The hydrochloride salt form of alfentanil, an ultra short-acting, synthetic opioid agonist with analgesic and local anesthesia enhancing activity.
Alfentanil hydrochloride primarily binds to and stimulates the opiate receptors in the central nervous system (CNS), thereby mimicking the actions of endogenous opioids. Stimulation of the mu-subtype opioid receptor stimulates the exchange of GTP for GDP on the G-protein complex and subsequently inhibits adenylate cyclase. This results in a decrease in intracellular cAMP and leads to a reduction in the release of various neurotransmitters.
The analgesic effect of alfentanil is likely due to the actions of its metabolite morphine, which induces opening of G-protein-coupled inwardly rectifying potassium (GIRK) channels and blocks the opening of N-type voltage-gated calcium channels, thereby resulting in hyperpolarization and reduced neuronal excitability.
Alfentanil is an opioid analgesic with a rapid onset of action.
1. Analgesia for short procedures e.g. colonoscopy
2. Analgesia for palliative procedures e.g. percutaneous vertebroplasty
Dose: at 5 mcg/kg, alfentanyl provides analgesia for the conscious, but sedated patient. Based on patient response, doses higher than 5 mcg/kg may be needed. Elderly or debilitated patients may require lower doses.
Alfentanil should be administered only by persons specifically trained in the use of intravenous and general anesthetic agents and in the management of respiratory effects of potent opioids.