6 Hydrochlorothiazide Interactions You Should Know About

Hydrochlorothiazide (Microzide) is a popular diuretic (water pill) used to treat high blood pressure. It can also help with swelling from medical conditions like heart failure. It’s often combined with other medications for additive effects. This type of interaction can help you reach your blood pressure goal.

But not all hydrochlorothiazide interactions are beneficial. For example, alcohol, lithium, and pain relievers (like ibuprofen) can potentially cause problems. Some of these interactions can be managed, while others should be avoided altogether. 

So, which ones should you know about? Let’s discuss.

1. Other blood pressure medications

Hydrochlorothiazide (HCTZ) is a common first-choice medication for high blood pressure. And it’s often combined with different blood pressure medications for additive effects. In fact, HCTZ is found in several combination products for high blood pressure. 

Examples of blood pressure medications include lisinopril (Zestril), losartan (Cozaar), and amlodipine (Norvasc). Examples of combination products include Zestoretic (lisinopril/HCTZ) Hyzaar (losartan/HCTZ).

It’s not unusual to be taking more than one blood pressure medication. But sometimes this can lower your blood pressure too much, which is known as hypotension. If this happens, you may feel lightheaded or dizzy, which might cause you to faint or fall. 

These effects may be more apparent when you’re changing positions (like from sitting to standing). Be sure to change positions slowly to give your body time to adjust.

Your healthcare provider may have you monitor your blood pressure at home. Let them know if it’s getting too low. They may need to lower your medication dosage. 

2. Diabetes medications

HCTZ can affect your blood sugar levels and how your body responds to insulin. So, your diabetes medication may not work as well if you’re also taking HCTZ.

If you have diabetes, it’s important to regularly monitor your blood sugar. This shows if your medications are keeping your blood sugar levels under control. If they’re running higher than usual, this change could be due to HCTZ. Your healthcare provider may need to increase the dosage of your diabetes medication.

3. Lithium

Lithium (Lithobid) is used to treat mental health conditions, including bipolar disorder. Small changes in the amount of lithium in your blood can affect its safety and effectiveness. So, your levels are regularly monitored during treatment.

HCTZ causes your kidneys to remove more sodium. And low sodium levels can affect how much lithium is removed from your body. This can put you at risk of lithium toxicity from high lithium levels. 

Lithium toxicity can be life-threatening. Signs and symptoms include blurry vision, confusion, and muscle weakness or twitching.

In general, it’s recommended to avoid taking diuretics with lithium. But if you can’t avoid this combination, your lithium and sodium levels should be monitored closely. Let your healthcare provider know right away if you develop signs or symptoms of lithium toxicity.

4. Alcohol

If you’re taking HCTZ, you may be wondering if it’s safe for you to drink alcohol. Keep in mind that alcohol can affect your blood pressure. And it can interact with blood pressure medications, too.

In addition to hypotension, HCTZ can cause dehydration, dizziness, and electrolyte imbalances. All of these effects can also happen after drinking alcohol. So, it’s best to avoid or minimize alcohol while taking HCTZ. Your healthcare provider can tell you if there’s a safe amount for you to drink.

5. NSAIDs

If you’ve got a headache or fever, you might reach for a nonsteroidal anti-inflammatory drug (NSAID), like ibuprofen (Advil, Motrin), for relief. But you may want to use caution if you’re also taking a diuretic like HCTZ.

HCTZ may not work as well for you if you’re taking it with NSAIDs. That’s because NSAIDs can cause your kidneys to hold onto water and sodium — the opposite effect of HCTZ. What’s more, NSAIDs like ibuprofen can also increase blood pressure on their own.

This combination is even riskier if you’re also taking an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor blocker (ARB). Taking HCTZ, an NSAID, and an ACE inhibitor or ARB together can increase your risk of kidney damage.

For some people, occasional short-term NSAID use may not cause a significant problem. But your healthcare provider can recommend safer alternatives for your situation. 

6. Certain cholesterol medications

Cholestyramine (Prevalite) and colestipol (Colestid) are bile acid sequestrants. They can help lower cholesterol by binding to bile acids (substances made from cholesterol). However, they can bind to other medications, too.

When taken together, these medications can prevent your body from absorbing HCTZ. But this interaction can be managed by separating when you take each medication. Take HCTZ at least 1 hour before or 4 to 6 hours after taking cholestyramine. A similar rule applies to colestipol. Talk to your healthcare provider and pharmacist about how best to manage this interaction.

When should I contact my healthcare provider about a hydrochlorothiazide interaction?

Don’t hesitate to ask your healthcare provider about hydrochlorothiazide interactions. Most times, they’re likely already aware of them. But it never hurts to double check. As mentioned earlier, interacting medications are sometimes prescribed together and monitored closely.

Give your healthcare provider and pharmacist your current medication list ahead of time. This can help them identify potential interactions. Be sure to include any over-the-counter products and supplements. This is especially important when starting or stopping a medication.

That said, let them know if you start experiencing new or worsening side effects. This could be a sign that your dose is too high or low. Similarly, tell them if your medications aren’t working as well. They may need to make further adjustments to your regimen.

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Written by:

Timothy Aungst, PharmD

Timothy Aungst, PharmD, has worked in pharmacy practice for a decade. He has served as an associate professor of pharmacy practice, a clinical pharmacist in outpatient cardiology management, and now in home healthcare.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

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