Hydrochlorothiazide / Olmesartan Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 24, 2025.

Applies to hydrochlorothiazide / olmesartan: oral tablet.

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

Dizziness, lightheadedness, or fainting may also occur, especially when you get up suddenly from a lying or sitting position. Make sure you know how you react to the medicine before you drive, use machines, or do other things that could be dangerous if you are dizzy. If you feel dizzy, sit for a few moments before standing.

Check with your doctor right away if you become sick while taking this medicine, especially with severe or continuing nausea, vomiting, or diarrhea that does not stop. These conditions may cause you to lose too much water or salt and lead to low blood pressure. You can also lose water by sweating, so drink plenty of water during exercise or in hot weather.

Severe, chronic diarrhea with weight loss may develop months to years after taking this medicine. Tell your doctor right away if you have these symptoms.

Check with your doctor right away if blurred vision, difficulty with reading, eye pain, or any other vision change occurs with this medicine. This could be a sign of a serious eye problem. Your doctor may want an eye doctor to check your eyes.

This medicine may affect blood sugar levels. Diabetic patients may notice a change in the results of blood or urine sugar tests. Talk to your doctor if you have any questions.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, and herbal or vitamin supplements.

Other side effects

Some side effects of hydrochlorothiazide / olmesartan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects

Along with its needed effects, hydrochlorothiazide/olmesartan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking hydrochlorothiazide / olmesartan:

For healthcare professionals

Applies to hydrochlorothiazide / olmesartan: oral tablet.

General adverse events

The most common side effect was dizziness.^[Ref]

Nervous system

• Common (1% to 10%): Dizziness, headache
• Uncommon (0.1% to 1%): Syncope

Hydrochlorothiazide:

• Common (1% to 10%): Dizziness, headache
• Postmarketing reports: Lightheadedness, paresthesia

Olmesartan:

• Common (1% to 10%): Dizziness, headache^[Ref]

Respiratory

• Common (1% to 10%): Bronchitis, pharyngitis, sinusitis, upper respiratory tract infection, coughing, nasopharyngitis

Hydrochlorothiazide:

• Common (1% to 10%): Bronchitis, nasopharyngitis, pharyngitis
• Uncommon (0.1% to 1%): Sinusitis, upper respiratory tract infection, cough
• Frequency not reported: Pneumonitis, pulmonary edema

Olmesartan:

• Common (1% to 10%): Bronchitis, nasopharyngitis, sinusitis, upper respiratory tract infection, cough, pharyngitis, rhinitis^[Ref]

Other

• Common (1% to 10%): Vertigo, Influenza-like symptoms, chest pain, fatigue, peripheral edema
• Uncommon (0.1% to 1%): Weakness
• Postmarketing reports: Asthenia, lethargy, malaise

Hydrochlorothiazide:

• Common (1% to 10%): Vertigo, influenza-like symptoms
• Uncommon (0.1% to 1%): Chest pain, fatigue, peripheral edema
• Frequency not reported: Weakness, fever

Olmesartan:

• Common (1% to 10%): Vertigo, chest pain, fatigue, influenza-like symptoms, peripheral edema, pain
• Postmarketing reports: Asthenia, lethargy, malaise^[Ref]

Gastrointestinal

• Common (1% to 10%): Diarrhea, gastroenteritis, nausea, abdominal pain, dyspepsia
• Postmarketing reports: Sprue-like enteropathy, vomiting

Hydrochlorothiazide:

• Uncommon (0.1% to 1%): Diarrhea, dyspepsia, nausea, gastroenteritis
• Frequency not reported: Sialadenitis, cramping, gastric irritation
• Postmarketing reports: Constipation

Olmesartan:

• Common (1% to 10%): Diarrhea, dyspepsia, nausea, gastroenteritis, abdominal pain
• Postmarketing reports: Vomiting, sprue-like enteropathy^[Ref]

Musculoskeletal

• Common (1% to 10%): Back pain, creatine phosphokinase increased, arthralgia, arthritis, myalgia
• Uncommon (0.1% to 1%): Pain in limb, spinal disorder
• Postmarketing reports: Rhabdomyolysis

Hydrochlorothiazide:

• Common (1% to 10%): Arthralgia, back pain, pain in limb
• Uncommon (0.1% to 1%): Spinal disorder
• Frequency not reported: Muscle spasm

Olmesartan:

• Common (1% to 10%): Arthralgia, back pain, pain in limb, arthritis, skeletal pain, creatine phosphokinase increased
• Uncommon (0.1% to 1%): Spinal disorder, myalgia
• Postmarketing reports: Rhabdomyolysis^[Ref]

