Diamorphine hydrochloride is a morphine derivative, with antitussive and analgesic properties used in the relief of cough and pain in terminal disease. It is contraindicated in other situations because of its addictive properties, and its tendency to cause sputum retention and ventilatory failure.
It is more potent than morphine, causes less nausea and hypotension, and its greater solubility allows effective doses to be given in smaller injected volumes - this property is useful in the emaciated patient.
Its capacity to produce euphoria gives it great potential for causing dependence. Tolerance develops: an increased dose is needed to produce pleasurable effects. It is usually bought in a brownish powder, and is smoked - "chasing the dragon" - or dissolved in acid for injection.