Diovan HCT Side Effects

Generic Name: hydrochlorothiazide / valsartan

Note: This page contains information about the side effects of hydrochlorothiazide / valsartan. Some of the dosage forms included on this document may not apply to the brand name Diovan HCT.

Not all side effects for Diovan HCT may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to hydrochlorothiazide / valsartan: oral tablet

In addition to its needed effects, some unwanted effects may be caused by hydrochlorothiazide / valsartan. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking hydrochlorothiazide / valsartan:

Less common
  • Cold or flu-like symptoms
  • difficulty with swallowing
  • sore throat
  • tender or swollen lymph nodes in the neck
  • unusual tiredness or weakness
  • Bloating or stomach pain
  • blurred vision
  • chills
  • eye pain
  • fainting
  • fever
  • flushing
  • itching, pain, redness, or swelling of the eye or eyelid
  • joint stiffness or swelling, especially if sudden
  • nausea
  • skin rash or hives
  • trouble with breathing or wheezing
  • vomiting
  • watering of the eyes
  • yellow eyes or skin
Incidence not known
  • Confusion
  • convulsions (seizures)
  • dark urine
  • decreased urine output
  • dizziness
  • drowsiness
  • dry mouth
  • fast or irregular heartbeat
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • light-colored stools
  • lightheadedness
  • muscle cramps or spasms
  • muscle pain or stiffness
  • nervousness
  • numbness or tingling in the hands, feet, or lips
  • thirst
  • weakness or heaviness of the legs

Some of the side effects that can occur with hydrochlorothiazide / valsartan may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Less common
  • Cough
  • diarrhea (mild)
  • headache
  • Anxiety
  • increased sensitivity to sunlight
  • increased sweating
  • redness of the face or neck
  • reduced sexual performance or drive
Incidence not known
  • Hair loss or thinning of the hair

For Healthcare Professionals

Applies to hydrochlorothiazide / valsartan: oral tablet

Nervous system

Common (1% to 10%): Headache, fatigue, dizziness
Rare (less than 0.1%): Vertigo, tinnitus


Rare cases of interstitial nephritis have been associated with the use of HCTZ. Although HCTZ has been used to treat nephrogenic diabetes insipidus, a case report in which the drug was believed to have caused this condition has been reported.

Rare (less than 0.1%): Nausea, diarrhea, rash, acute pulmonary edema, interstitial nephritis or cystitis, anaphylaxis


Rare (less than 0.1%): Renal insufficiency, azotemia

In multiple-dose studies in hypertensive patients with stable renal insufficiency and renovascular hypertension, the use of valsartan alone had no clinically significant effects of glomerular filtrate rate, filtration fraction, creatinine clearance, or renal plasma flow. The use of HCTZ has been associated with the development of pre-renal azotemia. Pretreatment volume repletion is recommended prior to initiating therapy.


Chest pain was reported in more than 2% of patients who were taking this combination drug in controlled trials, but this incidence was not significantly different compared with the incidence of chest pain among placebo patients.

Rare (less than 0.1%): Palpitations, chest pain, angioedema
Frequency not reported: Cardiac arrhythmias (including ventricular ectopy and complete AV heart block)


Angiotensin II receptor blockade, unlike ACE inhibition, has no impact on the processing of peptides such as bradykinin and substance P, two peptides able to induce cough.

Bronchospasm, dyspnea, and epistaxis have rarely been associated with the use of this drug.

Common (1% to 10%): Cough (valsartan component)
Uncommon (0.1% to 1%): Dyspnea, acute pulmonary edema


Frequency not reported: Erythema annular centrifugum, acute eczematous dermatitis, morbilliform, leukocytoclastic vasculitis, phototoxic dermatitis, subacute cutaneous lupus erythematosus-like condition, pruritus, rash


Since HCTZ may increase total serum cholesterol by 11%, LDL lipoprotein cholesterol by 12%, and VLDL lipoprotein cholesterol levels by 50%, and may reduce insulin secretion, it should be used with caution in diabetic patients and in those with hypercholesterolemia. True glucose intolerance may develop in approximately 3% of patients. It is typically reversible within six months after discontinuation of therapy.

Hyperuricemia may be an important consideration in patients with a history of gout. Hypophosphatemia and low serum magnesium concentrations may occur, but are usually clinically insignificant except in malnourished patients.

Rare (0.01% to 0.1%): Hypokalemia, hyperkalemia, metabolic alkalosis, hyponatremia, hypomagnesemia, hypercalcemia, hyperglycemia, elevated serum uric acid levels, elevated serum cholesterol


Thiazide diuretics may increase serum cholesterol and triglycerides, resulting in an increased risk of cholesterol gallstone formation. Reports of bowel strictures associated with thiazide ingestion were reported in the 1960s (although patients in these reports were on a combination HCTZ-potassium product).

Uncommon (0.1% to 1%): Diarrhea, constipation, appetite changes, dry mouth, dyspepsia, nausea, vomiting, flatulence, pancreatitis, cholecystitis


Rare (0.01% to 0.1%): Allergic vasculitis, hemolytic anemia


Frequency not reported: Glucose intolerance, altered lipid profile

Use of valsartan alone has not been associated with significant changes in serum lipids or glucose concentrations. However, use of HCTZ may be associated with increases in total serum cholesterol by 11%, LDL lipoprotein cholesterol by 12%, and VLDL lipoprotein cholesterol levels by 50%. In addition, use of HCTZ may be associated with reduced insulin secretion. Therefore, caution is recommended when giving this combination drug to diabetic patients or those with hypercholesterolemia.

Hyperuricemia may be an important consideration in patients with a history of gout. Hypophosphatemia and low serum magnesium concentrations may occur, but are usually clinically insignificant except in malnourished patients.

A prospective study of 34 patients who received oral thiazide diuretics for 14 years without interruption revealed significantly increased average fasting blood glucose levels. Withdrawal of thiazide therapy for 7 months in 10 of the patients resulted in average reductions of 10% in fasting blood glucose and 25% in 2-hour glucose tolerance test values. A control group was not reported.


Common (1% to 10%): Back pain, muscle cramps, myalgia


Common (1% to 10%): Neutropenia
Uncommon (0.1% to 1%): Hematocrit decreased, hemoglobin decreased
Rare (0.01% to 0.1%): Immune complex hemolytic anemia
Postmarketing reports: Thrombocytopenia


Rare (less than 0.1%): Anxiety, depression, decreased libido, insomnia, paresthesias, somnolence


Rare (less than 0.1%): Impotence, dysuria


Uncommon (0.1% to 1%): Increases in hepatic enzymes (usually reversible)


Rare (less than 0.1%): Abnormal vision, idiosyncratic reactions to hydrochlorothiazide resulting in acute transient myopia and acute angle-closure glaucoma

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