The People's Perspective on Medicine

Hydrochlorothiazide (HCTZ) Side Effects, Complications and Gout!

New blood pressure guidelines will likely translate to millions more taking diuretics. Do people know about hydrochlorothiazide (HCTZ) side effects?

We suspect that hydrochlorothiazide (HCTZ or HCT for short) is the most prescribed drug in America on a daily basis. HCTZ is taken regularly by over 20 million people. More than 115 million prescriptions are dispensed annually.

Many doctors believe that hydrochlorothiazide (HCTZ) side effects are mild and rare. Patients are not always warned about adverse drug reactions.

We think people need to know more about this widely prescribed diuretic and blood pressure medicine.

Hydrochlorothiazide (HCTZ) Side Effects:

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

Other Hydrochlorothiazide (HCTZ) Side Effects:

  • High blood sugar levels (increased risk of type 2 diabetes)
  • High uric acid levels (increased risk of gout)
  • Elevated blood fats & cholesterol
  • Low blood pressure (leading to dizziness, lightheadedness on standing, fainting)
  • Digestive upset (stomach ache, diarrhea)
  • Muscle cramps, muscle weakness
  • Dry eyes
  • Headache
  • Sensitivity to sunlight, sunburn, rash
  • Erectile dysfunction, impotence
  • Irregular heart rhythms
  • Severe skin reactions (requires immediate emergency attention), dangerous allergic reactions
  • Blood disorders
  • Liver or kidney problems

Zombified by Too Many Side Effects:

Most people zone out after seeing just a few of the many listed hydrochlorothiazide (HCTZ) side effects. They assume that such complications will never affect them. Our bulletin boards and comments would suggest otherwise. The only way to truly grasp the meaning of such hydrochlorothiazide (HCTZ) side effects is to read stories from real people.

Let’s start with just one of these adverse reactions: high uric acid levels aka hyperuricemia.

Gout and HCTZ:

Q. I was on HCTZ to control my blood pressure for more than ten years. I suffered through many episodes of gout before I discovered that HCTZ raises uric acid levels.

I discussed this with my Internist, who said he could put me on allopurinol or take me off the HCTZ. I chose the latter, and my gout episodes have greatly diminished.

A. Gout is an excruciating inflammation of one or more joints linked to high uric acid levels. Diuretics like HCTZ (hydrochlorothiazide) can indeed raise uric acid levels. Such medicines are often prescribed to lower blood pressure.

Other readers have also experienced gout after taking HCTZ:

Tony in Florida says:

“I took HCTZ for about 15 years to lower my High BP. Soon after I started taking it, I started getting episodes of gout. Belatedly, I finally put the pieces together that HCTZ was a major contributor to my gout.

Blood Sugar Elevations and Diabetes:

We got spanked a few years ago by an outraged physician. He was furious because we wrote that diuretics like HCTZ could raise blood sugar and sometimes trigger type 2 diabetes. He considered our answer to a reader’s question “thoroughly irresponsible.”

You can read the whole story at this link:

Do Common Medicines Trigger Diabetes?

We’re not sure why this doctor was so upset. The FDA requires manufacturers of thiazide diuretics like HCTZ to state in the official prescribing information that:

“In diabetic patients dosage adjustments of insulin or oral hypoglycemic [diabetes] agents may be required. Hyperglycemia [diabetes] may occur with thiazide
 diuretics. Thus latent diabetes mellitus may become manifest during thiazide therapy.”

Reports from Readers:

Chuck says:

“I have been on HCTZ for 14 years. When I started my blood sugar was completely normal, but shortly after I went into the pre-diabetic range.

“Fasting blood glucose [FBG] was in the 105 to 115 range for more than 12 years, then 18 months ago my physician doubled my HCTZ dosage from 12.5mg to 25mg, and 12 months ago I was diagnosed with diabetes (FBG of 151).

“The kicker is that not one of these physicians ever informed me that there was a risk that HCTZ could cause an increase in blood sugar, and after it became full blown diabetes not one has suggested a change in my blood pressure medication.

“I feel it is the responsibility of the prescribing physician to discuss with me all of the potential side effects, and we will make the decision together. In my case several physicians felt “they knew best” and decided for me. This is unethical, but unfortunately seems to be the norm for some in the medical community.”

Brian added this:

“What a surprise I have been have been struggling with blood sugar levels myself. I also take hydrochlorothazide). In addition, I was suffering foot pain, even though the test for gout was negative my Dr suggested Indomethacin. This website provided information about problems HCTZ can cause. What a relief to know more about side effects of this medicine.”

