Makindo Medical Notes

🧠 Selegiline is a selective MAO-B inhibitor used in Parkinson’s disease to boost central dopamine. ✅ Can help early PD symptoms and reduce “wearing-off” as adjunct to levodopa.
⚠️ Interactions matter (serotonergic drugs, opioids like pethidine) — always check the BNF.

About

• 📚 Always check the BNF for the latest prescribing advice, contraindications, and interaction details.
• 🧓 Used in Parkinson’s disease (PD) as monotherapy in early disease or as an adjunct to levodopa in fluctuating PD.
• 🎯 Core benefit: improves motor symptoms and may reduce end-of-dose deterioration (“wearing-off”).

Mode of Action

• 🧪 Inhibits monoamine oxidase-B (MAO-B) in the CNS → reduces dopamine breakdown.
• ⬆️ Increases synaptic dopamine availability → improves bradykinesia/rigidity and reduces off time in some patients.
• ⚙️ At standard doses it is relatively selective for dopamine metabolism; at higher doses selectivity decreases → wider monoamine effects and more interaction risk.

Indication / Dose

• 🧠 Parkinson’s disease: commonly 5 mg once daily for 2–4 weeks, then increase (if tolerated) to 10 mg daily (often in divided doses depending on formulation).
• 🌞 Dose in the morning (and midday if divided) to reduce insomnia and stimulant-type adverse effects.
• 🔁 If adding to levodopa, monitor for dopaminergic adverse effects (dyskinesia, hallucinations) and adjust levodopa if needed.

Interactions (high-yield)

• 💊 Levodopa: can enhance levodopa effects and side effects (dyskinesia, nausea, hallucinations). Consider reducing levodopa if troublesome.
• 🚫 Serotonergic drugs: risk of serotonin syndrome with SSRIs/SNRIs/TCAs and other serotonergic agents — check BNF for specific combinations and washout periods.
• 🚫 Opioids: particularly pethidine (meperidine) is contraindicated with MAO inhibitors (serious reactions). Check other opioids in BNF too.
• 🥫 Tyramine (“cheese effect”): generally minimal at standard MAO-B doses, but risk increases if higher doses reduce selectivity. Use BNF guidance if dose escalated.

Cautions

• 🧠 Neuropsychiatric: can worsen hallucinations, confusion, agitation (especially in older/frail patients or those with cognitive impairment).
• 🫀 Cardiovascular: caution in significant cardiovascular disease; monitor postural BP if symptomatic.
• 🧓 Falls risk: insomnia, postural hypotension, and confusion can increase falls risk—review if recurrent falls/delirium.

Contraindications

• ⛔ Refer to BNF for the full list.
• 🚫 Generally includes use with certain antidepressants/other MAO inhibitors and specific interacting medicines where severe reactions may occur.

Side Effects

• 🫀 Postural hypotension, palpitations/arrhythmias (uncommon but important if symptomatic).
• 🧠 Confusion, hallucinations, low mood, agitation.
• 😴 Insomnia (especially if taken later in the day).
• 🤢 GI upset: nausea, abdominal discomfort, constipation/diarrhoea.
• 🦴 Musculoskeletal aches (back/joint pain).

💡 Clinical Pearls

• ⏱️ Wearing-off: useful adjunct when patients “dip” before the next levodopa dose, but monitor for hallucinations and dyskinesia.
• 🌞 Morning dosing is a simple practical trick to reduce insomnia.
• 🧓 In older patients with confusion/hallucinations, consider whether selegiline is contributing before escalating dopaminergic therapy.
• 🧾 Always document counselling on interaction risk and ensure medicines reconciliation (especially antidepressants and opioids).

References

• BNF – Selegiline