Apomorphine (DB00714): A Comprehensive Monograph on its Pharmacology, Clinical Utility, and Safety Profile

Executive Summary

Apomorphine is a potent, non-ergoline, non-selective dopamine agonist that occupies a specialized niche in the management of advanced Parkinson's disease (PD). Its primary, well-established clinical role is the acute, intermittent treatment of hypomobility, or "off" episodes, which are debilitating motor fluctuations that occur despite optimized oral therapy.[1] The name "Apomorphine" is a historical artifact derived from its synthesis from morphine; however, it is crucial to recognize that the molecule possesses no opioid receptor activity and is devoid of narcotic properties, a point of potential clinical confusion that requires clarification.[3]

The clinical utility of apomorphine is defined by a challenging pharmacokinetic profile, characterized by poor oral bioavailability and a very short elimination half-life.[3] These limitations have been the primary drivers of pharmaceutical innovation, leading to the development of non-oral formulations designed to bypass first-pass metabolism and provide clinically meaningful drug exposure. These include a subcutaneous injection (Apokyn) for rapid rescue, a sublingual film (Kynmobi) as a non-invasive alternative, and, most recently, a continuous subcutaneous infusion device (Onapgo) for stable, long-term motor control.[5]