Studies of Drugs Given Before Anaesthesia Xix: The Opiates

Abstract

Using Ridit analysis, a comparison was made of the overall effects of what are generally considered to be equianalgesic doses of sixteen opiates, with respect to their desired and toxic effects when given as premedication to a standard population. Four mixtures of opiates, the non-opiate diazepam and saline were also included in the analysis. Results with all individual drugs have been previously reported in detail. Under the conditions of this study, pethidine 100 mg, papaveretum 20 mg and even morphine 10 mg are too toxic to warrant their present popularity. More attention should be paid to the use of levorphanol 2 mg, diamorphine 5 mg, methadone 10 mg and oxycodone 10 mg for premedication. These findings may be modified by the concomitant use of atropine or hyoscine. Papaveretum-hyoscine fully justifies its popularity, but its greater efficacy can be explained by its high morphine content and the action of hyoscine. Under appropriate conditions diazepam may be superior to any of the opiates for use in premedication.

Controlled Comparison of the Efficacy of Fourteen Preparations in the Relief of Postoperative Pain

“…The commonly used doses of these drugs placed in rank order with respect to incidence of successful postoperative pain relief according to the criteria described above are given in Table IV Morrison et al, 1969;Dundee et al, 1970). Before discussing individual drugs it is worth considering the rank order of efficacy of the analgesics studied (Table IV) compared with a similar grading of efficacy based solely on the patient's estimation of pain relief (Table V).…”

Controlled Comparison of the Efficacy of Fourteen Preparations in the Relief of Postoperative Pain

“…It must also, of course, be remembered that analgesic potency represents only one aspect of a drug's performance;J the incidence and severity of side effects being at least equally important in determining its clinical value, and these have already been reported in respect of the drugs included in this trial Morrison et al, 1969;Dundee et al, 1970). Before discussing individual drugs it is worth considering the rank order of efficacy of the analgesics studied (Table IV) compared with a similar grading of efficacy based solely on the patient's estimation of pain relief (Table V).…”

Pentazocine

“…The incidence and severity of side-effects of the drugs tested in this trial have been fully discussed in other papers Morrison et al, 1969) and their relative merits, based on overall effects, discussed by Dundee et al (1970) . Side-effects of pentazocine are discussed in section 6.…”