Sildenafil Diuretics

The manufacturers report that in population pharmacokinetic analysis, there was no effect on sildenafil pharmacokinetics in those taking ACE inhibitors, calcium-channel blockers and tMazide and related diuretics whereas the AUC of the less potent active metabolite of sildenafil is increased by 62% by loop and potassium-sparing diuretics and by 102% by non-selective beta blockers, although these changes were not considered clinically relevant. ... 

Treatment recommendations cannot be derived firom such limited experience. Individual cases have been treated with calcium channel blockers and diuretics (26), nifedipine and diuretics (27), or sildenafil (27). Nifedipine decreased echo estimated RV systolic pressures from 90 to 84 mmHg (27). Median survival for all reported cases was 157 days (range 19-1036 days). Calcium channel blockers (28) and digoxin (29) avidly bind amyloid fibrils, producing locally toxic drug-myocardial interaction. Calcium channel blockers can worsen CHF in patients with amyloid cardiomyopathy and should be used cautiously (30). 

---