Benicar HCT (olmesartan medoxomil-hydrochlorothiazide)

Medically Reviewed on 11/8/2021

What is Benicar HCT, and what is it used for?

Benicar HCT (olmesartan medoxomil-hydrochlorothiazide) is a combination of an angiotensin II receptor antagonist and a thiazide diuretic (water pill) used to treat the symptoms of high blood pressure (hypertension).

Benicar HCT may be used alone or with other medications. It is not known if Benicar HCT is safe and effective in children.

What are the side effects of Benicar HCT?



When pregnancy is detected, discontinue Benicar HCT as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus.

Benicar HCT may cause serious side effects including:

Get medical help right away, if you have any of the symptoms listed above.

The most common side effects of Benicar HCT include:

Tell the doctor if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Benicar HCT. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Is Benicar HCT addictive?

No information provided

What is the dosage for Benicar HCT?

  • The recommended starting dose of Benicar HCT is 40/12.5 mg once daily in patients whose blood pressure is not adequately controlled with olmesartan monotherapy. Dose can be titrated up to 40 /25 mg if necessary.
  • The recommended starting dose of Benicar HCT is 20/12.5 mg once daily in patients whose blood pressure is not adequately controlled with HCT monotherapy or who experience dose-limiting adverse reactions with hydrochlorothiazide. Dose can be titrated up to 40 /25 mg if necessary.
  • Patients titrated to the individual components (olmesartan and hydrochlorothiazide) may instead receive the corresponding dose of Benicar HCT.

What drugs interact with Benicar HCT?

Agents Increasing Serum Potassium

  • Coadministration of Benicar HCT with other drugs that raise serum potassium levels may result in hyperkalemia. Monitor serum potassium in such patients.


  • Increases in serum lithium concentrations and lithium toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists or hydrochlorothiazide. Monitor serum lithium levels during concomitant use.

Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors )

Olmesartan Medoxomil
  • In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, co-administration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including olmesartan medoxomil) may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving olmesartan medoxomil and NSAID therapy.
  • The antihypertensive effect of angiotensin II receptor antagonists, including olmesartan medoxomil may be attenuated by NSAIDs including selective COX-2 inhibitors.
  • In some patients the administration of a NSAID can reduce the diuretic, natriuretic, and antihypertensive effects of thiazide diuretics. Therefore, monitor blood pressure closely.

Dual Blockade of The Renin Angiotens in System

  • Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy.
  • Most patients receiving the combination of two RAS inhibitors do not obtain any additional benefit compared to monotherapy. In general, avoid combined use of RAS inhibitors. Closely monitor blood pressure, renal function and electrolytes in patients on Benicar HCT and other agents that affect the RAS.
  • Do not co-administer aliskiren with Benicar HCT in patients with diabetes. Avoid use of aliskiren with Benicar HCT in patients with renal impairment (GFR < 60 ml/min).

Colesevelam Hydrochloride

  • Concurrent administration of bile acid sequestering agent colesevelam hydrochloride reduces the systemic exposure and peak plasma concentration of olmesartan. Administration of olmesartan at least 4 hours prior to colesevelam hydrochloride decreased the drug interaction effect. Consider administering olmesartan at least 4 hours before the colesevelam hydrochloride dose.

Use of Hydrochlorothiazide with Other Drugs

  • When administered concurrently the following drugs may interact with thiazide diuretics:
    • Antidiabetic drugs (oral agents and insulin): Dosage adjustment of the antidiabetic drug may be required.
    • Ion exchange resins: Staggering the dosage of hydrochlorothiazide and ion exchange resins (e.g., cholestyramine, colestipol) such that hydrochlorothiazide is administered at least 4 hours before or 4 – 6 hours after the administration of resins would potentially minimize the interaction.
    • Corticosteroids, ACTH: Intensified electrolyte depletion, particularly hypokalemia.


How to Lower Blood Pressure: Exercise and Tips See Slideshow

Benicar HCT contraindications, and pregnancy and breastfeeding safety

  • Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity, and death. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death.
  • It is not known whether olmesartan is excreted in human milk. Because of the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue Benicar HCT, taking into account the importance of the drug to the mother.


Benicar HCT (olmesartan medoxomil-hydrochlorothiazide) is a combination of an angiotensin II receptor antagonist and a thiazide diuretic (water pill) used to treat the symptoms of high blood pressure (hypertension). Benicar HCT can cause fetal harm when used during pregnancy. Serious side effects include muscle pain, tenderness or weakness, fever, unusual tiredness, dark-colored urine, eye pain, vision problems, lightheadedness, yellowing of the skin or eyes (jaundice), easy bruising, and others.

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 11/8/2021
All sections courtesy of the U.S. Food and Drug Administration