Sublingual doses range from 200-400mcg 8 hourly. Both have been used to provide postoperative analgesia by intermittent, continuous and PCA techniques. They are alleged to have a lower abuse potential than conventional opioid agents. Side effects and toxicity Opioid analgesics share many side effects though the degree may vary between agents. The most common include nausea, vomiting, constipation and drowsiness.
Larger doses produce respiratory depression and hypotension.
The specific antidote naloxone is indicated if there is coma or very slow respiration. Because of its short action, repeated injections of 200 - 400mcg intravenously may be necessary. Alternatively, it may be given by continuous intravenous infusion, the rate of administration being adjusted according to response.