Usual Adult Dose for Influenza A

100 mg orally twice a day for 7 days

Comments:

• The adamantanes (amantadine and rimantadine) are not recommended for use in the US at this time because of widespread antiviral resistance in circulating influenza A viruses.
• Therapy should be initiated as soon as possible, preferably within 48 hours after onset of signs and symptoms of influenza A infection; therapy should be continued for approximately 7 days from the initial onset of symptoms.

Use: For the treatment of illness caused by various strains of influenza A virus.

Usual Adult Dose for Influenza Prophylaxis

100 mg orally twice a day

Comments:

• The adamantanes (amantadine and rimantadine) are not recommended for use in the US at this time because of widespread antiviral resistance in circulating influenza A viruses.
• This drug is not a substitute for early vaccination on an annual basis as recommended by the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices.
• Prophylaxis should be considered for the 2 to 4 week time period required to develop an antibody response; study durations ranged from 11 days to 6 weeks; safety and efficacy have not been demonstrated for longer than 6 weeks.

Use: For the prophylaxis of illness caused by various strains of influenza A virus.

Usual Pediatric Dose for Influenza A

17 years or older:
100 mg orally twice a day for 7 days

Comments:

• The adamantanes (amantadine and rimantadine) are not recommended for use in the US at this time because of widespread antiviral resistance in circulating influenza A viruses.
• Therapy should be initiated as soon as possible, preferably within 48 hours after onset of signs and symptoms of influenza A infection; therapy should be continued for approximately 7 days from the initial onset of symptoms.

Use: For the treatment of illness caused by various strains of influenza A virus in patients 17 years or older.

Usual Pediatric Dose for Influenza Prophylaxis

1 to 9 years: 5 mg/kg (up to 150 mg) orally once a day
Maximum dose: 150 mg/day

10 years or older: 100 mg orally twice a day

Comments:

• The adamantanes (amantadine and rimantadine) are not recommended for use in the US at this time because of widespread antiviral resistance in circulating influenza A viruses.
• This drug is not a substitute for early vaccination on an annual basis as recommended by the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices.
• Prophylaxis should be considered for the 2 to 4 week time period required to develop an antibody response; study durations ranged from 5 to 6 weeks; safety and efficacy have not been demonstrated for longer than 6 weeks.

Use: For the prophylaxis of illness caused by various strains of influenza A virus in children 1 year or older.

Renal Dose Adjustments

Severe renal dysfunction (CrCl 5 to 29 mL/min) or renal failure (CrCl 10 mL/min or less): 100 mg orally once a day

Liver Dose Adjustments

Severe liver dysfunction: 100 mg orally once a day

Dose Adjustments

Elderly nursing home patients: 100 mg orally once a day

Precautions

CONTRAINDICATIONS:

• Known hypersensitivity to drugs of adamantane class including rimantadine and amantadine

Safety and efficacy for the treatment of symptomatic influenza have not been established in patients younger than 16 years.
Safety and efficacy for the prophylaxis of influenza have not been established in patients younger than 1 year.

Consult WARNINGS section for additional precautions.

Dialysis

100 mg orally once a day

Comments:

• Rimantadine is not removed by hemodialysis.

Other Comments

On the basis of available antiviral testing results, the Centers for Disease Control and Prevention (CDC) recommend that rimantadine not be used for treatment or prophylaxis of currently circulating influenza A virus strains; oseltamivir or zanamivir recommended if antiviral medication needed.

Administration advice:

• Therapy should begin within 48 hours of onset of signs/symptoms of influenza A infection; efficacy of rimantadine started after 48 hours not known. Therapy should be continued for about 7 days from initial onset of symptoms.
• Prophylaxis is generally started when an outbreak of influenza A is documented and continued until it is over, if necessary, or until an immune response is provided by immunization (2 to 4 weeks after vaccination).
• Compounded rimantadine oral suspension preferred for patients who have difficulty swallowing tablets.

Reconstitution/preparation techniques:

• During emergency situations only: For patients who have difficulty swallowing tablets or where lower doses are needed, an oral suspension (10 mg/mL) may be prepared from rimantadine 100 mg tablets using Ora-Sweet(R); the manufacturer's product information should be consulted for compounding procedures.

General:

• Annual vaccination is preferred method for prophylaxis against influenza A; rimantadine should not be considered a substitute.
• To minimize the entrapment of air, the compounded oral suspension should be shaken gently before each use.
• Any remaining suspension must be discarded after completion of therapy or after the labeled expiration date. The compounded oral suspension is stable for 14 days at room temperature; therefore, the maximum amount to be dispensed should not exceed a 14 day supply.

Monitoring:

• General: For side effects in patients with liver or renal dysfunction