Expanded PBS Listing for Apomorphine

Apomorphine was added to the Pharmaceutical Benefits Scheme (PBS) General Schedule on 1 October 2020. Apomorphine is indicated for the treatment of Parkinson disease in patients who have experienced severely disabling motor fluctuations that are refractory to conventional therapy.

Apomorphine is a short-acting dopamine agonist with similar efficacy to levodopa, but with a shorter onset and duration of effect. Apomorphine freely crosses the blood-brain barrier, achieving a concentration in the brain up to eight times greater than the plasma. Intermittent dosing provides rapid and effective relief of “off” periods. However, a continuous subcutaneous infusion may be considered for patients whose overall control remains inadequate or for patients who require many injections throughout the day. A recent double-blind trial found that continuous apomorphine infusion reduced daily “off” time by 2.47 hours at week 12, compared to 0.58 hours in the placebo group.

Gastrointestinal adverse effects, such as nausea and vomiting, are commonly reported. Pre-treatment with domperidone, a peripherally acting dopamine antagonist, should begin at least 48 to 72 hours before apomorphine therapy is initiated. Tolerance to gastrointestinal adverse effects develops rapidly, and the domperidone dose can be gradually reduced over several weeks to the lowest effective dose.