Selective MAO-B inhibitor Pregnancy: UK SPC section 4.6: available safety data in pregnancy and lactation are insufficient to justify use; as a precautionary measure it is preferable to avoid selegiline in pregnancy, and it should not be used during breast-feeding.

Selegiline hydrochloride

Brand names: Eldepryl

Selegiline hydrochloride is a monoamine oxidase-B inhibitor used as an adjunct in Parkinson's disease, often with levodopa, to prolong dopaminergic effect.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 10 mg daily

Route: Oral

Frequency: Once daily in the morning, or in two divided doses of 5 mg taken at breakfast and lunch

UK SPC (Eldepryl 10 mg Tablets) section 4.2: '10 mg daily either alone or as an adjunct to levodopa or levodopa/peripheral decarboxylase inhibitor.' When selegiline is added to a levodopa regimen it is possible to reduce the levodopa dosage by an average of 10-30%; reduction of the levodopa dose should be gradual, in steps of 10% every 3 to 4 days. Section 4.2 states that no dosage adjustment is required for patients with renal or hepatic impairment. Section 4.4 notes that the precise dose at which selegiline becomes a non-selective inhibitor of all MAO has not been determined, but that with doses higher than 10 mg/day there is a theoretical risk of hypertension after ingestion of tyramine-rich food. Paediatrics: the UK SPC gives no paediatric dose; the US label records that 'the effects of selegiline hydrochloride in children have not been evaluated' — verify any paediatric use against a children's formulary. The US label (selegiline hydrochloride tablets) gives the same total: 10 mg per day as divided doses of 5 mg each taken at breakfast and lunch, adding that higher doses give no additional benefit and should ordinarily be avoided.

Dose adjustments

Renal

UK SPC section 4.2: no dosage adjustment is required for patients with renal or hepatic impairment. Section 4.4 nonetheless advises that selegiline should be used with caution in severe liver or kidney dysfunction.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity (including severe dizziness or hypotension) to selegiline or any of the excipients
Patients receiving serotonin agonists (e.g. sumatriptan, naratriptan, zolmitriptan, rizatriptan)
Concomitant use with pethidine and other opioids
Patients being treated with antidepressants, including MAO inhibitors, tricyclic antidepressants, SNRIs (e.g. venlafaxine) and SSRIs (e.g. citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline)
Other monoamine oxidase inhibitors, e.g. linezolid
Combination with sympathomimetics
Active duodenal or gastric ulcer
Extrapyramidal disorders not related to dopamine deficiency
In combination with levodopa: severe cardiovascular disease, arterial hypertension, hyperthyroidism, phaeochromocytoma, narrow-angle glaucoma, prostatic adenoma with residual urine, tachycardia, arrhythmias, severe angina pectoris, psychoses, advanced dementia and thyrotoxicosis

Side effects

Stomatitis (very common)
Sleeping disorders, confusion, hallucinations, depression (common)
Abnormal movements such as dyskinesias, akinesia and bradykinesia, dizziness, headache, impaired balance, tremor (common)
Hypotension and hypertension, bradycardia (common)
Nausea, constipation, diarrhoea, mouth ulceration (common)

Interactions

Serotonin agonists (triptans), pethidine and other opioids, MAOIs (including linezolid), tricyclic antidepressants, SNRIs and SSRIs — contraindicated combinations (section 4.3)
Buprenorphine/opioids — concomitant administration may result in serotonin syndrome, a potentially life-threatening condition (section 4.4)
Medicines that inhibit MAO-A, or non-selective MAO inhibitors — can cause hypotensive reactions (section 4.4)
Sympathomimetics — should not be used in combination (section 4.3); the US label reports a case of hypertensive crisis with selegiline plus ephedrine
CNS depressants used for general anaesthesia — MAO inhibitors including selegiline may potentiate their effects; transient respiratory and cardiovascular depression, hypotension and coma have been reported (section 4.4)
Levodopa — selegiline potentiates its effect, so levodopa side effects may be emphasised unless the levodopa dose is reduced (section 4.8)

Clinical monograph

How it works

At usual doses it selectively and irreversibly inhibits monoamine oxidase type B, reducing the breakdown of dopamine in the brain.

Prescribing in practice

Combination with serotonergic agents such as SSRIs, SNRIs, tricyclics or pethidine risks serotonin toxicity, so these combinations should be avoided and washout periods observed.
Adding selegiline to levodopa may potentiate dopaminergic adverse effects such as dyskinesia, postural hypotension and confusion, which may require levodopa dose reduction.
MAO-B selectivity can diminish at higher doses, raising the theoretical risk of tyramine-related hypertensive reactions.

Monitoring

Monitor blood pressure, motor response and for confusion or hallucinations, especially during initiation and dose changes.

Counselling the patient

Report dizziness on standing, vivid dreams, confusion or involuntary movements.
Tell any prescriber you take selegiline before starting antidepressants or strong painkillers.
Do not stop suddenly without advice.

Evidence & guidelines

MAO-B inhibitors are established adjuncts in Parkinson's disease management, supported by NICE guidance on motor symptom control.

Reference: NICE NG71; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways