Narrow therapeutic index drugs

Although most medications have a wide margin of safety, a few "high-alert drugs" bear a heightened risk of causing injury when they are misused. Medications with a "narrow therapeutic index" - a very small therapeutic dose range about or below which could cause significant toxicity or sub-therapeutic levels—also bear an increased risk of causing injury when they are misused. Although errors may or may not be more common with these drugs than with others, their consequences may be more devastating. Examples of "high-alert drugs" or "narrow therapeutic index drugs" include monoamine oxidase (MAO) inhibitors, warfarin, oral hypoglycaemic agents, insulin, digoxin, opiate narcoties and many cancer drugs.

(Cohen MR, Kilo CM. High-alert medications: Safe guarding against errors. In: Cohen MR. Ed. Medication Errors. AmPharm Assoc Washington DC 1999.)