Dosing & Uses
Dosage Forms & Strengths
Influenza A Virus
- 100 mg PO q12hr
- 100 mg PO q12hr preferably within 48 hours after onset of signs and symptoms of influenza A infection
Dosage Forms & Strengths
Severe renal (CrCl <10 mL/min) or liver impairment: Administer qDay
Serious - Use Alternative
Significant - Monitor Closely
Difficulty in concentrating (<2%)
Abdominal pain (1%)
Hypersensitivity to amantadine, rimantadine or any drug component
CDC advises against use for treatment or prophylaxis of influenza in the US during the 2008-09 influenza season
Caution in patients with history of seizures; discontinue if seizures occur
Avoid use in patients with psychosis (active or uncontrolled)
Caution in renal impairment
Pregnancy & Lactation
Pregnancy Category: C
Lactation: enters breast milk
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Mechanism of Action
Inhibits viral replication of three subtypes of influenza A (H1N1, H2N2, H3N2) early in the viral replicative cycle. Has no activity against influenza B virus.
Onset of action: antiviral activity: no data exist establishing a correlation between plasma concentration & antiviral effect
Absorption: tablet and syrup formulations are equally absorbed
Metabolism: Hepatic (extensive)
Protein binding: 40% (primarily to albumin)
Half-life: 25.4 hr; prolonged in elderly as well as severe renal and hepatic impairment
Peak Plasma Time: 6 hr
Excretion: Urine (<25% as unchanged drug)
Clearance: Hemodialysis does not contribute to clearance
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.
|1||This drug is available at the lowest co-pay. Most commonly, these are generic drugs.|
|2||This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.|
|3||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.|
|4||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|5||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|6||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|NC||NOT COVERED – Drugs that are not covered by the plan.|
Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.