Angela also reported early problems with HCTZ:

“I’m taking HCTZ for high blood pressure. I’m 78 and pretty healthy and have been on the pill since 5/07. Because I come from a diabetic family, I always have my glucose checked with my cholesterol. This month, for the first time, my glucose was 113; high for me and worrisome.”

HCTZ and Cholesterol:

Muriel in Durham, North Carolina shared this story:

“I was disparaged by my primary doctor over side effects of HCTZ. My cholesterol began to rise with no great changes in my eating habits and despite my planned weight loss.

“When I mentioned that this was one of the side effects of HCTZ listed on the packaging and that I had read up on it on the internet, the doctor flew into something of a mini rage. I was also experiencing dizziness. I reduced my cholesterol by taking fish oil and lecithin.”

Hydrochlorothiazide (HCTZ) Side Effects & Electrolyte Imbalances:

Even if people are warned about mineral imbalances with thiazide diuretics like HCTZ they may not appreciate how dangerous this can be.

Low Sodium and Potassium:

This past summer we received the following question from a concerned daughter:

“My elderly mother has been very conscientious about a low-salt diet. She never salts her food and is careful not to eat processed foods high in sodium. Despite this, her doctor diagnosed her with mild high blood pressure and put her on a diuretic called hydrochlorothiazide.

“Last week she got up in the middle of the night to go to the bathroom. She suddenly felt weak and collapsed. When the paramedics came in response to her call button, she was confused.
They took her to the hospital and discovered that her sodium and potassium levels were perilously low. Could her medicine be responsible for this scary episode?”

Diuretics like HCTZ can deplete the body of critical minerals. That includes potassium, sodium, magnesium and zinc. When these electrolytes get out of whack it can be very dangerous.

Liz in Raleign, NC dodged a bullet with her diuretic-induced hyponatremia:

“I was in my neighbor’s yard around dusk to check on his cat. I fell on something and hit my head, ending up in the trauma intensive care unit for four days. I needed four staples in my head to close the cut.

“I had limited memory before I fell and no memory at all for about three days while in the hospital. The diagnosis: low sodium. Mine was 116. The normal range is 136-145. I had no noticeable signs before I fell that anything was wrong.”
Hyponatremia is diagnosed when sodium levels fall below 135 mEq/L.

Priscilla in SC didn’t get a definitive diagnosis, but…

“I have used HCTZ for several years; did have infrequent muscle spasms in the lower legs, frequent urination, bladder incontinence. Quite recently I suffered a fainting spell, with accompanying dizziness and shakiness. I am presently under a cardiologist’s care after three days of hospitalization. Doctor suspects HCTZ but haven’t decided on clear diagnosis.”

The New BP Guidelines:

The American Heart Association and the American College of Cardiology have determined that all Americans should get their blood pressure to 130/80 or lower. That means that nearly half of all adults in the United states (103 million people) will be exhorted to lower their BP. And that means lots more prescriptions for diuretics.

Most people can tolerate diuretics like hydrochlorothiazides without problems. If such drugs work to control blood pressure without side effects, that is fabulous!

But we fear that many people will not be told about hydrochlorothiazide (HCTZ) side effects. They may not be monitored for sodium, magnesium, potassium or zinc on a regular basis.

Perhaps even more disturbing, many people won’t even realize they are taking a thiazide diuretic. That’s because it is often tacked on the end of the name of the BP medicine as HCT or HCTZ without much explanation or warning about adverse drug reactions.

Drugs Containing Hydrochlorothiazide:

  • Atacand HCT
  • benazepril HCTZ
  • Benicar HCT
  • bisoprolol HCTZ
  • candesartan HCTZ
  • captopril/HCT
  • Diovan HCT
  • enalapril HCT
  • eprosartan HCT
  • Exforge HCT
  • fosinopril HCT
  • hydrazine HCT
  • lisinopril HCTZ
  • Lopressor HCT
  • losartan HCTZ
  • metoprolol HCT
  • Micardis HCT
  • moexipril HCT
  • Monopril HCT
  • olmesartanHCT
  • propranolol HCT
  • quinapril HCT
  • spironolactone HCT
  • Tekturna HCT
  • telmisartan HCT
  • Teveten HCT
  • triamterene HCTZ
  • valsartan HCT

The People’s Pharmacy Perspective:

Diuretics like HCTZ are generally inexpensive. They lower blood pressure and can help control fluid build up (edema). Side effects are not as serious as with some other BP meds. But patients must be told about problems like dizziness, electrolyte imbalances and some of the potential complications like gout. Frequent blood tests are essential to make sure minerals like magnesium, sodium and potassium are not creeping into the danger zone. No one should stop this medication (or any other) without careful consultation with the prescribing physician. If hydrochlorothiazide (HCTZ) side effects become troublesome, however, doctors have a number of other options for treating elevated blood pressure.

