Go Ad-Free
logoThe People's Perspective on Medicine

Potassium Plus Blood Pressure Pills A Deadly Mix

Combining potassium supplements and a salt substitute with the blood pressure drug enalapril set this reader up for a deadly potassium interaction.

Do you know how your diet relates to your medication? Prescribers don’t always mention dietary precautions when they hand out a prescription. But often they should discuss this to avoid a potential problem. We get especially excited about a potassium interaction with an ACE inhibitor.

Enalapril and a Potassium Interaction:

Q. My pharmacist said I could have killed myself if I kept taking potassium with my blood pressure medicine. My new doctor switched me to enalapril and didn’t mention any precautions.

Before this I was on hydrochlorothiazide and potassium supplements. It’s lucky my pharmacist noticed I had changed blood pressure prescriptions when I went to have the potassium refilled.

I have also used Lite Salt or NoSalt for years to reduce my sodium intake. Do I need to stop using the salt substitute as well?

A. Potassium-based salt substitutes like the ones you have been using can be a good way of cutting back on sodium and getting extra potassium. But in combination with medicines such as Vasotec (enalapril), Capoten (captopril), Lotensin (benazepril), Aceon (perindopril), Accupril (quinapril), Altace (ramipril), Mavic (trandolapril), or Zestril (lisinopril), salt substitutes and potassium supplements could be disastrous. Too much potassium can cause fatal heart rhythms.

Overlooking the Potassium Interaction Was a Medical Mistake:

This was an example of a serious medical mistake. The new physician clearly did not take time to review all the prior medications that had been prescribed and notice the potassium interaction. People take potassium supplements to compensate for the depletion of potassium brought on by diuretics like hydrochlorothiazide (HCTZ) or furosemide (Lasix). But when the prescription was changed to the ACE inhibitor enalapril, the doctor should have been far more careful to check the medical records and ask about salt substitutes. Fortunately, the pharmacist saved the day (and potentially your life).

Such mistakes are far more common than most people realize. That’s why we wrote Top Screwups Doctors Make and How to Avoid Them. It offers hundreds of questions to ask and tips to prevent this kind of potentially lethal error. In particular, there is information on common mistakes made with ACE inhibitors, diabetes drugs, hypothyroidism and heartburn. Here’s a link to the People’s Pharmacy Store if you would like a copy.

Other Medications That Upset Potassium Balance:

In people whose kidneys don’t work efficiently, an ACE inhibitor drug all by itself could lead to high potassium (Turgutalp, Renal Failure, Oct. 2016). So can NSAID pain relievers such as diclofenac, ibuprofen, meloxicam or naproxen. When doctors prescribe spironolactone or an ARB blood pressure pill such as losartan, they should monitor potassium to make sure it doesn’t get too high.

Potassium isn’t the only potential problem. Vitamin and mineral interactions with some medicines can be life threatening. We are sending you our Guide to Drug and Nutrient Interactions. It tells which prescription drugs can provoke nutritional deficits and alerts you to problems that may occur if you take supplements with your medications.

Revised 3/13/17

Rate this article
star-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-emptystar-fullstar-empty
4.1- 64 ratings
About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
Tired of the ads on our website?

Now you can browse our website completely ad-free for just $5 / month. Stay up to date on breaking health news and support our work without the distraction of advertisements.

Browse our website ad-free
Join over 150,000 Subscribers at The People's Pharmacy

We're empowering you to make wise decisions about your own health, by providing you with essential health information about both medical and alternative treatment options.