Subcutaneous injection of apomorphine hydrochloride (Apokyn), a potent dopamine agonist, is effective for the temporary relief (“rescue”) of off-periods of akinesia in patients on optimized dop-aminergic therapy. It is rapidly taken up in the blood and then the brain, leading to clinical benefit that begins within about 10 min-utes of injection and persists for up to 2 hours. The optimal dose is identified by administering increasing test doses until adequate benefit is achieved or a maximum of 10 mg is reached. Most patients require a dose of 3–6 mg, and this should be given no more than about three times daily.
Nausea is often troublesome, especially at the initiation of apomorphine treatment; accordingly, pretreatment with the anti-emetic trimethobenzamide (300 mg three times daily) for 3 days is recommended before apomorphine is introduced and is then continued for at least 1 month, if not indefinitely. Other adverse effects include dyskinesias, drowsiness, chest pain, sweating, hypotension, and bruising at the injection site. Apomorphine should be prescribed only by physicians familiar with its potential complications and interactions.