Loop diuretics Captopril

The antihypertensive effects of captopril can be antagonized (reduced) by (A) Angiotensin II receptor blockers Loop diuretics NSAIDs... 

The combination of captopril or other ACE inhibitors with loop or thiazide diuretics is normally safe and effective, but first dose hypotension (dizziness, lightheadedness, fainting) can occur, particularly if the dose of diuretic is high, and often in association with various predisposing conditions. Renal impairment, and even acute renal failure, have been reported. Diuretic-induced hy-pokalaemia may still occur when ACE inhibitors are used with these potassium-depleting diuretics. 

The risk of ACE inhibitor-induced renal impairment in patients with or without renovascular disease can be potentiated by diuretics. " In an analysis of 74 patients who had been treated with captopril or lisinopril, reversible acute renal failure was more coimnon in those who were also treated with a diuretic (furosemide and/or hydrochlorothiazide) than those who were not (11 of 33 patients compared with 1 of 41 patients). Similarly, in a prescription-event monitoring study, enalapril was associated with raised creatinine or urea in 75 patients and it was thought to have contributed to the deterioration in renal function and subsequent deaths in 10 of these patients. However, 9 of these 10 were also receiving loop or thiazide diuretics, sometimes in high doses. Retrospective analysis of a controlled study in patients with hypertensive nephrosclerosis identified 8 of 34 patients who developed reversible renal impairment when treated with enalapril and various other antihypertensives including a diuretic (furosemide or hydrochlorothiazide). In contrast, 23 patients treated with placebo and various other antihypertensives did not develop renal impairment. Subsequently, enalapril was tolerated by 7 of the 8 patients without deterioration in renal function and 6 of these patients later received diuretics. One patient was again treated with enalapril with recurrence of renal impairment, but discontinuation of the diuretics (furosemide, hydrochlorothiazide, and triamterene) led to an improvement in renal function despite the continuation of enalapril. ... 

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