Q. My husband was prescribed HCTZ (hydrochlorothiazide) for high blood pressure. At the same time, his blood sugar was tested (HbA1C) and we were told that he was “not diabetic”.
Four months later, he ended up in the emergency room with low potassium and his blood sugar was again tested and he “was not diabetic.” Two months after that (6 months on HCTZ), he was in the ER again, this time with diabetic ketoacidosis (DKA). He was in intensive care for 5 days with insulin therapy, during which time I did more intensive research myself. The Doctor refused to acknowledge that the problem was caused by the HCTZ, and insisted that he was an “undiagnosed diabetic,” even though the prior hospital testing proved otherwise.
Doctors wanted him back on the HCTZ when discharged, and we refused. Came home from hospital and the next day we were back at the Doctors office due to a bad reaction to the insulin.
After getting off the hydrochlorothiazide completely he was able to stop all diabetes medication. The doctor still insists that he is diabetic, even though his most recent HbA1C rest results came back: “not diabetic.”
A. It is quite surprising to us that your husband’s physicians had such a hard time acknowledging that the diuretic HCTZ (hydrochlorothiazide) could have raised his blood sugar levels high enough to trigger a diagnosis or diabetes. This is a well-known adverse reaction to a great many diuretics such as:
• Bendroflumethiazide (Naturetin)
• Benzthiazide (Exna)
• Bumetanide (Bumex)
• Chlorothiazide (Diuril, Diachlor, Diurigen)
• Chlorthalidone (Hygroton)
• Ethacrynic acid (Edecrin)
• Furosemide (Lasix)
• Hydrochlorothiazide (Esidrix, HydroDIURIL, Oretic)
• Hydroflumethiazide (Diucardin)
• Methyclothiazide (Aquatensen, Enduron)
• Polythiazide (Renese)
• Trichlormethiazide (Diurese, Metahydrin, Naqua)

HCTZ (also abbreviated HCT) is often found in other popular blood pressure medications such as:

Atacand HCT
Benicar HCT
Diovan HCT
Exforge HCT
Lopressor HCT
Lotensin HCT
Micardis HCT
Tekturna HCT
Teveten HCT
All the medications listed above have the potential to raise blood sugar and in some susceptible individuals may even trigger frank diabetes.
It is totally surprising that the doctors described your husband’s situation as “undiagnosed diabetes.” The FDA requires the following language in the official prescribing information:
“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.”
In truth there are a lot of unresolved questions about the blood sugar elevations brought on by drugs. The FDA seems to be blaming the patient by suggesting that “latent” diabetes or “undiagnosed diabetes” exists before the drug is given. The assumption seems to be that diabetes, though undiagnosed, is a pre-existing condition. Other researchers have suggested that low potassium levels, brought on by these drugs might also be a contributing factor. There is also evidence that these diuretics decrease the amount of insulin released by the pancreas.
Regardless of the mechanism, there is little doubt that such drugs can precipitate diabetes. What is not clear is if a person like your husband never received a diuretic like HCTZ whether he would develop diabetes anyway.
Symptoms of diabetic ketoacidosis include:

• Great thirst
• Frequent urination
• Weakness, exhaustion, fatigue
• Digestive distress (stomach pain, nausea, vomiting)
• Difficulty catching your breath, fruity smelling breath
• Confusion

This is a potentially life-threatening situation and required immediate medical attention!
There are dozens of other types of medications that can trigger elevated blood sugar or even diabetes. Just a few examples include:

• Leuprolide (Lupron)
• Prednisone
• Statins (atorvastatin, lovastatin, rosuvastatin, simvastatin, etc.)
• Tacrolimus (Prograf)
• Triamcinalone

If you would like to learn more about drugs that can raise blood sugar levels we suggest our brand new Guide to Managing Diabetes. In addition to a list of drugs, you will find insights into the best diet for diabetes, a variety of non-drug approaches including herbs and spices for better blood sugar control (including cinnamon).
Even if you do not have diabetes, we think this new guide will provide valuable information about healthy eating habits for everyone. Diabetes and pre-diabetes have become epidemic in America. We hope our new guide will be helpful in helping people make informed choices to prevent or better deal with this condition. Here is a link to the guide.

