Adverse drug reactions and interactions in a nursing home.

Adverse drug reactions (ADRs) and interactions were the third most common drug-related problem (DRP) found in a two-year study of DRPs in a 72-bed nursing home. Neurotropic drugs followed by antihypertensives, potassium supplements, potassium-sparing diuretics, diuretics, digoxin and nonsteroidal antiinflammatory drugs antacid interactions, and antiinfective rashes accounted for 88 percent (143 of 161) of the adverse reactions and interactions. A number of adverse reactions and interactions. A number of adverse drug reactions and interactions were preventable, in that careful attention to the patient's complete history, problem list, and relative-to-absolute contraindications to drugs should have resulted in drug changes/discontinuances in at least 61 percent (98 of 161) cases. An adverse reaction rate of 9.3 percent (161 of 1,728) drug regimen reviews was found. Adverse drug reaction is defined as any undesirable effect of drug therapy. Drug-drug interaction is a combination of drugs that may result in a beneficial or detrimental effect. For purposes of this study, only drug interactions of a detrimental nature were considered. The prior Legal Briefs column (May/June '85) in this series dealt with drug contra-indications, or the presence of some condition or historical fact in the patient that indicates that a drug should probably-to-absolutely not be used in the patient. This current column deals with the development of undesirable consequences when the prescriber, pharmacist, and those administering the drug may not have been aware of the historical events or predisposing conditions and adverse events occurred.