Pethidine compared with pethidine-naloxone administered during labour. A study of analgesic treatment by a sequential method.

In a restricted sequential trial in healthy parturient women, the pain relief from pethidine 100 mg and pethidine 100 mg combined with naloxone 0.4 mg was compared. Pethidine alone gave better relief. The incidence of minor side-effects was high with both treatments but dizziness was reduced slightly by naloxone. It was concluded that naloxone antagonized the analgesia without abolishing the side-effects of pethidine.