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  1. A.Boondy
    New York, NY

    I was off of Hydrochlorothiazide, simvastatin, and lisinopril for a week since I needed a refill. I am diabetic and am having a hard time controlling it with humulin nandinsulin and a very low carb diet. while I was off for a week on those meds, I noticed that my glucose numbers were normal during that week.

    That was proof enough for me to rethink what the doctors are putting me on…its like they want to keep me on the meds, so I can fill their pockets and keep coming back at least 8 times a year for visits.

  2. Kim
    Windham, ME

    I was diagnosed with diabetes over 6 years ago and even though I think that because of poor health, poor eating habits, and sedentary lifestyle I probably would have eventually became a diabetic, I believe that it was hydrochlorothiazide that pushed me over the edge and made it happen much sooner than would have otherwise. Diabetes does not run in my family. I am the only one with it. Since I got off the hydrochlorothiazide and the simvastatin, my blood sugars have been getting lower, I got off Invokana (a diabetes med) and will soon have to talk to my doctor about reducing my insulin. I am also taking vitamins, supplements, Natural Calm Magnesium, Diabetes Free Formula (herbal extracts from Dr. David Pearson’s diabetesfree.com), multi-enzyme formula, also walking 1-1 3/4 miles a day, and eating as much organic as I can afford. I am making great progress and I am determined to beat this diabetes but whatever you do, Don’t let your doctor put you on any of the medications listed in this article. You do not want to become a diabetic. Not only does it change your life but it could kill you. My girlfriends aunt was diagnosed the same year as me and six years later she is dead. I took it very seriously but she didn’t change anything but took more meds. Don’t let it happen to you.

  3. Nina

    Triamterene almost killed me. I was given it as I had swollen ankles. I ended up having to pee every 20 minutes, had a head ache that would not go away, and lost 10 lbs. in 2 days. Those who don’t believe me, I have proof of my medical record showing my weight when I first went to the doctor and when I went back. I should have gone to the ER, I was severely dehydrated. If you have fluid retention, go for something otc like diurex which is something I can actually take without getting sick. If you are type 2 like me your doctor should NOT be prescribing this drug. Period.

  4. SalW

    My 75-year-old husband experienced two hypertension crises resulting in visits to the ER following his recent back surgery. Our geriatrist and his cardiologist placed him on a number of blood pressure meds to control the situation. He was placed on amlodipine, clonidine patch, metoprolo succinate, and benicar HCT. I am pre-diabetic and daily monitor my blood glucose. After reading about the possible side effects of benicar HCT, I started testing his fasting blood glucose and saw it rising to 111 and 118.
    He made an appointment yesterday with our geriatrist because he was complaining of itching (a possible allergic reaction to the HTC), pain in his upper and lower arms, and elevated blood glucose. I sent the benicar pharmacy insert with him that clearly stated and underlined that the benicar HCT could raise blood glucose. The doctor still stated that none of his meds could raise blood glucose! He will now take regular benicar, metoprolol tartrate, the clonidine patch and amlodipine.
    I have become convinced that many doctors simply do not want to know of many drug side effects because the information might result in a possible lack of confidence they have in certain medications. It is hard to keep up with all the side effects.
    The FDA does add new side effects to medication inserts but only if enough people experience them. I also believe that many drugs are approved before they are fully tested and for longer periods of time. With the pharmaceutical companies doing the testing, the results often have to be somewhat skewed!

  5. mb

    I plan on having a conversation with my doctor regarding HCTZ…which is part of my diovan (now generic)…I know she will give me a hard time, but I would like to give it a try….she does not go along with your opinions! But I do, if they make sense….so tired of doctors pushing drugs for every little thing…I almost don’t like to tell her something is bothering me…another pill!!

  6. HJL

    Congratulations you are probably the only Dr. in the U.S. who can make that claim. Metabolic syndrome can develop into diabetes and often those suffering
    had high BP treated by diuretics and they subsequently go diabetes. This does not say that the diuretic caused the diabetes, but to say no patient in 30 years who ever took HCTZ developed diabetes is just incredible. If you want to say in your opinion none of your patients developed diabetes from HCTZ so be it, but to say none ever developed diabetes is going too far.

