Rimantadine
Anti-influenza agents
Anti-influenza agents
An oral adamantane that blocks the M2 channel of influenza A. It is no longer recommended because most circulating viruses are resistant.
Quick facts
- Group
- Anti-influenza agents
- Target
- Influenza A M2 proton channel
- Used for
- Historically prevention and treatment
- Key effects
- Upset stomach and loss of appetite · Nervousness
- Monitor
- Mental status and sleep · Liver function
- ATC
- J05AC02
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows rimantadine inside the pore of the influenza A M2 proton channel.
Rimantadine, like amantadine, blocks the M2 protein of influenza A, a proton channel in the viral envelope. Protons entering through M2 inside the endosome let the viral ribonucleoprotein separate from the matrix protein (uncoating); blocking it stops this early step. It has no activity against influenza B, which lacks M2. A single mutation in the M2 transmembrane region gives high-level resistance, and it appears quickly during treatment.
- M2 lets protons into the virion in the endosome
- Rimantadine plugs the M2 channel
- The viral genome is not released (no uncoating)
- One M2 mutation abolishes the effect
Indications
- Historically prevention and treatment of influenza A; not recommended now because of high resistance Influenza (flu) →
Adverse effects
Common
- Upset stomach and loss of appetite
- Nervousness, light-headedness and difficulty concentrating
- Insomnia
- Tiredness
Contraindications
- Hypersensitivity to rimantadine
Key interactions
- Aspirin and paracetamol (acetaminophen)
- Listed as interacting; reviewed before combining
- Antihistamines, psychotropic or anticholinergic drugs
- Adamantane central nervous system effects may increase, especially in older adults
What is monitored
- Mental status and sleep
- Seizure control in people with epilepsy
- Liver function
Administration and safety
- Oral, with food if it upsets the stomach
- Do not confuse with amantadine, the related drug also used in Parkinson disease
Pregnancy and breastfeeding
No adequate human data are available; it is not used in pregnancy now that better options exist.
Nursing care
- Check local resistance data: adamantanes are not used for current influenza
- Ask about epilepsy, liver disease and kidney disease
- Teach to report confusion, mood change or yellow skin
- Remind that vaccination remains the main prevention
Pharmacokinetics
- Absorption
- Oral
- Metabolism
- Extensively metabolised in the liver before excretion
- Elimination
- Mainly as metabolites in the urine; elimination depends on liver function
Test yourself
Think of the answer, then tap the question to see it.
Which protein does rimantadine block?
The M2 proton channel of influenza A.
Why does rimantadine not work against influenza B?
Influenza B has no M2 protein.
Why are adamantanes not recommended for influenza today?
Most circulating influenza A viruses carry M2 mutations that make them resistant.
Connections
← Back to the class: Anti-influenza agents
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Rimantadine: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); Influenza Antiviral Medications: Summary for Clinicians (Centers for Disease Control and Prevention, 2025); Influenza A M2 proton channel wild type TM domain bound to R-rimantadine (RCSB Protein Data Bank, 2020).
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Representative model, for educational purposes only.