beta-blockers. Drug interactions of clinical significance

The clinician prescribing beta-blockers for his or her patients is faced with an often difficult situation. There are many beta-blockers, each with its own pharmacological profile. Patients are often taking multiple medications, thus increasing the risk of both anticipated and unexpected drug interactions. Reports of drug interactions are frequently anecdotal. The prescriber may not be aware of the patient's other medications or lifestyle habits. Pharmacokinetic and pharmacodynamic drug interactions involving beta-blockers are documented in the literature, but these studies often examine small numbers of patients. For these reasons, it is difficult for the practitioner to distill guidelines for the administration of beta-blockers in conjunction with other medication. In general, beta-blockers are well tolerated, and symptomatic drug interactions are relatively infrequent. It is incumbent upon the clinical practitioner to have knowledge of his or her patient's drug profile and to be aware of the various drug interactions as well as each patient's unique pathophysiological profile when prescribing any medication, including beta-blockers. beta-Blockers may interact with a large number of commonly prescribed drugs, including antihypertensive and antianginal drugs, inotropic agents, anti-arrhythmics, NSAIDs, psychotropic drugs, anti-ulcer medications, anaesthetics, HMG-CoA reductase inhibitors, warfarin, oral hypoglycaemics and rifampicin (rifampin).