Share your own story about diuretics in the comment section below. We want to hear success stories as well as tales of woe and intrigue.

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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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I am a 60 yr old male, been on hctz 12.5 mg for 14 years for hypertension, except for about a year when I only took Micardis (telmisartan). Over those years I have mostly taken the hctz 12.5/ telmisartan 40 mg combination. At one pt, 10yrs ago, had bad charley-horse cramps. My dr told me the combination with telmisartan will help to avoid cramps, which I have found to be true.
I want to try stopping the hctz. I have a suspicion it is not good for me in the long run. However it seems to induce a body relaxation I am noticing after not taking it for a few days, tapering off it. In some ways a muscle relaxing effect. I am resisting going back on it, yet in some ways crave it. My bp reading does not seem to correlate with the increased internal pressure I feel. It was 126/80 just before, which is fine.
These drugs can make you feel crummy in subtle ways often not easy to describe. But they may be preventing a stroke. It is interesting to note that Life Extension magazine recommended telmisartan over all other prescription rx’s for hypertension….good article to check out.

I have taken Lisinopril 20/12.5 for many years and also take fermented red beets as a supplement…Astaxanthin 4mg…Vit D3 50 K and K2 weekly..High allacin Garlic… Magnesium..and sublingual b12/b6/folate. I take no shots at all Flu etc. etc. I prefer natural supplements over meds and because I love the sun don’t want to take any BP meds at all. Thank you for this informative and eye opening article and starting next week will wean off the Lisinopril and take a natural supplement and hope I can keep my BP in check. I’m 75 and am more overweight than I should be so wish me well and I thank you for all your great advice and I have heard you on the local radio station out of Spr. MO. KWTO
Many thanks
Donna W.

My husband just started with HCTZ to lower his BP, and he says he doesn’t feel good…that’s all he’ll tell me. Previously he took lisinopril, and a few others that had to be stopped because the unsteadiness was too dangerous in his business. They gave him this 1 which is probably doing the same thing and more wrongs but all the doctors say is “it’s in your head”. He tells me…no clue what to do. They just did a cath that they didn’t have to do because they said they saw something on a n echo on the right, but it’s not bad enough to do anything…

I take enalapril 10/25mg HCTZ. I developed many skin problems–including a wart on the top of my breast. This RX also caused pain n my right knee, left elbow, foot and now gout at the base of my right toe. I am eating the correct diet to help eliminate the gout. It’s better but still lingers!

My husband was given hydrochlorothiazide when it was discovered he had high blood pressure…he also had another problem at the time with a diverticulitis attack that ruptured his intestine and needed immediate attention as well as 2 surgeries and a long recovery. He started back to work after being off for 2 months and almost immediately started in with gout attacks. He suffered from Gout a few years before this but changed his diet and lost 70 lbs and no longer had any problems, until the past few weeks. This past week he got to the point where every joint from his knuckles in both hands, wrists, knees, ankles, elbows. It was horrific! I got him in with his doctor and right away the doctor questioned who put him on the hydrochlorothiazide….we couldn’t believe it…this very doctor did! So come to find out hydrochlorothiazide can cause gout. So all this suffering and missed work was put on my husband when this doctor knew my husband had a history of gout!

I’ve been on HCTZ for about 20 years. I was advised that it would increase my sensitivity to the effects of the sun–sunburn and eye sensitivity to light. Although I haven’t had problems with sunburn (what with the typically cloudy weather we enjoy in western Oregon), I have noticed over the past several years increasing sensitivity to glare from headlights while driving at night. I suspect this little-known side effect may be a common cause for many motorist’s discomfort or inability to drive at night.

I took low dosage HCTZ for at least 20 yrs for high BP w/other BP meds. just this year i have had edema in ankles and legs and could not fit in my regular shoes for most of this year.

It must be the combination of drugs that I now take that has caused this change because I stopped taking HCTZ just a day or two and already the painful swollen edema is subsiding. Replaced it w/another low dose diuretic for now. I am 87 Yrs old.

The comment that edema got better after stopping HCTZ was surprising yet interesting. One of the reasons I was prescribed 12.5 HCTZ was that it would decrease the swelling in my legs and feet, which has gotten worse lately to the point of hurting. I also take Valsartan 80 for blood pressure. I shall wean off the HCTZ and see what happens.

