care to prevent tissue damage.

In general, the symptoms of an acute dihydroergotamine mesylate, USP nasal spray overdose are similar to those of an ergotamine overdose, although there is less pronounced nausea and vomiting with dihydroergotamine mesylate, USP nasal spray. The symptoms of an ergotamine overdose include the following: numbness, tingling, pain, and cyanosis of the extremities associated with diminished or absent peripheral pulses; respiratory depression; an increase and/or decrease in blood pressure, usually in that order; confusion, delirium, convulsions, and coma; and/or some degree of nausea, vomiting, and abdominal pain.

In laboratory animals, significant lethality occurs when dihydroergotamine is given at I.V. doses of 44 mg/kg in mice, 130 mg/kg in rats, and 37 mg/kg in rabbits.

Up-to-date information about the treatment of overdosage can often be obtained from a certified Regional Poison Control Center. Telephone numbers of certified Poison Control Centers are listed in the Physicians' Desk Reference® (PDR).