  7. SalJ

    In response to Dr. EBM, I in no way believe that the Graedons are “promoting dissent and insidiously advising patients to question the competence of their physicians.” They simply are reporting a patient’s experience and that the diuretic HCTZ (hydrochlorothiazide) could have raised his blood sugar levels high enough to trigger a diagnosis of diabetes. They are not telling people to abandon their medications (and never do) but simply to be aware of possible side effects causing diabetes, which are the exact same warnings enclosed with the inserts I receive in my losartan/HTZ and amplodipine prescriptions from the pharmacy.
    Pharmaceutical companies list the side effects they absolutely have to…no more. Most physicians have little information aside from what they’ve been told by their drug reps. I like to be in partnership with my internist specializing in geriatrics, but he does not keep up with recent studies so easily available to everyone, including doctors. When my blood glucose suddenly became elevated, I showed him recent studies (The Lancet, Archives of Internal Medicine and JAMA), revealing that women especially over age 50 taking statins could experience a significant risk of developing diabetes, he wouldn’t even read it saying, “It depends who you listen to.” At the end of our meeting, he said, “I do have a doctorate.”
    I didn’t have high cholesterol but I do have uncontrollable risks for diabetes, so I took myself off my pravastatin, because I realize this drug I have taken for a long time could become a problem as I have gotten older (I am 74). He also prescribed levaquin (with a bold black box warning) to my husband who could hardly walk after only three of five tablets for bronchitis; our elderly neighbor ruptured his Achilles tendon while on long-term Cipro.
    With a now elevated blood glucose, I am looking into all areas for improving this situation to include diet, exercise and medications since 96 percent of the nearly 26 million Americans with diabetes have type 2 diabetes and I don’t want it. In the meantime, I welcome further newsletters from the Graedons with their up-to-date messages and alerts.

  8. Michelle

    I have had many pts on HCTZ and it can cause hyperglycemia, but I have yet to see a pt develop diabetes from HCTZ after 30 yrs of practice.
    PEOPLE’S PHARMACY RESPONSE: We appreciate that it is not common and also that HCTZ and other thiazide diuretics are incredibly useful drugs. Clearly, Dr. EBM agrees with you, and there is a lot to be said for your collective experience.
    We do think patients should be aware of possible complications, however.

  9. HJL

    Sorry EBM, I think your attack on the Graedons was over the top. I don’t think you read every word of what the Graedons said.
    You may be the best emergency doc in the world, but you deal with patients on a short term basis. Managing long term care has its own set of requirements.There are many docs out there who are not good, who don’t keep up and don’t listen. For a doc to deny the possibility that a diuretic could cause onset diabetes is malpractice.
    Your mother acted reasonably asking you for help about her lisinipril. What’s the big deal? There is nothing non-factual in what the Graedons said. Besides the diabetes issue, they raise the fact that perhaps potassium supplementation should be explored.
    I read almost all of the article you cited and do not have the background to understand everything in it. But I found nothing in it that contradicts anything the Graedons said. In fact it supports it. This is a direct quote from the article you cited: (Note: NOD is onset diabetes)
    “In conclusion, we should refrain from underestimating the adverse prognostic impact of NOD induced by diuretics and β-blockers, alone or combined, solely because of the failure by most randomized trials to disclose a significant association between NOD and outcome. NOD, whether or not induced by drugs, remains an important adverse prognostic marker that should be prevented. We suggested that in subjects at increased risk of NOD (impaired fasting glucose, obesity, metabolic syndrome), diuretics and β-blockers should 1) be used cautiously, with the lowest effective dose and plasma glucose periodically checked, and 2) be avoided in subjects with BP normalized by different classes of antihypertensive drugs.”
    I am sorry your mother “bothered” you with her reasonable question. But please read your own sources more carefully before you attack others who are completely factual. If I am wrong, cite one factual error in what the Graedons said. And please read carefully so you don’t quote from what others above said.

