May increase the serum conc of ACE inhibitors. Hypotensive effect may be enhanced w/ alfuzosin, other antihypertensives, barbiturates, dapoxetine, diazoxide, herb (hypotensive properties), hydrochlorothiazide, MAOIs, pentoxifylline, prostacyclin analogues. May enhance hyperkalemia/hypotensive/nephrotoxic effect w/ aliskiren. May enhance hypotensive effect of amifostine, obinutuzumab, risperidone, rituximab. May enhance hypertensive effect w/ brimonidine (topical). May enhance hyperkalemic/hypotensive effect w/ canagliflozin. May enhance arrhythmogenic effect of ciprofloxacin. May enhance hyperkalemic effect w/ cyclosporine, eplerenone, heparin (including low molecular wt heparin), nicorandil, K salts, K-sparing diuretics, tolvaptan, trimethoprim. May increase serum conc of eltrombopag, lithium, teriflunomide. May diminish antihypertensive effect w/ herbs (hypertensive properties), methylphenidate, & yohimbine. May enhance adverse/toxic effects of other hypotensive agents, NSAIDs. May enhance orthostatic hypotensive effect of levodopa. May enhance hypotensive/orthostatic hypotensive effect w/ MAIOs. May enhance antihypertensive effect w/ phosphodiesterase 5 inhibitors. May enhance nephrotoxic effect of Na phosphates.