Salty broth for salicylate poisoning? Adequacy of overdose management advice in the 2001 Compendium of Pharmaceuticals and Specialties.

BACKGROUND

The Compendium of Pharmaceuticals and Specialties (CPS) is a collection of monographs written by pharmaceutical companies and published by the Canadian Pharmacists Association. The CPS is widely available and is consulted frequently by Canadian physicians. We examined overdose management advice contained in the CPS to see whether it reflects current standards.

METHODS

We restricted our review to 10 classes of medication for which an overdose is frequently fatal: acetaminophen, beta-blockers, calcium-channel blockers, digoxin, lithium, opioids, salicylates, tricyclic antidepressants, theophylline and valproic acid. A panel of 3 toxicologists arrived at a consensus on indicated, contraindicated and futile interventions for each of these classes of drug. Monographs were then rated for their inclusion of essential interventions as excellent (listed all interventions and unique supportive care issues and gave correct and complete indications), good (listed the key interventions and gave correct and complete indications), fair (listed the key indications but failed to give proper indications) or poor (failed to list the key interventions). Monographs were also rated on how well they warned against contraindicated interventions as excellent (did not advocate any futile or contraindicated treatments and warned against contraindicated treatments), good (did not advocate any futile or contraindicated treatments), fair (did not advocate any contraindicated treatments but did list some simple futile treatments) or poor (advocated contraindicated or complicated futile treatments, such as unnecessary hemodialysis). We also considered whether the monograph would allow a clinician to manage an overdose, whether it served to refresh one's memory and whether it was simply misleading or dangerous.

RESULTS

We reviewed 119 monographs, of which 25 (21%) were adequate to allow a clinician to manage an overdose. Another 25 monographs were not adequate to allow a clinician to manage an overdose but would serve to refresh the memory regarding key management points. Sixty monographs (50%) contained misleading or dangerous advice. Nine monographs (8%) did not fall into any of these categories. In terms of listing essential interventions, 61 monographs (51%) were poor, 35 (29%) were fair, 22 (18%) were good, and 1 (1%) was excellent. For warning against contraindicated interventions, 57 monographs (48%) were poor, 9 (8%) were fair, 51 (43%) were good, and 2 (2%) were excellent.

INTERPRETATION

Overdose management advice in the CPS is inadequate in most cases and is misleading or dangerous in half of the monographs examined. These sections should be omitted or rewritten to reflect current standards of care. Physicians should refer to authoritative sources (e.g., current toxicology texts, computerized databases or local poison control centres) for poisoning management advice.