  10. DanG

    Is it possible that the treatment mentioned in the 18Jan13 program – the treatment with the yuck factor, i.e. bacteriotherapy, to be polite… Could that treatment be useful in management of diabetes? Diabetes is definitely a digestive disorder, i.e. no insulin to process digested food to essential use by body. Perhaps a reset of systems using transplant as happens in bacteriotherapy might cause vagus nerve feedback loops to also reset and begin proper function?
    PEOPLE’S PHARMACY RESPONSE: We don’t know of any data supporting the use of fecal transplant for diabetes. There may be other digestive conditions that would respond, however.

  11. EBM

    As a Board Certified Internist and Emergency Room physician for 21 years, I must reply to this. My mother sent me the link wondering if my taking of Lisinopril would also “trigger diabetes”.
    Please read this article in its ENTIRETY to better understand the pros and cons of thiazide diuretics. Perhaps it will persuade the reader to not leap to the conclusions so irresponsibly presented in this web discussion.
    Joe and Terry, you are promoting dissent and insidiously advising patients to question the competence of their physicians with poor research examples and a lack of unbiased attention to the real data available. Its embarrassing even reading what is presented here.
    And just to settle the issue….
    If you choose to not take a medication because of a side-effect that “might” happen, then you might as well take nothing. There’s no such thing as a harmless medication, be it herbal, “natural”, or pharmaceutical. Medicines can harm and they can help. We, as physicians, deal with the “probable”…this is a fact of medicine. There ARE no absolutes. HCTZ will PROBABLY not cause you to get diabetes. Can’t say absolutely, but PROBABLY not. If you get diabetes on it, its far more likely you developed the diabetes for other reasons (as the article linked mentioned). Any physician worth his salt would certainly look to consider an alternative if necessary, but if the benefit of the HCTZ outweighs the risk, then the best choice MIGHT be to continue it. Perhaps the diabetes can be managed with the same diet that SHOULD have been present before the HTN started….i.e. low sodium and low carb.
    Again, thoroughly irresponsible article leading your viewers to thoroughly erroneous conclusions. Then again, its all about the controversy generated, isn’t it?
    PEOPLE’S PHARMACY RESPONSE: EBM, I’m curious why you didn’t just reassure your mother that lisinopril is not a diuretic and doesn’t raise blood sugar?

  12. Michelle

    I am a physician and I am not in “ka-hoots” with any pharmaceutical company or the government. I actively work to keep my patients off prescription medications and decrease dosages whenever possible. I do not view patients as the key to making lots of money. My goal is to make my patients as healthy as possible through lifestyle changes, etc.
    Many patients expect physicians to treat every little thing with a pill rather than making changes on their own to improve their health and well-being. In addition, physicians are not God and do not have complete knowledge of all the many side effects and complications of medications or diseases. We are limited by time and evidence available.
    Studies available to us are continually changing, which makes it difficult to predict what may or may not occur in the course of treatment. We are also not paid that well as primary care physicians. There is a limit to what can be reasonably expected from physicians. All people need to do their own research and present it to the physician. Any decent physician will be happy to look at the information available. If not satisfied, get a second opinion.

  13. Betty T.

    My doctor recently put me on Amlodipine for blood pressure. I was already taking pravastatin for high cholesterol. I am a 65 year old female. I don’t want to end up with diabetes. Should I talk with my Doctor about these medications?

  14. CAK

    So many folks, it seems, are having more problems from drugs they are taking than the problem for which it was prescribed. Aren’t we constantly hearing about the problems caused by statins? That’s why the following book raised a red flag for me: THE GREAT CHOLESTEROL MYTH; Why Lowering Your Own Cholesterol Won’t Prevent Heart Disease and the Statin-free Plan That Will, by nutritionist Jonny Bowden and Dr Stephen Sinatra. (I recall hearing Dr Sinatra as a guest on People’s Pharmacy radio show some time ago.) I would appreciate some feedback on this.
    PEOPLE’S PHARMACY RESPONSE: Stay tuned. We have interviewed them and will have them on the air in the next few months.

  15. Barbara

    This week my cardiologist told me 15% of patients who take diuretics get diabetes.
    I did not see Bystolic on you list of diuretics that cause diabetes so I am asking, is Bystolic a diuretic that causes diabetes, and do all diuretics cause diabetes?