Metabolic

• Common (1% to 10%): Hyperlipemia, hyperglycemia, blood uric acid increased, hyperuricemia
• Uncommon (0.1% to 1%): Blood glucose increased, blood potassium decreased, blood potassium increased, hypertriglyceridemia
• Postmarketing reports: Hyperkalemia

Hydrochlorothiazide:

• Common (1% to 10%): Blood glucose increased, blood potassium decreased
• Uncommon (0.1% to 1%): Blood uric acid increased
• Frequency not reported: Hyperglycemia, glycosuria, hyperuricemia
• Postmarketing reports: Anorexia, loss of appetite

Olmesartan:

• Common (1% to 10%): Hypertriglyceridemia, hyperglycemia, hyperuricemia
• Uncommon (0.1% to 1%): Blood glucose increased, blood potassium decreased, blood uric acid increased
• Rare (less than 0.1%): Hyperkalemia
• Frequency not reported: Hypercholesterolemia^[Ref]

Hepatic

• Common (1% to 10%): GGT increased, AST increased, ALT increased

Hydrochlorothiazide:

• Uncommon (0.1% to 1%): ALT increased, AST increased, GGT increased
• Frequency not reported: Pancreatitis, intrahepatic cholestatic jaundice

Olmesartan:

• Common (1% to 10%): ALT increased, AST increased, GGT increased^[Ref]

Genitourinary

• Common (1% to 10%): Hematuria, urinary tract infection

Hydrochlorothiazide:

• Common (1% to 10%): Urinary tract infection

Olmesartan:

• Common (1% to 10%): Urinary tract infection, hematuria^[Ref]

Psychiatric

• Uncommon (0.1% to 1%): Anxiety, insomnia

Hydrochlorothiazide:

• Uncommon (0.1% to 1%): Anxiety, insomnia
• Frequency not reported: Restlessness
• Postmarketing reports: Sleep disturbances, depression

Olmesartan:

• Common (1% to 10%): Insomnia
• Uncommon (0.1% to 1%): Anxiety^[Ref]

Dermatologic

• Common (1% to 10%): Rash, facial edema
• Uncommon (0.1% to 1%): Eczema
• Postmarketing reports: Alopecia, pruritus, urticaria

Hydrochlorothiazide:

• Frequency not reported: Purpura, photosensitivity, urticaria, Stevens-Johnson syndrome, toxic epidermal necrolysis
• Postmarketing reports: Rash, cutaneous lupus erythematosus-like reactions, reactivation of cutaneous lupus, erythematosus

Olmesartan:

• Uncommon (0.1% to 1%): Rash
• Postmarketing reports: Alopecia, pruritus, urticaria^[Ref]

Immunologic

• Common (1% to 10%): Influenza
• Uncommon (0.1% to 1%): Viral infection
• Frequency not reported: Angioedema
• Postmarketing reports: Anaphylactic reactions

Hydrochlorothiazide:

• Uncommon (0.1% to 1%): Influenza, viral infection
• Frequency not reported: Anaphylactic reactions

Olmesartan:

• Common (1% to 10%): Influenza
• Uncommon (0.1% to 1%): Viral infection
• Postmarketing reports: Angioedema, anaphylactic reactions^[Ref]

Renal

• Uncommon (0.1% to 1%): Blood creatinine increased
• Postmarketing reports: Acute renal failure

Hydrochlorothiazide:

• Uncommon (0.1% to 1%): Blood creatinine increased
• Frequency not reported: Renal failure, renal dysfunction, interstitial nephritis

Olmesartan:

• Uncommon (0.1% to 1%): Blood creatinine increased
• Postmarketing reports: Acute renal failure^[Ref]

Cardiovascular

• Uncommon (0.1% to 1%): Palpitations, hypotension, orthostatic hypotension

Hydrochlorothiazide:

• Frequency not reported: Vasculitis, cutaneous vasculitis
• Postmarketing reports: Cardiac arrhythmias, postural hypotension

Olmesartan:

• Uncommon (0.1% to 1%): Tachycardia, angina pectoris
• Rare (less than 0.1%): Hypotension^[Ref]

Hematologic

Hydrochlorothiazide:

• Frequency not reported: Aplastic anemia, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia
• Postmarketing reports: Bone marrow depression^[Ref]

Ocular

Ocular side effects have included idiosyncratic reactions to the hydrochlorothiazide component resulting in acute transient myopia and acute angle-closure glaucoma.^[Ref]

See also:

Further information

Hydrochlorothiazide/olmesartan side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer