Phrenilin

• IPI Pharmaceuticals

• PD-Rx Pharmaceuticals, Inc.

• Quality Care Pharmaceuticals

• Valeant Pharmaceuticals International

• Valeant Pharmaceuticals North America LLC

Phrenilin is part of the drug class:

• Anilides

Along with its needed effects, a medicine 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:

• Bleeding or crusting sores on lips
• chest pain
• fever with or without chills
• hive-like swellings (large) on eyelids, face, lips, and/or tongue
• muscle cramps or pain
• red, thickened, or scaly skin
• shortness of breath, troubled breathing, tightness in chest, or wheezing
• skin rash, itching, or hives
• sores, ulcers, or white spots in mouth (painful)

• Anxiety, confusion, excitement, irritability, nervousness, restlessness, or trouble in sleeping (severe, especially with products containing caffeine)
• convulsions (seizures) (for products containing caffeine)
• diarrhea, especially if occurring together with increased sweating, loss of appetite, and stomach cramps or pain
• dizziness, lightheadedness, drowsiness, or weakness, (severe)
• frequent urination (for products containing caffeine)
• hallucinations (seeing, hearing, or feeling things that are not there)
• increased sensitivity to touch or pain (for products containing caffeine)
• muscle trembling or twitching (for products containing caffeine)
• nausea or vomiting, sometimes with blood
• ringing or other sounds in ears (for products containing caffeine)
• seeing flashes of "zig-zag" lights (for products containing caffeine)
• shortness of breath or unusually slow or troubled breathing
• slow, fast, or irregular heartbeat
• slurred speech
• staggering
• swelling, pain, or tenderness in the upper abdomen or stomach area
• unusual movements of the eyes

Check with your doctor as soon as possible if any of the following side effects occur:

• Confusion (mild)
• mental depression
• unusual excitement (mild)

• Bloody or black, tarry stools
• bloody urine
• pinpoint red spots on skin
• swollen or painful glands
• unusual bleeding or bruising
• unusual tiredness or weakness (mild

Some side effects 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:

• Bloated or "gassy" feeling
• dizziness or lightheadedness (mild)
• drowsiness (mild)
• nausea, vomiting, or stomach pain (occurring without other symptoms of overdose)

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Phrenilin®: Each Phrenilin® tablet for oral administration, contains Butalbital, USP 50 mg, Acetaminophen, USP 325 mg.

In addition each Phrenilin® tablet contains the following inactive ingredients: alginic acid, corn starch, D&C Red No. 27 - Aluminum Lake, FD&C Blue No. 1 - Aluminum Lake, gelatin, magnesium stearate, microcrystalline cellulose and pregelatinized starch.

Butalbital (5-allyl-5-isobutylbarbituric acid), a slightly bitter, white, odorless, crystalline powder, is a short to intermediate-acting barbiturate. It has the following structural formula:

C11H16N2O3                    M.W. = 224.26

C11H16N2O3                    M.W. = 224.26

C11H16N2O3                    M.W. = 224.26

Acetaminophen (4'-hydroxyacetanilide), a slightly bitter, white, odorless, crystalline powder, is a non-opiate, non-salicylate analgesic and antipyretic. It has the following structural formula:

C8H9NO2          M.W. = 151.16

General:

Phrenilin® tablets should be prescribed with caution in certain special-risk patients, such as the elderly or debilitated, and those with severe impairment of renal or hepatic function, or acute abdominal conditions.

INFORMATION FOR PATIENTS/CAREGIVERS

This product may impair mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. Such tasks should be avoided while taking this product.

Alcohol and other CNS depressants may produce an additive CNS depression, when taken with this combination product, and should be avoided.

Butalbital may be habit-forming. Patients should take the drug only for as long as it is prescribed, in the amounts prescribed, and no more frequently than prescribed.

Laboratory Tests:

In patients with severe hepatic or renal disease, effects of therapy should be monitored with serial liver and/or renal function tests.

Drug Interactions:

The CNS effects of butalbital may be enhanced by monoamine oxidase (MAO) inhibitors.

Butalbital and acetaminophen may enhance the effects of: other narcotic analgesics, alcohol, general anesthetics, tranquilizers such as chlordiazepoxide, sedative-hypnotics, or other CNS depressants, causing increased CNS depression.

