MIMS is not a stand-alone resource

To the Editor: I was part of a review of the Therapeutic Goods Administration (TGA)-approved product information (PI) monographs contained in MIMS (Monthly index of medical specialties) annual with respect to their poisoning management advice.1 We looked at the 10 most common poisonings presenting to Westmead Hospital and another 15 clinically important poisonings as determined by two of the authors, and compared the poisoning management advice given in MIMS to a “gold standard” derived from a consensus of five pharmacological resources. For the 25 drugs examined, 14 monographs contained inaccurate information, one contained a recommendation for ineffective treatments, and 14 omitted specific treatments or antidotes. Many of these errors could delay or even prevent patients receiving currently accepted and effective therapies for life-threatening poisonings if MIMS were used as the primary resource.

The omission of sodium bicarbonate for ventricular conduction delay and hypotension in amitriptyline, quinine and thioridazine poisonings is particularly problematic. Ventricular conduction delay and hypotension is often refractory to other therapies, and delay in bicarbonate administration could result in avoidable deaths. The recommendation of sodium bicarbonate for ventricular conduction delay and hypotension was included in the TGA-approved monograph for amitriptyline in 1984, but was subsequently removed without qualification in 1990 and remains absent. Cyproheptadine, an important therapy for serotonin syndrome, is not included in the TGA-approved monograph for sertraline, and its delay could result in avoidable morbidity. Atropine for verapamil-induced bradycardia is a simple and intuitive therapy; however, its omission from the TGA-approved monograph could again result in avoidable morbidity and mortality.

We also found potentially dangerous treatments recommended in the TGA-approved monographs not covered by the consensus opinion. These included intravenous amphetamine or intramuscular ephedrine to counter the sedative effects of promethazine poisoning, administration of enteric-coated ammonium chloride tablets to increase urinary excretion in chloroquine poisoning, and forced osmotic diuresis using a urea or mannitol infusion for lithium poisoning. These treatments are out of the Dark Ages, and their use should be considered negligent.

Based on this and other reports in previous editions of the Journal, the TGA-approved PI monographs contain inaccurate, inadequate, out-of-date or potentially dangerous information relating to poisoning management advice, paediatric drug dosages,2 drug interactions,3 breastfeeding mothers,4 and various thyroid medications.5 How can we use MIMS for anything other than simple drug formulation information? Surely, to anyone who wishes to practise up-to-date, safe, evidence-based medicine, the answer must be that we cannot.

It is time for the TGA to take up its role as regulator and insist on updated and accurate PI monographs from the pharmaceutical companies.