Rimantadine
Rimantadine is an antiviral medicine used to prevent and treat illness caused by influenza A (a type of flu virus).
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
How we combine label and product data →
Patient information guide — a plain-language walkthrough of Rimantadine, written from its FDA label.
What Rimantadine is used for
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Rimantadine is an antiviral used for influenza A. The tablets are labeled for:
- Preventing influenza A in adults (17 and older).
- Preventing influenza A in children 1 to 16 years old.
- Treating influenza A illness in adults (17 and older), ideally started within 48 hours of symptoms.
It is not approved to treat flu in children 16 and younger.
How Rimantadine works
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Rimantadine seems to block an early step in how influenza A multiplies, possibly the “uncoating” of the virus inside your cells. A virus protein called M2 plays a key role in whether the virus responds to the drug. It is active against influenza A subtypes H1N1, H2N2 and H3N2, but has little or no activity against influenza B.
Flu viruses can develop resistance, and resistant viruses can spread and still cause typical flu. Resistance to rimantadine also means resistance to amantadine, a related drug.
Rimantadine dosage
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Rimantadine tablets are taken by mouth. Adults usually take them twice a day. Children 1 to 9 years old usually take them once a day based on weight, while children 10 and older use the adult schedule.
- Treatment is started as soon as possible after symptoms begin and lasts about 7 days.
- Prevention is used during flu outbreaks; safety and effectiveness are not shown beyond 6 weeks.
- After a flu shot during an outbreak, prevention may be considered for the 2 to 4 weeks it takes for protection to build.
- A once-daily lower amount is recommended for older nursing home residents and people with severe liver or kidney problems.
Follow your prescriber and the label.
Dosing details from the FDA-approved label
From the Rimantadine prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Prophylaxis in adults (17 years and older)
- 100 mg twice a day
- Study durations ranged from 11 days to 6 weeks in adult and elderly patients
- In severe hepatic dysfunction, severe renal impairment (CrCl 5 to 29 mL/min) or renal failure (CrCl ≤ 10 mL/min) and in elderly nursing home patients, a dose reduction to 100 mg daily is recommended; monitor patients with hepatic or renal impairment for adverse effects
- Prophylaxis in children 1 year to 9 years of age
- 5 mg/kg once a day
- Maximum: 150 mg
- Study duration ranged from 5 weeks to 6 weeks in pediatric subjects; oral suspension may be compounded from tablets for children and patients with difficulty swallowing tablets
- Prophylaxis in children 10 years of age or older (up to 16 years)
- Use the adult dose (100 mg twice a day)
- Study duration ranged from 5 weeks to 6 weeks in pediatric subjects
- Prophylaxis in children birth to 11 months
- Safety and efficacy have not been established in patients younger than 1 year of age
- No dose given
- Treatment of influenza A in adults (17 years and older)
- 100 mg twice a day for 7 days
- Initiate as soon as possible, preferably within 48 hours after onset of signs and symptoms
- Continue for approximately seven days from initial onset of symptoms
- In severe hepatic dysfunction, severe renal impairment (CrCl 5 to 29 mL/min) or renal failure (CrCl ≤ 10 mL/min) and elderly nursing home patients, a dose reduction to 100 mg daily is recommended; monitor patients with hepatic or renal impairment for adverse effects
- Treatment in children (16 years of age and younger)
- Not indicated for treatment of influenza in pediatric patients 16 years or younger
- No dose given
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION For Prophylaxis in Adults and Children Adults (17 years and older) The recommended adult dose of rimantadine hydrochloride is 100 mg twice a day. Study durations ranged from 11 days to 6 weeks in adult and elderly patients. In patients with severe hepatic dysfunction, severe renal impairment (CrCl 5 to 29 mL/min) or renal failure (CrCl ≤ 10 mL/min) and in elderly nursing home patients, a dose reduction to 100 mg daily is recommended. Because of the potential for accumulation of rimantadine metabolites during multiple dosing, patients with hepatic or renal impairment should be monitored for adverse effects. Children (1 year to 16 years of age) Study duration ranged from 5 weeks to 6 weeks in pediatric subjects. In children 1 year to 9 years of age, rimantadine hydrochloride should be administered once a day, at a dose of 5 mg/kg but not exceeding 150 mg. For children 10 years of age or older, use the adult dose. (see Directions for Compounding of an Oral Suspension from Rimantadine Hydrochloride Tablets to prepare an oral suspension for administration to children and patients with difficulty swallowing tablets). Children (Birth to 11 months) The safety and efficacy of rimantadine hydrochloride for prophylaxis of influenza in pediatric patients younger than 1 year of age have not been established. For Treatment in Adults Adults (17 years and older) The recommended adult dose of rimantadine hydrochloride is 100 mg twice a day for 7 days. In patients with severe hepatic dysfunction, severe renal impairment (CrCl 5 to 29 mL/min) or renal failure (CrCl ≤ 10 mL/min) and elderly nursing home patients, a dose reduction to 100 mg daily is recommended. Because of the potential for accumulation of rimantadine metabolites during multiple dosing, patients with hepatic or renal impairment should be monitored for adverse effects. Rimantadine hydrochloride 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 seven days from the initial onset of symptoms. Children (16 years of age and younger) Rimantadine hydrochloride is not indicated for treatment of influenza in pediatric patients 16 years or younger.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Rimantadine side effects
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Common side effects
- Trouble sleeping (insomnia)
- Dizziness
- Nausea
- Vomiting
- Loss of appetite
- Dry mouth
- Stomach pain
- Nervousness, tiredness or weakness
When to get medical help
- Call your doctor if you notice confusion, hallucinations (seeing or hearing things that aren’t there), tremor or seizures.
