Do any of the patient's medications, including Lisinopril and Potassium Chloride ER, have the potential to cause hyperkalemia?

Medications That Cause Hyperkalemia in This Patient

Yes, this patient is taking two medications that directly cause hyperkalemia: Lisinopril (an ACE inhibitor) and Potassium Chloride ER supplements. Additionally, Bumetanide (a loop diuretic) is being used only three times weekly, which provides insufficient kaliuresis to counteract the hyperkalemia risk from the other agents.

Primary Culprits

Lisinopril 2.5 mg Daily

• Lisinopril is an ACE inhibitor that impairs renal potassium excretion by blocking aldosterone production, making it one of the most common drug-related causes of hyperkalemia 1, 2, 3.
• The FDA label explicitly warns to "check serum potassium and creatinine periodically to monitor for hyperkalemia" with all ACE inhibitors 1, 3.
• In clinical trials, hyperkalemia (serum potassium >5.7 mEq/L) occurred in 2.2% of hypertensive patients and 4.8% of heart failure patients treated with lisinopril 3.
• The risk of hyperkalemia increases dramatically when ACE inhibitors are combined with potassium supplements, potassium-sparing diuretics, or used in patients with renal insufficiency 3.

Potassium Chloride ER 10 mEq Daily

• This patient is receiving exogenous potassium supplementation while simultaneously taking an ACE inhibitor—a dangerous combination explicitly warned against in guidelines 1, 2, 3.
• The order indication states "for hyperkalemia," which appears to be a prescribing error, as potassium supplements cause hyperkalemia, not treat it 2.
• Potassium supplements combined with ACE inhibitors create additive hyperkalemia risk and should be avoided unless there is documented refractory hypokalemia 3.

Aggravating Factor: Inadequate Diuretic Coverage

Bumetanide 0.5 mg Three Times Weekly

• Loop diuretics promote potassium excretion and can mitigate hyperkalemia risk from RAAS inhibitors, but this patient receives bumetanide only on Tuesday, Thursday, and Saturday 1.
• This intermittent dosing provides insufficient kaliuresis on the four days weekly when no diuretic is given, allowing potassium accumulation 1.
• Guidelines recommend considering loop or thiazide diuretics concurrently with RAAS inhibitors to reduce hyperkalemia risk, but this requires consistent daily dosing 2.

Medications That Do NOT Cause Hyperkalemia

The following medications on this list are not associated with hyperkalemia 4, 5:

• Milk of Magnesia, Bisacodyl, Senna-S, GlycoLax, Enema (laxatives/bowel regimen)
• Finasteride, Tamsulosin (BPH medications)
• Famotidine, Sucralfate (GI protection)
• Ajovy (Fremanezumab) (migraine prophylaxis)
• Hydralazine, Metoprolol (antihypertensives without potassium effects)
• Carbidopa-Levodopa (Parkinson's disease)
• Acetaminophen, Oxycodone (analgesics)
• Ventolin (Albuterol) (bronchodilator)
• Aspercreme Lidocaine Patch (topical analgesic)
• Nitroglycerin (antianginal)
• Meclizine (antivertigo)
• Escitalopram, Mirtazapine (antidepressants)
• Magnesium Oxide (magnesium supplement—does not affect potassium)
• Eliquis (Apixaban) (anticoagulant)

Critical Clinical Pitfall

The most dangerous aspect of this medication regimen is the combination of lisinopril with potassium chloride supplements 3. The FDA label for lisinopril explicitly states: "Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) can increase the risk of hyperkalemia. Therefore, if concomitant use of such agents is indicated, monitor the patient's serum potassium frequently" 3. This warning extends to potassium supplements 3.

Immediate Action Required:

• Discontinue potassium chloride ER immediately unless there is documented severe hypokalemia (<3.0 mEq/L) despite ACE inhibitor therapy 2, 3.
• Check serum potassium, creatinine, and estimated GFR urgently 1, 3.
• If hyperkalemia is present (K+ >5.5 mEq/L), consider temporarily holding lisinopril and reassessing renal function 3, 6.
• Consider increasing bumetanide frequency to daily dosing or adding a thiazide diuretic to promote potassium excretion 1, 2.
• Monitor serum potassium within 1 week of any medication adjustment 2.

Risk Stratification

This patient has multiple risk factors for severe hyperkalemia 7, 6, 8:

• ACE inhibitor use (lisinopril)
• Exogenous potassium supplementation
• Inadequate diuretic coverage (only 3 days/week)
• Possible underlying chronic kidney disease (suggested by need for bumetanide)
• Advanced age (common in patients on this medication profile)

The combination of these factors creates a high-risk scenario where severe hyperkalemia (K+ >6.5 mEq/L) requiring hospitalization can develop rapidly 7, 9.