I’d been off HCTZ for a while but started back (It’s prescribed for fluid retention.) This time around I had horrible cramps. Usually magnesium gel calmed them down but sometimes I had to soak in a bathtub of hot water before I could get to sleep.

How about tinnitus as a side affect?

I am a 94 year old female with not to high blood pressure. Primary has me on Fosinopril, Last visit he added HCTZ. In less than a week I had severe muscle pain — legs, arms, and hands. I could no longer hold the newspaper. NO MORE HCTZ!

This drug had a permanent effect on my memory. If I had continued I would he In a nursing home or cemetery. There are many thousands of people waiting to die because of it.

Some doctors and websites say that Lasix as well as HCT encourages gout episodes. Getting off Lasix did reduce gout and changing BP medication to one not containing an ingredient that causes edema all but eliminated swelling in my legs and ankles. Sometimes you have to get doctors to gang up on each other to get the best result.

What does ‘Electrolyte Imbalances’ really mean? Explain it in layman terms, please. Thank you.

I had been taking losartin HCTZ for about six weeks. The only reason I asked my husband to take me to the ER is because I could hardly draw a breath. I was hospitalized with severe low sodium and potassium. They said my heart and lungs were shutting down! Super scary!!!

Hi, thankyou for letting me share, Since being on Lasix I have lost my memory. I was told I had to go on it. Later on I got a second opinion and was told to get off lasix, but it was to late, my kidneys were already dependant on them. I am also on warfarin for blood clots. Please help me. I am feeling desperate.

I am now in Chronic renal failure. I begged the doctor not to put me on them…Lasix, but he said without them I would be in trouble with my heart. My other meds are Prozac 40mgs Klonopin-60mgs and an old tetra cyclic Mianserin- Every time I see him, He keeps upping the Dose. I am feeling almost paranoid…Can you get back to me…Thakyou….regards Kerry.

I tried to tell 2 different doctors that the antibiotic they had ordered was not working. Both said to continue taking it.
A urine culture backed up my instincts. Unfortunately, it was after taking the entire 10 days of a useless antibiotic.
So do listen to your body. It may be wiser than your doctor. At least do your own checking, even if it enrages the MD.

What is the alternative?? I never had hbp but my endocrinologist put me on losartan as an ace inhibitor to protect my kidneys… so far so good. But now I see there is a problem with the drug. What do you suggest?

Muscle Cramps doesn’t begin to describe my ordeal. I literally dropped to the floor in agony, was unable to straighten my legs and crawled to get a heat pad and Mustard. It was almost a daily episode. I finally quit the HCTZ and substituted Dandelion extract capsules and have been doing great with my B/P readings. I had also been taking amlodipine and have continued with that.

I have taken HCTZ/Triamterene for 25+ years. My body retains fluid if I miss a dose. How can I combat that to be able to stop taking it?

I was always told that Diazide was not a potassium lowering drug. Is it no longer?

I took this diuretic for ten years. It took a toll on my skin and eyes.

I took this diuretic for 10 years. No idea why. My eyes and aee cery dry now. My skin is dry. My Dr. changed the BP med to same thing just no diuretic. It has taken a toll on my skin. I have to moisturize twice a day now.

HCTZ was prescribed for me because of my HBP, which at times is over 200. After a few days I was barely able to walk or even lift much more than a newspaper. Stand for any length of time was impossible. I knew it had to be one of the newly prescribed BP meds. Research indicated that HCTZ was the most likely one. My doctor reluctantly prescribed something else. It only took a few days for the worst of the weakness to go away. Thank goodness for your articles and the Internet!

I’ve taken HCTZ for almost 30 years along with an ACE inhibitor. Lately, I’ve been worried about my electrolytes. blood sugar levels, and advancing age. I’m going to start seeing an integrative medicine practitioner soon, and I hope she can suggest an alternative to this drug and a couple others that may have negatively affected my health.

I was on various BP meds with HCTZ for years. When I discovered how sensitive I was to anticholinergics I asked my MD to stop it. It was much less needed as I had passed menopause and no longer retained fluid. My BP has been stable on Losartan alone. Losartan was about the 4th med because all of the others gave me a terrible cough. Horrible cough is another side affect MD’s refuse to believe.

I took HCTZ briefly and became so agitated I wanted to throw a chair through the window. I stopped taking it immediately, calling the doctor’s nurse to tell her so. My good physician said she’d not prescribe a diuretic for me again.

or LOSARTAN POTASSIUM, which i’m on: 50mg @ bedtime.
over a year now, but we’ll see.

