Specifically, the Food and Drug Administration (FDA) has approved metolazone oral tablet for:
- edema from congestive heart failure
- edema from kidney disease
- high blood pressure, alone or in combination with other blood pressure medications
This article describes possible side effects of metolazone oral tablet. You can explore this overview article to learn more about metolazone, including the drug’s uses, ways to save on cost, and more.
Metolazone oral tablet is a generic medication. It isn’t available in a brand-name version.
Need a diagnosis or prescription quickly? For certain health conditions, Optum Perks offers personalized on-demand care with no appointment required. For $25, answer a few questions online and receive a diagnosis and treatment plan from a board certified healthcare professional in 15 minutes or less. Get started here.
More common side effects of metolazone
Metolazone oral tablet may cause mild or serious side effects. Below are some of the more common side effects of this medication.
Commonly reported side effects of metolazone oral tablet include:
Mild side effects of metolazone
Metolazone may cause certain mild side effects. Usually, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.
Mild side effects of metolazone oral tablet that occurred in studies include:
- abdominal pain
- bloating
- constipation
- diarrhea
- dizziness
- drowsiness (sleepiness)
- dry mouth
- fatigue (low energy)
- headache
- increased sensitivity to sunlight, which can lead to sunburn and skin cancer
- loss of appetite
- muscle cramps
- nausea or vomiting
- restlessness
- temporary blurry vision
- weakness
- mild allergic reaction*†
Metolazone oral tablet may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.
* To learn more about this side effect, see the “Side effects of metolazone in detail” section below.
† An allergic reaction is possible with metolazone oral tablet. But it’s unclear whether it occurred in the drug’s studies.
Serious side effects of metolazone
Metolazone may cause certain serious side effects. If you have any serious side effects from metolazone oral tablet, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.
After the FDA approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with metolazone.
Serious side effects of metolazone oral tablet that occurred in studies include:
- dehydration*
- high blood sugar
- high calcium levels
- high uric acid levels, which can increase the risk of gout attacks
- kidney problems
- liver problems
- low blood cell counts, including red blood cells, white blood cells, and platelets
- low magnesium levels
- low potassium or low sodium levels*
- nerve problems
- new or worsening systemic lupus erythematosus (SLE)
- sudden low blood pressure*
- severe allergic reaction*†
* To learn more about this side effect, see the “Side effects of metolazone in detail” section below.
† An allergic reaction is possible with metolazone oral tablet. But it’s unclear whether it occurred in the drug’s studies.
Download the free Optum Perks Discount Card to save up to 80% on some prescription medications.
Free prescription coupons
Seriously … free. Explore prices that beat the competition 70% of the time.
Get free card
Common questions about side effects of metolazone
Here are answers to some common questions about side effects of metolazone oral tablet. If you have other questions, talk with your doctor or pharmacist.
Is metolazone safe for older adults?
Yes, metolazone is generally safe for older adults. But the prescribing information for metolazone recommends using a lower starting dose for adults ages 65 years and older. This is because organ function, especially kidney function, can decrease with age.
Your kidneys help get rid of metolazone from your body. When they don’t work as well as they should, metolazone levels can build up in your body. This can cause side effects to be more common and more severe.
If you have concerns about using metolazone given your age, talk with your doctor. They may recommend checking your kidney function from time to time while you take metolazone.
Does metolazone cause long-term side effects?
Long-term side effects aren’t expected with metolazone oral tablet. In studies, specific side effects weren’t seen in people who had taken the drug for a long time. Long lasting side effects after treatment ended also weren’t reported.
Talk with your doctor if you have more questions about possible long-term side effects of metolazone.
Side effects of metolazone in detail
Below you’ll find details on some of the side effects of metolazone oral tablet.
Low potassium or low sodium levels
Low potassium levels have been reported in people taking metolazone oral tablet. Low sodium levels can also occur with low potassium levels. This side effect may be serious.
In rare cases, low potassium levels and low sodium levels were very severe and happened very quickly after starting the drug. If this happens, it can lead to life threatening heart problems.
