Drug Interaction Report

MONITOR: Due to their gastrointestinal pharmacologic effects, somatostatin analogs (e.g., octreotide, lanreotide) may variously affect the absorption of dietary nutrients and concomitantly administered oral medications. Somatostatin analogs have been shown to prolong gastrointestinal transit time and inhibit intestinal absorption of some nutrients such as fat. Clinical data are limited, however. In case reports, octreotide has been reported to reduce the relative bioavailability of cyclosporine. Transplant rejection and significant reductions in cyclosporine levels, sometimes to undetectable levels, have been reported in association with the interaction. Vitamin K absorption was not affected when concomitantly administered with lanreotide according to the manufacturer.

MANAGEMENT: Clinicians should be aware of the potential for altered absorption of concomitantly administered oral medications during treatment with somatostatin analogs. Blood levels and clinical response should be monitored, particularly for drugs that have a narrow therapeutic index, and the dosages adjusted as necessary.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.