I was in the hospital for low sodium (108) about 19 months ago. The hydrocholorithiazide was eliminated from my medications for several months. Now I am allowed 1/2 pill (12.5). Especially when I was off the drug and still now, my ankles/legs swell to the point of being very uncomfortable! What can I do to prevent this? My blood pressure is generally well controlled, but I hate the swollen legs!

Do the side effects of HCTZ also apply to the diuretic Chlorthalidone?

I stopped taking HCT because I was getting painful cramps beneath my rib cage. The doctor suggested that I needed to replace the electrolytes I was losing because of my blood pressure med lisinopril along with HCTZ. I took it one step further and stopped taking hydrochlorothiazide all together. My cramps are gone.

I have been taking Triamterene HCTZ daily for about ten years to control symptoms of Meniere’s disease. I have not suffered any adverse side effects of which I am aware. I wish I did not need it however it seems to work quite well at preventing debilitating spells of vertigo and dizziness so I am very thankful that it is available.

My mother was on HCTZ for mild elevated blood pressure about 10 years ago. After she was on it for about 2 weeks and had no warning about the severity of the side effects, she went on vacation and was out in the sun during the normal course of walking around–no sunbathing on the beach!

She got severely sunburned on her upper chest, above where her shirt’s neckline, was and it took about 6 months and many visits to a dermatologist to finally get her skin back to normal. Of course, when we told her cardiologist on our next visit, said she had never heard of such a side effect but said there was no need for her to really be on HCTZ because she did not have edema.

This confounded us as to why she prescribed something to begin, with if it was not necessary, and there were better alternatives. My mother has been on Norvasc since then with no side effects, other than mild dry mouth.

Sorry, but I think all medications are suspect. There are natural ways to lower BP and I will actively seek those out.

Could hydrochlorothiazide be causing the recent pins and needles feelings in my hands, some in my feet and legs? I have taken this drug every day for about 1 year or so. Thank you.

I have ended up in the ED more than once having to have a bolus of potassium due to HCTZ. I’ve had labile genetic hypertension for over 30 years so have always been prescribed something in addition to my angiotensin receptor blocker medication. Once the HCTZ was changed to Chlorthalidone I’ve had no issues with low potassium.

Thank you so much for writing in such detail about this critical information. It is so important that we learn about this and heed the warning’s and precautions.

I was prescribed Hydrochlorothiazide for hypertension. It seemed to work for a while. Then the dosage had to be increased for better control. Then i developed sensitivity to sun !ight. Terrible itching and very bad skin rashes. I did some research and ruled out other meds did not cause this and only HCT was the cause. Discontinuing it stopped the skin reaction.

My doctor never connected HCT with this condition.

My mother was prescribed HCTZ for years. Her potassium and sodium levels had not been tested in three years, although she saw doctor for yearly checkups. At around 82 years old, she ended up in hospital for three days due incredibly low sodium levels.

At the time, the area was in a very hot heat wave with very high temperatures and humidity. No air conditioning. She was sweating and drinking more water to stay hydrated. All of this worked together to cause the incredibly low sodium and potassium levels.

Her hands were beginning to shake. We were lucky she did have a seizure, or die. Her blood pressure medications were changed while she was in the hospital, taking her off HCTZ.

I think would only be fair to list the incidence percentage of the side effects listed herein. HCTZ has proven efficacy as first line treatment for hypertension (e.h. ALL HAT trial). The fact of the matter is, all drugs have “potential” side effects, including natural products. Does the benefit outweigh the risk? That’s the question the clinician must answer.

Hello Robert. May we assume you are a physician?

There is no question that HCTZ does help control high blood pressure. If you check the ALLHAT trial I think you will find that they used chlorthalidone, not HCTZ. Although many health professionals think of chlorthalidone as a thiazide-like diuretic it is actually quite unique. One cannot generalize.

We completely agree with you that “all drugs have ‘potential’ side effects, including natural products.” The point of our article is not to demonize thiazide diuretics but to point out that they can, on occasion, cause serious complications.

Patients need to be warned about symptoms to be alert for. They also need to be tested regularly for electrolyte imbalances. A potassium, sodium or magnesium deficiency can sneak up on a patient without a lot of warning signs. If you are indeed a physician you know that hypokalemia, hypomagnesemia, or hyponatremia are very very dangerous.

How can one evaluate the risk of taking an HCTZ if the numerical risk of developing one (or more) of these side effects is not known? My doctor thinks that these side effects are very rare – are there studies that show otherwise?

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