Rimantadine (Flumadine)

• Type of Drug: Antiviral.
• Prescribed for: Preventing and treating influenza A viral infections.

Rimantadine (Flumadine) General Information

Rimantadine is a synthetic antiviral agent that appears to interfere with the reproduction of various strains of the influenza A virus, a common cause of viral illness. Annual vaccination against the influenza virus is recommended as the best way of preventing the flu, but it takes 2 to 4 weeks to develop immunity; Rimantadine may be taken during that time to prevent viral infection in certain high-risk people or those whose exposure to the virus might be more dangerous.

Rimantadine (Flumadine) Cautions and Warnings

People with severe liver or kidney disease clear this drug from their bodies only half as fast as those with normal organ function; they will need to have their dosage adjusted based on those factors.
People with a history of seizures are likely to suffer another one while taking this medicine. Call your doctor if this happens.

The influenza virus may become resistant to Rimantadine in up to 30 percent of people taking the drug. If this happens, the resistant influenza virus could infect others who may not have been vaccinated.

Possible Side Effects

• Most common: sleeplessness, nervousness, loss of concentration, headache, fatigue, weakness, nausea, vomiting, loss of appetite, dry mouth, and abdominal pains.
• Less common: diarrhea, upset stomach, dizziness, depression, euphoria (feeling “high”), changes in the way you walk, tremors, hallucinations, convulsions, fainting, ringing or buzzing in the ears, changes or loss in the senses of taste or smell, breathing difficulty, skin pallor, rash, heart palpitations, rapid heartbeat, high blood pressure, heart failure, swelling of the ankles or feet, and heart block.
• Rare: constipation, swallowing difficulty, mouth sores, agitation, sweating, diminished sense of touch, eye pain or tearing, cough, bronchospasm, increased urination, fever, and fluid oozing from the nipples (women only).

Rimantadine (Flumadine) Drug Interactions

• The importance of Rimantadine’s interactions is not known because there is no established relationship between the amount of drug in the blood and its antiviral effect. Aspirin and Acetaminophen may reduce the amount of Rimantadine in the blood by about 10 percent. Cimetidine increases the rate at which Rimantadine is broken down by the liver.

Food Interactions

Rimantadine is best taken on an empty stomach, or at least 1 hour before or 2 hours after meals. You may take it with food if it upsets your stomach.

Usual Dose

Adult and Child (age 10 and older): 100 mg twice per day.
Child (under age 10): 2.25 mg per pound of body weight, up to 150 mg, taken once a day.
People with severe liver or kidney disease: up to 100 mg per day.

Rimantadine (Flumadine) Overdosage

Symptoms of overdosage are likely to be reflected in nervous-system (agitation, hallucination) and cardiac (abnormal heart rhythms) side effects. Overdose victims should be given Syrup of Ipecac (available at any pharmacy) as soon as possible to remove any remaining drug from their stomach. Follow package directions and give ipecac only to conscious overdose victims. Call your local poison control center or hospital emergency room before giving Ipecac. ALWAYS bring the medicine bottle if you go to a hospital for treatment.

Rimantadine (Flumadine) Special Information

Rimantadine may be given to children to prevent influenza infection, but it is not recommended for treatment of their flu symptoms.

Call your doctor if you develop seizures, convulsions, or any other serious or unusual side effects.
If you forget a dose of Rimantadine, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.

Special Populations

Pregnancy/Breast-feeding
In animal studies, Rimantadine was found to be toxic to developing fetuses; pregnant animals given 11 times the human dose experienced drug side effects. Pregnant women should take Rimantadine only after fully discussing its risks and benefits with their doctor.

Animal studies of Rimantadine showed breast milk levels twice the blood level within 2 to 3 hours. Nursing mothers taking Rimantadine should bottle-feed their babies.

Seniors
Older adults are more likely to suffer from Rimantadine side effects of the nervous system, stomach, or intestines. Elderly nursing-home patients should receive no more than 100 mg of Rimantadine per day because of the likelihood that they have liver or kidney dysfunction. Otherwise healthy seniors may take this drug without special restriction.