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Dopamine Agonist / NMDA Antagonist (Anti-Parkinsonian)

Amantadine

Brand names: Lysovir

Amantadine is used in Parkinson's disease, particularly to reduce levodopa-induced dyskinesia, and also has antiviral activity. It is renally excreted.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION The dose of amantadine hydrochloride capsules may need reduction in patients with congestive heart failure, peripheral edema, orthostatic hypotension, or impaired renal function (see Dosage for Impaired Renal Function ).

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-06-06. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It is thought to enhance dopaminergic transmission and acts as an NMDA-receptor antagonist, which contributes to its antidyskinetic effect.

Prescribing in practice

  • Reduce the dose in renal impairment, as the drug is renally excreted and accumulation increases the risk of toxicity.
  • It can cause confusion, hallucinations and ankle swelling, particularly in older people, and may produce livedo reticularis (a mottled skin discolouration).
  • Do not stop abruptly, as this can acutely worsen Parkinsonian symptoms; because it can cause insomnia, avoid late-in-the-day dosing.

Monitoring

Monitor renal function and adjust the dose accordingly; review motor benefit, mental state (confusion, hallucinations), ankle oedema, sleep and skin changes.

Counselling the patient

  • Report new confusion, hallucinations or marked ankle swelling.
  • Do not stop the medicine suddenly, as your Parkinson's symptoms can flare.
  • Take the dose earlier in the day to reduce the chance of difficulty sleeping.

Evidence & guidelines

Recognised option for levodopa-induced dyskinesia in Parkinson's disease (NICE NG71).

Reference: NICE NG71 Parkinson's Disease; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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