  16. jas

    My 80 yr. old mother is in good health but her doctor saw her blood pressure getting higher (140-150) and he put her on the lowest dose of hydrochlorothiazide. She rarely, if ever, takes it but we, her kids, have been pestering her to take it. Now I’m wondering if she did the right thing. Her blood sugar is pre-diabetic. Thanks for the heads up…
    I seem to get more info from the People’s Pharmacy than any of the doctors I go to. In fairness, I don’t expect doctors to be pharmacists, but considering that they push these drugs with BIG side effects…. I’m wondering if doctors should have a pharmacist solely dedicated to their practice to “consult” with…. before they push various drugs, especially the newer, unproven drugs that are tested on someone on the other side of the world who is desperate for money and needs to be a guinea pig just for the money. Hope Big Pharm is reading all our posts here on People’s Pharmacy… just to let them know we’re not going to blindly trust their products no matter what the television ads say or even what the doctor’s say….

  17. SalJ

    I have just discovered a very informative website that lists drugs that can affect blood glucose levels which can be used as a dialog and reference basis with a patient’s doctor. It is http://www.diabetesincontrol.com.

  18. HJL

    Just for the record, ketoacidosis mentioned above by the Graedons is dangerous. It should not be confused with ketosis which is considered harmless. Ketosis is the result of an Atkins diet with low carbs and more protein and fat. One is in ketosis when urine turns paper test strips a different color indicating ketones are in the urine. This is exactly what should happen on this type of diet and is a good thing. Dietitians often tell people ketosis is dangerous which it isn’t. Many think the dietitians are confusing ketosis and ketoacidosis which is an entirely different thing.
    Graedons, correct me if I misstated anything.

  19. L.A.

    Penny, that’s s shame that happened to you. These doctor’s are in ka-hoots with the pharmaceutical companies who are holding hands with the government. Sick people are big business and mean about of money for them. Woe to the sick and anyone who thinks they may be sick because the doctor’s are going to find any excuse to put you on medication. SMH

  20. SalJ

    I am a 74-year-old female and I receive more valuable information from your website than I do from my internist (about to retire) who even specializes in geriatric medicine. I, too, was falsely suspected of being a Type 2 diabetic but was saved only by an HbA1C test.
    In the meantime, I did receive a glucose monitor and then further verified what I suspected was causing my elevated glucose. I got off the daily dose of 5 mg of Amplodipine I was taking with my Losartan/HCTZ 100-25. I now realize that the Losartan also may be a partner to that problem. Both drugs can cause problems with older people who have or are prone to diabetes. I also am allergic to sulfa which can be a problem with Losartan which hasn’t seemed to be a noticeable problem right now.
    Perhaps the elderly have more problems with these and many other drugs. I have been told that pharmaceutical companies do their testing mostly on men only, so why wouldn’t we women have a harder time with the dosage of many drugs?
    Thanks to you and Dr. Mercola and the studies you both cite, I got off my statin Pravastatin because it also can cause diabetes in older women.
    No wonder so many people are being diagnosed with diabetes these days. Perhaps many medicines are actually contributing to this problem.
    I have some risk factors beyond my control for diabetes and am presently somewhat insulin impaired, so I want to do whatever I can to be in complete control of my medical destiny. My doctor won’t be too happy when I now ask him to change my Losartan to something else. He hasn’t been very receptive to my discontinuance of the Amplodipine and Pravastatin because he doesn’t keep up with newer studies.

  21. Penny H.

    Years ago I had a doctor who had a couple of “favorite” diseases. They were gout and cortizone deficiency. He put me on allopurinol and prednisone 7.5mg and I took both medications for many years. When I changed doctors my new doctor said the prednisone was bad for me but I probably couldn’t get off it.
    Meanwhile I started having back problems and another doctor insisted that I could be fixed by having three steroid shots in my spine. The shots didn’t work. I weaned myself off of prednisone. Later that same year I was diagnosed with diabetes and high blood pressure. It’s been 15 years. My diabetes is well controlled as is my blood pressure. My internist retired and my new doctor says I don’t have gout and took me off the allopurinol.
    I have bad reactions to many drugs, even some that are considered harmless. Meanwhile I’m stuck with a number of “pre-existing” conditions that might never have happened without the “help” that the doctors gave me.

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