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Hydrochlorothiazide / Olmesartan Dosage

Medically reviewed by Last updated on Feb 15, 2021.

Applies to the following strengths: 12.5 mg-20 mg; 12.5 mg-40 mg; 25 mg-40 mg

Usual Adult Dose for:

Additional dosage information:

Usual Adult Dose for Hypertension

Hydrochlorothiazide 12.5 to 25 mg-Olmesartan 20 to 40 mg orally once a day


  • If blood pressure is not controlled by olmesartan alone, hydrochlorothiazide may be added starting with a dose of 12.5 mg once a day; if blood pressure is not controlled by hydrochlorothiazide alone, olmesartan may be added starting with a dose of 20 mg once a day.
  • If large doses of hydrochlorothiazide have been used as monotherapy and volume depletion or hyponatremia is present, use caution when adding olmesartan as marked decreases in blood pressure may occur. Consider reducing the dose of hydrochlorothiazide to 12.5 mg before adding olmesartan.
  • May be titrated every 2 to 4 weeks.

Renal Dose Adjustments

Mild to moderate renal dysfunction (CrCl greater than 30 mL/min): No adjustment recommended
Severe renal dysfunction (CrCl 30 mL/min or lower): Not recommended

Liver Dose Adjustments

No adjustment recommended



  • FETAL TOXICITY: If pregnancy is detected, discontinue this drug as soon as possible. Drugs that act directly on the renin angiotensin system (RAS) can cause injury and death to the developing fetus.

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments


  • Dose selection for elderly patients should start at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant diseases or other drug therapy in this population.

  • Monitor serum electrolytes periodically, especially in patients with impaired renal function.

Patient advice:
  • Females of childbearing age should be informed of the consequences of exposure to this drug during pregnancy; ask these patients to report pregnancies as soon as possible.
  • Encourage patients to report any lightheadedness that may occur during treatment initiation and to stop taking this drug until consulting a physician if syncope occurs.
  • Dehydration may lead to excess blood pressure reduction; inform patients to contact their healthcare provider if they experience excessive perspiration, vomiting, or diarrhea.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.