Case: 82 year old nursing home resident lady has been admitted to ICU with GI bleed, since she started taking aspirin on someone's advise. Otherwise, past medical history is significant only for hypertension for which she is taking lisinopril. While in ICU, she noticed to have "dirty urine" and has been started on Bactrim (sulfamethoxazole and trimethoprim). You get called as nurse noticed change in EKG rhythm. You ordered 12 leag EKG which is as follows. What is your diagnosis?
Answer: Bactrim Induced Hyperkalemia
Hyperkalemia due to Bactrim (sulfamethoxazole and trimethoprim) affects elderly patients frequently even with standard oral dosages, despite normal serum creatinine level. Concurrent angiotensin-converting enzyme inhibitor therapy increase the risk of hyperkalemia. Moreover, this patient may have pRBC transfusion which itself carries a load of potassium. In symptomatic patients, standard therapy for hyperkalemia is required otherwise withdrawal of drug is sufficient.
Reference: click to get abstract
Trimethoprim-induced hyperkalemia: An analysis of reported cases - Gerontology. 1999 Jul-Aug;45(4):209-12