- Get help right away for fainting, a pounding or irregular heartbeat, or trouble breathing.
- Call your doctor if you develop a rash or ringing in the ears.
- Tell your doctor about new or worsening depression or agitation.
- Seek emergency help if you think you took too much.
Most side effects involve the stomach and nervous system.
- Trouble sleeping
- Dizziness
- Headache
- Nervousness
- Tiredness or weakness
- Nausea and vomiting
- Loss of appetite
- Dry mouth
- Stomach pain
Less often, people report trouble concentrating, unsteadiness, sleepiness, depression, rash or ringing in the ears. Rarely, hallucinations, confusion, seizures, fainting or heart rhythm and breathing problems were reported. Call your doctor about these. Side effects increase at higher-than-recommended doses.
Rimantadine warnings and precautions
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- Resistance: flu viruses change, and resistance could make rimantadine less effective.
- Not a vaccine substitute: it does not replace the yearly flu shot.
- Liver or kidney problems: the drug and its by-products can build up, so you may need a lower amount and monitoring for side effects.
- Older adults: more nervous system and stomach side effects were seen, including in people over 65.
Rimantadine interactions
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Few interactions were described, but one matters:
- Live nasal spray flu vaccine: rimantadine may interfere with it. Wait 48 hours after stopping rimantadine before the vaccine, and wait 2 weeks after the vaccine before starting rimantadine, unless your doctor says otherwise.
- Acetaminophen and aspirin: lowered rimantadine levels by about 10%.
- Cimetidine: no significant effect on rimantadine levels.
Interactions listed in the FDA-approved label
From the Rimantadine prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Acetaminophen: Co-administration with acetaminophen (650 mg four times daily) reduced the peak concentration and AUC values for rimantadine by approximately 11%.
- Aspirin: Peak plasma concentrations and AUC of rimantadine were reduced approximately 10% in the presence of aspirin (650 mg, four times daily).
- Cimetidine: With steady-state cimetidine (300 mg four times a day) there were no statistically significant differences in rimantadine Cmax or AUC.
- Live Attenuated Influenza Vaccine (LAIV): Concurrent use has not been evaluated, but there is potential interference between the products because antiviral drugs may inhibit replication of live vaccine virus. Do not give live attenuated intranasal influenza vaccine until 48 hours after cessation of rimantadine; do not give rimantadine until two weeks after the vaccine unless medically indicated.
Read the label’s full interactions text
Drug Interactions Acetaminophen: Rimantadine hydrochloride, 100 mg, was given twice daily for 13 days to 12 healthy volunteers. On day 11, acetaminophen (650 mg four times daily) was started and continued for 8 days. The pharmacokinetics of rimantadine were assessed on days 11 and 13. Co-administration with acetaminophen reduced the peak concentration and AUC values for rimantadine by approximately 11%. Aspirin: Rimantadine hydrochloride, 100 mg, was given twice daily for 13 days to 12 healthy volunteers. On day 11, aspirin (650 mg, four times daily) was started and continued for 8 days. The pharmacokinetics of rimantadine were assessed on days 11 and 13. Peak plasma concentrations and AUC of rimantadine were reduced approximately 10% in the presence of aspirin. Cimetidine: When a single 100 mg dose of rimantadine hydrochloride was administered with steady-state cimetidine (300 mg four times a day), there were no statistically significant differences in rimantadine C max or AUC between rimantadine hydrochloride alone and rimantadine hydrochloride in the presence of cimetdine. Live Attenuated Influenza Vaccine (LAIV): The concurrent use of rimantadine hydrochloride with live attenuated intranasal influenza vaccine has not been evaluated. However, because of potential interference between these products, the live attenuated intranasal influenza vaccine should not be administered until 48 hours after cessation of rimantadine hydrochloride and rimantadine hydrochloride should not be administered until two weeks after the administration of live attenuated intranasal influenza vaccine unless medically indicated. The concern about potential interference arises principally from the potential for antiviral drugs to inhibit replication of live vaccine virus.
