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Angry Doctor Insists HCTZ Is Safe!

Over 10 million people take hydrochlorothiazide for blood pressure. A doctor says HCTZ is safe! He's mad at us for describing side effects.

Hydrochlorothiazide (HCTZ) is one of the most prescribed drugs in the US. It is a diuretic that helps lower blood pressure. At last count, over 10 million people swallow this pill daily. But HCTZ is also combined with blood pressure (BP) drugs like lisinopril, losartan, valsartan, olmesartan, bisoprolol and triamterene. That adds another 7 million people. A lot of people believe HCTZ is safe, and yet there are side effects. One physician took us to task about the connection between hydrochlorothiazide and elevated blood sugar.

MD Is Mad as Hell! He Says HCTZ Is Safe:

Q. I am a retired physician who was also a pharmacist. I believe your answer about hydrochlorothiazide (HCTZ) and diabetes is misleading and may potentially scare patients away from a beneficial medication.

HCTZ may increase blood sugar a few points, but it does not cause a person to become diabetic. According to several studies, the benefits of lowering blood pressure outweigh the slight increase in blood sugar elevation. Please don’t make a physician’s job more difficult.

A. Thank you for pointing out the important role that diuretics like HCTZ play in the treatment of high blood pressure. Let’s revisit our previous Q&A:

Q. I took hydrochlorothiazide for ten years to treat blood pressure. As a result, I developed diabetes, for which the doctor prescribed some pills I don’t like.

When I saw my new doctor last spring, I provided a list of vitamins and food that I eat in place of pills to control diabetes, blood pressure, and high cholesterol. He read the list and then he looked at me and said: “If this is what you are doing keep it up! All of your numbers are low!”

Mostly it was just common everyday food such as garlic, turmeric, cinnamon and vinegar water. I am just about through with diabetes. I think people should know about these options.

Prior Answer:

A. Hydrochlorothiazide and similar blood pressure diuretics can raise blood sugar, as you learned through experience. Generally, doctors prescribe medications to control diabetes, though diet and exercise can be very helpful.

We’re impressed you have done so well, and it makes sense for you to have your doctor monitor your progress. There are many non-drug ways to control blood sugar and you are using several of them. Both turmeric and cinnamon have research that supports their effectiveness.

HCTZ Is Safe…But There Are Side Effects

Meta-analyses show that, on average, the increase in blood glucose associated with HCTZ is small (Journal of Clinical Hypertension, April 2016; Journal of General Internal Medicine, June 2020).

Most people probably have no difficulties with this effect. For a few individuals, however, it might become worrisome. Some people are more susceptible to drug side effects than others.

It is always important to warn people about potential adverse reactions so that they can be alert for complications. It would be sad if someone developed diabetes because of a drug reaction and did not realize it could be corrected just by changing medicine.

We urge all readers to work with their physicians to balance benefits and risks appropriately. The person who contacted us about HCTZ raising blood sugar was able to control both their blood pressure and diabetes with nondrug approaches.

Other Complications from HCTZ:

Because doctors prescribe hydrochlorothiazide so frequently, they may take it for granted. We agree with this doctor that HCTZ is safe, but here are some potential adverse reactions patients may not be warned about:

Hydrochlorothiazide and Gout:

When uric acid levels go too high, a person can experience gout. The pain in joints can be excruciating. People should always be warned that diuretics like HCTZ can raise uric acid levels. Here is a link about just such a reaction:

Hydrochlorothiazide (HCTZ) Side Effects, Complications and Gout!

This article also mentions that HCTZ and similar diuretics can lead to electrolyte imbalances:

• Low potassium levels (hypokalemia)
• Low sodium levels (hyponatremia)
• Low magnesium levels (hypomagnesemia)
• High calcium levels (hypercalcemia)
• Low chloride levels (hypochloremia)
• Low zinc levels

It is worth a minute of your time to review some other common HCTZ side Effects at this link.

HCTZ Is Safe…But What About Skin Cancer?

We suspect that most physicians have never heard about a connection between hydrochlorothiazide and skin cancer. It is controversial. Here is a link to an article about HCTZ and squamous cell carcinoma. The diuretic may make the skin more sensitive to ultraviolet radiation from the sun.

Here is an article in the journal Evidence-Based Dentistry (March, 2022).

The authors conclude:

“The risk of NMSC [non-melanoma skin cancer] and lip cancer in a UK population is increased with cumulative high-dose HCTZ exposure. It is therefore important for dentists to note as it may increase suspicion of lesions in patients taking these medications.”

The association was confirmed in the European Journal of Clinical Pharmacology (June, 2022).

Purpose: The aim of this study is to investigate the association between hydrochlorothiazide (HCTZ) use and the risk of cutaneous [skin] and lip squamous cell carcinoma development.

Results: A total of 2181 published studies referring to the theme were identified, from which six were included in this systematic review… This meta-analysis demonstrated a chance of developing cutaneous and lip squamous cell carcinoma in any region of the body in hydrochlorothiazide users of 1.76-fold higher than in non-users. In addition, a risk factor of 1.80 higher of cutaneous squamous cell carcinoma in the head and neck region was observed in HCTZ users.

Conclusions: Our results confirm the association between the use of hydrochlorothiazide and the cutaneous and lip squamous cell carcinoma development.”

We offer information on the pros and cons of BP medications in our eGuide to Blood Pressure Solutions. This online resource may be found under the Health eGuides tab. It also discusses a number of non-drug ways to help control high blood pressure.

Please share your own experience with blood pressure medications in the comment section below.

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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.”.
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  • Carney K & Cousins M, "Does hydrochlorothiazide increase the incidence of skin, lip and oral cancer in a UK population?" Evidence-Based Dentistry, March, 2022. DOI: 10.1038/s41432-022-0255-x
  • Andradem A.C. de M, et al, "Hydrochlorothiazide use is associated with the risk of cutaneous and lip squamous cell carcinoma: A systematic review and meta-analysis," European Journal of Clinical Pharmacology, June, 2022, DOI: 10.1007/s00228-022-03299-x
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