Can physicians warn patients of potential side effects without fear of causing those side effects?

When initiating treatment, it has been shown that only one quarter of the physicians discuss potential side effects with patients. There are several possible reasons, but, in particular, many physicians are concerned that the power of suggestion may lead some patients to experience an increase in side effects if they are fully informed. Accordingly, this study was designed to determine whether providing patients with information about potential side effects of new medications increases the reported incidence of those side effects.

All clinic patients are randomly assigned to one of four firms. Two firms served as the intervention group and two served as control groups. All patients receiving new prescriptions for the angiotensin-converting enzyme inhibitors, trimethoprim/sulfamethoxazole, or nonsteroidal anti-inflammatory drugs were recruited. Patients without telephones were excluded. Intervention patients received verbal instructions and a handout describing the name, purpose, dose, and three most common side effects of the drug. Control patients received usual discharge instructions. Patients were interviewed 14 to 21 days later using a standardized questionnaire.

There was no difference in incidence of targeted side effects for specific medications between the study groups (38% vs 37%). Study groups were similar with regard to age, sex, financial status, and type of medication prescribed.

Informing patients of potential side effects prior to starting a new medication does not lead to an increased incidence of those side effects. This should not be a reason for physicians to avoid warning patients of potential side effects.