Morphine question

In chemical terms, diamorphine is the diacetylated ester of morphine. The practical significance of this is that it easily crosses the blood-brain barrier to produce it's much-abused euphoric effect. This euphoric effect also has a justified clinical benefit since it can be very effective in relieving patient anxiety in severe trauma situations, heart attacks and terminal illness.

Apart from the obvious analgesic and anti-anxiety effects, its use in heart attacks, acute heart failure and pulmonary oedema stems from its peripheral vasodilatory action which reduces myocardial oxygen demand and offloads the failing heart by reducing cardiac pre-load. Morphine will also achieve the same effect.

In terms of common-or-garden analgesia or post-operative pain control, there is little to justify the use of diamorph over morphine. It produces the same analgesic effect at roughly half the dose of morphine but this is of no relevance in such scenarios. There are still a few maverick anaesthetists who claim diamorphine is a "better" painkiller but I imagine the evidence is probably outdated if not non-existent. As a pure analgesic only, we tend to use it occassionally for patients in sickle-cell crises who are either morphine-intolerant or have not responded to morphine or fentanyl previously.