OBJECT DRUGS

• Trimethoprim (Bactrim, Septra)

PRECIPITANT DRUGS

Angiotensin Receptor Blockers:

• Azilsartan (Edarbi)
• Candesartan (Atacand)
• Eprosartan (Teveten)
• Irbesartan (Avapro)
• Losartan (Cozaar)
• Olmesartan (Benicar)
• Telmisartan (Micardis)
• Valsartan (Diovan)

Comment:

Trimethoprim alone often produces modest increases in serum potassium, and hyperkalemia can occur when it is combined with other drugs that increase potassium such as angiotensin receptor blockers (ARBs). Hospitalizations for hyperkalemia are substantially higher in patients on ARBs who take trimethoprim versus amoxicillin, for example. The risk may be increased in the presence of one or more predisposing factors such as significant renal impairment, severe diabetes, potassium supplements, high potassium diet, advanced age or additional drugs that can increase potassium such as ACE inhibitors, drospirenone (Yasmin), heparins, nonselective beta-blockers, NSAIDs, COX-2 inhibitors, cyclosporine, tacrolimus, succinylcholine, pentamidine, and potassium-containing salt substitutes.

Class 2: Use Only if Benefit Felt to Outweigh Risk

• Use Alternative: If possible use an antibiotic other than trimethoprim.
• Monitor: If trimethoprim is used in patients on ARBs, monitor serum potassium concentrations, especially in patients with predisposing factors such as renal disease, diabetes, and advanced age.