Increases in digoxin peak plasma & trough conc. Significant increase in serum K w/ K-sparing diuretics (eg, spironolactone, eplerenone, triamterene or amiloride), K supplements, or K-containing salt substitutes. Reversible increases in serum lithium conc & toxicity. Reduced antihypertensive effect w/ NSAIDs (eg, acetylsalicylic acid at anti-inflammatory dosage regimens, COX-2 inhibitors & non-selective NSAIDs). Prior treatment w/ high-dose diuretics eg, furosemide (loop diuretic) & hydrochlorothiazide (thiazide diuretic) may result in vol depletion, & in risk of hypotension when initiating therapy. Higher frequency of adverse events w/ combined use of ACE inhibitors, angiotensin II receptor blockers, or aliskiren. Potentiated hypotensive effect w/ baclofen, amifostine. Aggravated orthostatic hypotension w/ alcohol, barbiturates, narcotics, or antidepressants. Reduced antihypertensive effect w/ systemic corticosteroids.