Anti-seizure and Parkinson medicines
Neurological medicines are generally continued preoperatively. Interruption can cause clinically important deterioration, making early reconciliation of the exact medicine and dose timing important.
Anti-seizure medicines
- Usual doses, including the morning dose, are generally continued with permitted water.
- When oral administration will be interrupted, an appropriate route or alternative can be planned with the relevant specialist. Several agents have intravenous formulations, for example levetiracetam, lacosamide, valproate and phenytoin/fosphenytoin.
- Enzyme-inducing anti-seizure medicines may alter the metabolism of other drugs used perioperatively.
- An individual exception may be needed, for example when anticonvulsants are deliberately withheld for electroencephalographic mapping during epilepsy surgery.
Parkinson medicines
Parkinson medicines can be time-sensitive. Missed or delayed doses can cause rapid deterioration in mobility, swallowing and respiratory function. Abrupt withdrawal of dopaminergic therapy has been associated with a rare but serious syndrome resembling neuroleptic malignant syndrome.
- Early scheduling, where feasible, and an agreed medicine schedule may help avoid missed time-critical doses.
- When swallowing or oral intake is interrupted, an alternative route or regimen may be needed. Enteral administration or a transdermal dopamine agonist may be options with specialist and pharmacy input; formulations and dose conversions are not interchangeable.
- Dopamine-antagonist antiemetics and antipsychotics (for example metoclopramide, prochlorperazine, haloperidol and droperidol) can worsen parkinsonism and are generally avoided.
- MAO-B inhibitors have potential interactions with some opioids and sympathomimetics that require review.
- Deep brain stimulators require device-specific planning, including with electrosurgery.
Communication of the agreed perioperative schedule to the ward and anaesthesia team helps maintain continuity.