Drug Interaction Report

MONITOR: The concomitant use of corticosteroids and agents that deplete potassium (e.g., potassium-wasting diuretics, amphotericin B, cation exchange resins) may result in increased risk of hypokalemia. Corticosteroids can produce hypokalemia and other electrolyte disturbances via mineralocorticoid effects, the degree of which varies with the agent (from most to least potent: fludrocortisone - cortisone/hydrocortisone - prednisolone/prednisone - other glucocorticoids) and route of administration (i.e. systemic vs. local). However, large systemic doses of any corticosteroid can demonstrate these effects, particularly if given for longer than brief periods. When used pharmacologically, adrenocorticotropic agents such as corticotropin have similar mineralocorticoid activities as cortisone and hydrocortisone.

MANAGEMENT: Patients receiving potassium-depleting agents with corticosteroids should be monitored closely for development of hypokalemia, particularly if fludrocortisone or large doses of another corticosteroid or adrenocorticotropic agent is given. Potassium supplementation may be necessary. Patients should be advised to notify their physician if they experience signs of electrolyte disturbances such as weakness, lethargy, and muscle pains or cramps.

MONITOR: Many psychotherapeutic and CNS-active agents (e.g., anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, alcohol, muscle relaxants) exhibit hypotensive effects, especially during initiation of therapy and dose escalation. Coadministration with antihypertensives and other hypotensive agents, in particular vasodilators and alpha-blockers, may result in additive effects on blood pressure and orthostasis.

MANAGEMENT: Caution and close monitoring for development of hypotension is advised during coadministration of these agents. Some authorities recommend avoiding alcohol in patients receiving vasodilating antihypertensive drugs. Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients should also avoid driving or operating hazardous machinery until they know how the medications affect them.

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.