Symptoms may include:
- atypical heart rhythms, which can feel like pounding or fluttering in the chest
- drowsiness (sleepiness)
- fatigue (low energy)
- increased thirst
- muscle cramps or pain
- nausea or vomiting
- dry mouth
- weakness
Low potassium levels can happen at any time during treatment with metolazone. But it’s more common with higher doses. Certain other factors can increase the risk of low potassium levels with metolazone oral tablet. These include:
- taking certain other medications, including corticosteroids
- diarrhea
- liver problems
- certain heart arrhythmias (irregular heart rate or rhythm)
- vomiting
Ways to manage
Your doctor will check your potassium levels from time to time during metolazone treatment. They may suggest taking a potassium supplement if your levels of potassium start to get low.
If you experience symptoms of low potassium, get medical care right away.
Dehydration
Dehydration has been reported in people taking metolazone oral tablet. This side effect may be serious.
With dehydration, you don’t have enough fluids in your body. It can happen if you don’t drink enough water. It can also happen if you lose a lot of fluids through sweat, diarrhea, or vomiting.
Symptoms may include:
- dark yellow urine
- dry mouth
- fast breathing
- fast heart rate
- not urinating very much
- skin that stays pinched after you let go of it
- increased thirst
Being dehydrated can cause problems with low potassium and low sodium.
Ways to manage
You can help prevent dehydration by drinking plenty of fluids, especially water, throughout the day. Drink extra fluids if you:
- are in hot or humid weather
- are sweating
- are vomiting
- have diarrhea
If you experience symptoms of dehydration, get medical care right away.
Sudden low blood pressure
Sudden low blood pressure has been reported in people taking metolazone oral tablet. This side effect may be serious.
With metolazone, you can have sudden low blood pressure when you stand up or sit up. This is called orthostatic hypotension. It can lead to fainting, which can cause serious falls and injuries.
Other symptoms may include:
- blurry vision
- fast, slow, or atypical heart rate
- increased angina (chest pain)
- nausea or vomiting
- paleness (loss of color)
- sweating
- vertigo (sensation of motion or spinning)
- weakness
Certain factors can increase the risk of sudden low blood pressure with metolazone. These include:
- dehydration
- drinking alcohol
- taking narcotics (opioids) or sedatives
- taking other blood pressure medications
Ways to manage
If you have symptoms of low blood pressure or feel like you’re going to faint, sit or lie down until you feel better. Then, get up slowly to avoid problems again.
Tell your doctor if you experience dizziness or fainting. Get medical help right away if you fall or injure yourself.
Allergic reaction
For some people, metolazone oral tablet can cause an allergic reaction.
Symptoms can be mild or serious, and they may include:
- itchiness
- skin rash
- severe skin rashes that may blister and peel, including Stevens-Johnson syndrome
- swelling under the skin, typically affecting eyelids, lips, hands, or feet
- swelling of the mouth, tongue, or throat, which can make it hard to breathe
- flushing (temporary warmth, redness, or deepening of skin color)
Ways to manage
For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.
For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to metolazone oral tablet, your doctor may recommend taking a different medication instead.
Warnings for metolazone
Below are some factors you may want to discuss with your doctor before taking metolazone oral tablet.
Warnings
It may not be safe for you to take metolazone oral tablet if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether metolazone oral tablet is a safe treatment option for you.
Before taking metolazone oral tablet, tell your doctor about your health and medications you take. Things to consider include:
- diabetes
- gout
- heart problems
- kidney disease
- liver disease
- parathyroid problems
- SLE
- past allergic reaction to metolazone
Metolazone and pregnancy
It’s not known whether metolazone oral tablet should be taken during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.
Metolazone and breastfeeding
Metolazone oral tablet should not be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication. Your doctor may recommend other ways to feed your child during treatment with metolazone.
Metolazone and alcohol
Metolazone oral tablet is known to interact with alcohol.
Drinking alcohol while taking metolazone can increase the risk of sudden low blood pressure. This can lead to fainting and serious injuries.
If you drink alcohol, talk with your doctor about whether it’s safe to consume it during your treatment with metolazone oral tablet.
What to ask your doctor
This article describes common and serious side effects of metolazone oral tablet. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.
Here’s a list of some possible questions you may want to ask your doctor:
- Do I have a higher risk of metolazone side effects than other people?
- Do any of the other drugs I take increase my risk of side effects from metolazone?
- How can I manage the most common side effects of metolazone?
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.