Oral meptazinol--United Kingdom experience.

An oral formulation of meptazinol has been developed and marketed in the United Kingdom. The 200 mg tablet has a potency similar to dextropropoxyphene 32.5 mg/paracetamol 325 mg or pentazocine 50 mg. Nausea is the major side effect and constipation and dysphoria are virtually absent. Though a variable first pass metabolism restricts its potential for use in severe pain, oral meptazinol provides effective analgesia in mild or moderate pain.