What is Benicar HCT?

Benicar HCT (olmesartan medoxomil-hydrochlorothiazide) tablets, for oral use, is a combination of an angiotensin II receptor blocker (ARB) and a thiazide diuretic used to treat high blood pressure (hypertension).

Common side effects of Benicar HCT include nausea, hyperuricemia, dizziness, upper respiratory tract infection, chest pain, back pain, swelling in extremities, spinning sensation (vertigo), abdominal pain, indigestion, upset stomach, diarrhea, SGOT increased, GGT increased, SGPT increased, hyperlipemia, creatine phosphokinase increased, high blood sugar (hyperglycemia), joint pain, muscle pain, cough, rash, and blood in urine.

Serious side effects of Benicar HCT include changes in kidney function. electrolyte imbalance, and worsening or activation of systemic lupus erythematosus (SLE).

Drug interactions of Benicar HCT include nonsteroidal anti-inflammatory drugs (NSAIDs) including selective COX-2 inhibitors because it may result in kidney problems, including kidney failure.

  • Combining Benicar HCT with alcohol, barbiturates, or narcotics may cause dizziness on standing.
  • Dosage adjustment of antidiabetic drugs (oral and insulin) may be required when taken with Benicar HCT.
  • Benicar HCT combined with other antihypertensive drugs may have an additive effect and can increase side effects.
  • Cholestyramine and colestipol resins impair the absorption of hydrochlorothiazide.
  • Corticosteroids taken with Benicar HCT can cause ACTH-intensified electrolyte depletion, particularly low blood potassium (hypokalemia).
  • Taking Benicar HCT with skeletal muscle relaxants may cause increased responsiveness to the muscle relaxant.
  • Lithium should not generally be given with diuretics because diuretics reduce the renal clearance of lithium and add a high risk of lithium toxicity.

When pregnancy is detected, discontinue Benicar HCT as soon as possible. It may cause birth defects or fetal death.

It is unknown if olmesartan passes into breast milk. Hydrochlorothiazide passes into breast milk. Because of the potential for adverse effects on the nursing infant, breastfeeding is not recommended while using Benicar HCT.

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.

What are the serious side effects of Benicar HCT?

Benicar HCT may cause serious side effects including:

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

What are the common side effects of Benicar HCT?

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 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.

Side effects of Benicar HCT list for healthcare professionals

The following adverse reactions with Benicar HCT are described elsewhere:

Clinical Trials Experience

In a placebo-controlled, factorial clinical trial of olmesartan medoxomil (2.5 mg to 40 mg) and hydrochlorothiazide (12.5 mg to 25 mg), the following adverse reactions reported in Table 1 occurred in > 2% of patients, and more often on the olmesartan medoxomil and hydrochlorothiazide combination than on placebo.

Table 1: Adverse Reactions in a Factorial Trial of Patients with Hypertension

Olmesartan/ HCTZ
(N=247) (%)
(N=125) (%)
(N=88) (%)
(N=42) (%)
Nausea 3 2 1 0
Hyperuricemia 4 0 2 2
Dizziness 9 1 8 2
Upper Respiratory Infection 7 6 7 0

Other adverse reactions that have been reported with an incidence of greater than 1.0%, whether or not attributed to treatment, in the more than 1200 hypertensive patients treated with olmesartan medoxomil and hydrochlorothiazide in controlled or open-label trials are listed below.


Other adverse reactions that have been reported with hydrochlorothiazide are listed below:

Clinical Laboratory Test Findings

  • Creatinine/blood urea nitrogen (BUN): Minor elevations in creatinine and BUN occurred in 1.7% and 2.5% respectively, of patients taking Benicar HCT and 0% and 0% respectively, given placebo in controlled clinical trials.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of BENICAR HCT. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

  • Body as a Whole: Asthenia
  • Gastrointestinal: Vomiting
  • Metabolic: Hyperkalemia
  • Musculoskeletal: Rhabdomyolysis
  • Skin and Appendages: Alopecia, pruritus

Data from one controlled trial and an epidemiologic study have suggested that high-dose olmesartan may increase cardiovascular (CV) risk in diabetic patients, but the overall data are not conclusive.

Treatment & Diagnosis

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Report Problems to the Food and Drug Administration

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 11/12/2021
FDA Prescribing Information

Professional side effects, drug interactions, and addiction sections courtesy of the U.S. Food and Drug Administration.