Drug/Laboratory Test Interactions:

Acetaminophen may produce false-positive test results for urinary 5-hydroxyindoleacetic acid.

Carcinogenesis, Mutagenesis, Impairment of Fertility:

No adequate studies have been conducted in animals to determine whether acetaminophen or butalbital have a potential for carcinogenesis, mutagenesis or impairment of fertility.

Pregnancy:

Teratogenic Effects: Pregnancy Category C: Animal reproduction studies have not been conducted with this combination product. It is also not known whether butalbital and acetaminophen can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. These products should be given to a pregnant woman only when clearly needed.

Nonteratogenic Effects: Withdrawal seizures were reported in a two-day-old male infant whose mother had taken a butalbital-containing drug during the last two months of pregnancy. Butalbital was found in the infant's serum. The infant was given phenobarbital 5 mg/kg, which was tapered without further seizure or other withdrawal symptoms.

Nursing Mothers:

Barbiturates and acetaminophen are excreted in breast milk in small amounts, but the significance of their effects on nursing infants is not known. Because of potential for serious adverse reactions in nursing infants from butalbital and acetaminophen, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use:

Safety and effectiveness in children below the age of 12 have not been established.

Abuse and Dependence: Butalbital: Barbiturates may be habit-forming: Tolerance, psychological dependence, and physical dependence may occur especially following prolonged use of high doses of barbiturates. The average daily dose for the barbiturate addict is usually about 1500 mg. As tolerance to barbiturates develops, the amount needed to maintain the same level of intoxication increases; tolerance to a fatal dosage, however, does not increase more than two-fold. As this occurs, the margin between an intoxication dosage and fatal dosage becomes smaller. The lethal dose of a barbiturate is far less if alcohol is also ingested. Major withdrawal symptoms (convulsions and delirium) may occur within 16 hours and last up to 5 days after abrupt cessation of these drugs. Intensity of withdrawal symptoms gradually declines over a period of approximately 15 days. Treatment of barbiturate dependence consists of cautious and gradual withdrawal of the drug. Barbiturate-dependent patients can be withdrawn by using a number of different withdrawal regimens. One method involves initiating treatment at the patient's regular dosage level and gradually decreasing the daily dosage as tolerated by the patient.

Following an acute overdosage of butalbital and acetaminophen, toxicity may result from the barbiturate or the acetaminophen.

Signs and Symptoms: Toxicity from barbiturate poisoning includes drowsiness, confusion, and coma; respiratory depression; hypotension; and hypovolemic shock.

In acetaminophen overdosage: dose-dependent, potentially fatal hepatic necrosis is the most serious adverse effect. Renal tubular necrosis, hypoglycemic coma and coagulation defects may also occur. Early symptoms following a potentially hepatotoxic overdose may include: nausea, vomiting, diaphoresis and general malaise. Clinical and laboratory evidence of hepatic toxicity may not be apparent until 48 to 72 hours post-ingestion.

Treatment: A single or multiple drug overdose with butalbital and acetaminophen is a potentially lethal polydrug overdose, and consultation with a regional poison control center is recommended.

Immediate treatment includes support of cardiorespiratory function and measures to reduce drug absorption.

Oxygen, intravenous fluids, vasopressors, and other supportive measures should be employed as indicated. Assisted or controlled ventilation should also be considered.

Gastric decontamination with activated charcoal should be administered just prior to N-acetylcysteine (NAC) to decrease systemic absorption if acetaminophen ingestion is known or suspected to have occurred within a few hours of presentation. Serum acetaminophen levels should be obtained immediately if the patient presents 4 hours or more after ingestion to assess potential risk of hepatotoxicity; acetaminophen levels drawn less than 4 hours post-ingestion may be misleading. To obtain the best possible outcome, NAC should be administered as soon as possible where impending or evolving liver injury is suspected. Intravenous NAC may be administered when circumstances preclude oral administration.

Vigorous supportive therapy is required in severe intoxication. Procedures to limit the continuing absorption of the drug must be readily performed since the hepatic injury is dose dependent and occurs early in the course of intoxication.

NDC 0187-0842-01

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Applies to acetaminophen / butalbital: oral capsule, oral tablet

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:

• Dizziness.
• Feeling sleepy.
• Belly pain.
• Upset stomach or throwing up.

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.