You have been advised by the American Heart Association and the American College of Cardiology that if you have systolic blood pressure of 130 or higher and/or diastolic blood pressure of 80 or higher that you have hypertension. That means at least half of all adults in the United States now have high blood pressure. The chances are good that many of them will be prescribed thiazide diuretics as first line therapy. But what are hydrochlorothiazide side effects? And are they serious?
Hydrochlorothiazide (HCT or HCTZ): One of The Most Popular BP Drugs in the World:
One of the most popular blood pressure pills in the world has been linked to skin cancer. More than 20 million Americans take hydrochlorothiazide or HCTZ every day. It is found in dozens of combination blood pressure pills and has been perceived as an extremely safe choice for controlling hypertension.
A new study from Denmark, however, suggests that this thiazide diuretic is associated with squamous cell carcinoma (Journal of the American Academy of Dermatology, April, 2018). This type of skin cancer is linked to excessive sun exposure. HCTZ sensitizes the skin to ultraviolet radiation from the sun.
The study included 80,000 Danish citizens with non-melanoma skin cancer. Those who took the highest dose of hydrochlorothiazide for the most years were seven times more likely to develop squamous cell carcinoma than people who took no HCTZ. The scientists looked at other blood pressure medications and did not find any similar associations.
Squamous Cell Carcinoma:
When most people think about common cancers they immediately imagine breast cancer, lung cancer, prostate cancer and colon and rectum cancer. According to the American Cancer Association, the projections are that in 2017 there will be:
253,000 cases of breast cancer
222,000 cases of lung cancer
161,000 cases of prostate cancer
135,000 cases of colorectal cancer
It comes as a total shock to learn that the American Academy of Dermatology estimates that:
“Squamous cell carcinoma (SCC) is a common skin cancer in humans. About 700,000 new cases of this skin cancer are diagnosed in the United States each year.”
Most people do not worry much about skin cancer unless there is a diagnosis of melanoma. They assume that squamous cell carcinoma is not that big a deal. Although squamous cell carcinoma (SCC) is often successfully treated with surgery, it can occasionally be lethal. An article in JAMA Dermatology (May, 2013) noted:
“Cutaneous squamous cell carcinoma [CSCC] carries a low but significant risk of metastasis and death. In this study, patients with CSCC had a 3.7% risk of metastasis and 2.1% risk of disease-specific death.”
Hydrochlorothiazide Side Effects and Squamous Cell Carcinoma:
The Danish researchers have been concerned about the link between hydrochlorothiazide and squamous cell carcinoma for some time. They reported in the Journal of Internal Medicine (Oct. 2017) that “Hydrochlorothiazide use is strongly associated with an increased risk of lip cancer.” They described it as a “clear dose-response effect.” In other words, the greater the exposure to the drug the more serious the risk.
In their new publication, they note:
“Recently, we reported a strong association between use of the diuretic hydrochlorothiazide (HCTZ) and squamous cell carcinoma (SCC) of the lip. We found a clear dose-response pattern, with an estimated 7-fold increased risk of SCC lip cancer with cumulative use of ≥100,000 mg HCTZ. Our findings were in line with the results of previous studies from the United States (US) and the recent classification of HCTZ as ‘possibly carcinogenic to humans’ (Group 2B) by the International Agency for Research on Cancer (IARC). As HCTZ is among the most widely used drugs in the US and western Europe, a carcinogenic effect of HCTZ would have a considerable impact on public health.”
The authors conclude:
“In conclusion, given the considerable use of HCTZ worldwide and the morbidity associated with NMSC [non-melanoma skin cancer], a causal association between HCTZ use and NMSC risk would have significant public health implications. The use of HCTZ should be carefully considered, as several other antihypertensive agents with similar indications and efficiency are available, but without known associations with skin cancer.”
The People’s Pharmacy Perspective:
Hydrochlorothiazide is considered very safe by most physicians. This diuretic is often the first line treatment for high blood pressure. What is especially concerning is that many patients don’t even realize they are taking HCTZ. That’s because it is frequently added to another drug such as an ACE inhibitor a beta blocker or an ARB. For a list of drugs containing hydrochlorothiazide, please visit this link.
Other Hydrochlorothiazide Side Effects:
There are a surprising number of hydrochlorothiazide side effects that often go unmentioned. They include electrolyte imbalances, elevated blood sugar, raised uric acid levels, muscle cramps, irregular heart rhythms, dizziness, elevated cholesterol levels, and dry eyes.
To learn more about hydrochlorothiazide side effects, visit this article:
Share your own story about hydrochlorothiazide side effects in the comment section below. If you have done well with this drug we would like to hear from you as well.