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Rimantadine
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- Do not use if you are allergic to rimantadine, amantadine or similar adamantane drugs.
- Tell your prescriber about liver or kidney disease.
- Older adults, especially in nursing homes, are usually given a lower daily amount.
- Not studied for prevention in children under 1 year old.
- Not for treating flu in children 16 and younger.
Rimantadine overdose
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For rimantadine overdose, supportive care is given. With the related drug amantadine, overdoses caused agitation, hallucinations, irregular heartbeat and death. Seek emergency help or call poison control right away if you take too much.
What Rimantadine does in the body
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Rimantadine reduces the multiplication of influenza A viruses in cell studies. When started within 48 hours of symptoms, it shortened the length of fever and body-wide symptoms. It does not appear to interfere with the response to the inactivated flu vaccine.
How your body processes Rimantadine
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Rimantadine is absorbed after you swallow it and reaches its highest blood level in about 6 hours. Its half-life is about 25 hours in healthy adults, and longer in older adults. It is heavily broken down by the liver, and less than 25% leaves in urine unchanged.
Drug levels rise in severe liver disease, severe kidney impairment and in elderly nursing home residents. Dialysis does not remove it.
How to store Rimantadine
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Store at 20° to 25°C (68° to 77°F) .
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Rimantadine
17 supplements and herbal products have documented interactions with Rimantadine in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 7
- Minor · 9
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Rimantadine: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Rimantadine — the kind of thing our pharmacy team would talk through with you at the counter.
What is rimantadine for?
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When should I start it if I already have flu symptoms?
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Does it replace my flu shot?
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What side effects should I expect?
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Do I need a different amount if I’m older or have kidney or liver problems?
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Can my child take it?
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Is Rimantadine available over the counter?
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When was Rimantadine first available?
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Who makes Rimantadine?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Rimantadine on HelloPharmacist
Rimantadine forms and strengths (how it comes)
Rimantadine is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Rimantadine Hydrochloride tablets are used to prevent influenza A in adults and children 1 to 16 years old.
- Rimantadine Hydrochloride tablets are used to treat influenza A illness in adults 17 and older.
- Rimantadine Hydrochloride tablets are taken by mouth.
- For flu treatment, Rimantadine Hydrochloride tablets should be started as soon as possible, ideally within 48 hours of symptoms, for about 7 days.
- For people who have trouble swallowing tablets, a pharmacist may prepare a liquid from Rimantadine Hydrochloride tablets in emergency situations or when lower doses are needed.
Rimantadine on the U.S. market: products, makers and brands
How Rimantadine appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
2 companies list 3 Rimantadine product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 1993. Brand names on the directory include Flumadine, Flumadine Syrup; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Compare Rimantadine products
A representative set of FDA-listed product records for Rimantadine — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 100 mg | Oral | Amneal Pharmaceuticals of New York LLC × 2 listings | ANDA | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | Olpha AS | BULK INGREDIENT FOR HUMAN PRESCRIPTION COMPOUNDING | View NDC → |
Showing 3 of 3 products — FDA National Drug Code Directory. See every product, package size and price: browse all 3 Rimantadine NDCs →
Rimantadine side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Rimantadine — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Rimantadine in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Rimantadine FDA approval history
How Rimantadine went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Rimantadine recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Rimantadine recalls since July 2021.
✅No Rimantadine recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 9386 2 dose forms · 2 strengths
-
Dose form (SCDF) Oral Solution RxCUI 756780No current FDA listingClinical drug / strength (SCD) hydrochloride 10 MG/MLRxCUI 856600 -
Dose form (SCDF) Oral Tablet RxCUI 373789In current FDA listingsClinical drug / strength (SCD) hydrochloride 100 MGRxCUI 856605
Look up RxCUI 9386 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Rimantadine supply and shortage status
Whether Rimantadine is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Rimantadine brand names
Rimantadine is sold under 2 brand names in the FDA directory — Flumadine, Flumadine Syrup. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Rimantadine: manufacturers and labelers
2 companies list Rimantadine products with the FDA. By number of product records, the largest are Amneal Pharmaceuticals of New York LLC, Olpha AS. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Rimantadine drug class (RxNorm)
Rimantadine belongs to the Influenza A M2 Protein Inhibitor class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Rimantadine page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Amneal Pharmaceuticals of New York LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →