Abstract

Most drugs which are ordinarily given by mouth cause no gastric symptoms and are well absorbed whether taken on a full or an empty stomach. However, for some commonly used drugs the time of administration in relation to meals is important either because it affects their therapeutic efficacy or their irritant action on the stomach. Little information or advice on this is available from official books or from manufacturers. The rate of gastric emptying varies widely depending on the nature of the meal, and especially its fat content. This article cannot define the optimum conditions for the oral administration of all drugs, but lists those drugs whose therapeutic efficacy or liability to cause gastric disturbance are markedly influenced by food intake. Patients can be given specific advice about such drugs. Where relevant information is lacking the patient can often achieve optimal results by comparing the effects obtained when he takes the drug at different times in relation to food. The consistent use of instructions is likely to reduce the variability of patients’ responses to a drug.