Benicar is a prescription blood pressure medication manufactured by Japanese drugmaker Daiichi Sankyo. Its active ingredient is olmesartan medoxomil. The medication belongs to the angiotensin II receptor blocker, or ARB, drug class and works by blocking the hormone that tightens blood vessels.

Benicar Pills
Benicar Facts
  1. Dosage: 10 mg (children), 20 mg, 40 mg
  2. Used To Treat: Hypertension (high blood pressure)
  3. Related Drugs: Benicar HCT, Azor, Tribenzor, generics
  4. Manufacturer: Daiichi Sankyo
  5. Black Box Warnings: Fetal toxicity
  6. FDA Approval: 2002

The U.S. Food and Drug Administration first approved brand name Benicar in 2002 to treat high blood pressure. Then in 2003, it approved Benicar HCT — a drug that adds olmesartan with hydrochlorothiazide, a thiazide diuretic.

In clinical trials, one 20 mg dose of olmesartan reduced blood pressure by about 10/6 mmHg and 40 mg reduced it by about 12/7 mmHg.

Millions of Americans use Benicar and its generics each year.

Hypertension Diagram
The Centers for Disease Control and Prevention defines blood pressure as the force of blood against the artery walls as it circulates through the body.

Olmesartan medoxomil was the 164th most-prescribed drug in the United States in 2017 with 3,805,975 prescriptions, according to the U.S. Department of Health and Human Services’ most recent Medical Expenditure Panel Survey data.

Health providers wrote 1,764,804 prescriptions for olmesartan medoxomil-hydrochlorothiazide in 2017.

What Does Benicar Treat?

Benicar is indicated for the treatment of hypertension, also known as high blood pressure. It is used to lower blood pressure.

Blood pressure rises as vessels constrict. While it’s normal for blood pressure to rise and fall throughout the day, health problems can develop for individuals whose blood pressure remains high for a longer period of time.

When left unchecked, elevated blood pressure levels greatly increase a person’s risk for heart disease and stroke, the first and third leading causes of death in the United States, respectively. High blood pressure usually has no accompanying symptoms, so many people are unaware that there’s even a problem.

The Centers for Disease Control and Prevention estimated that 75 million adults are dealing with high blood pressure in the United States. It affects approximately one in every three adults.

Only half of those individuals are controlling their condition. Seven in 10 of those adults are controlling their blood pressure with medication. These individuals are sometimes prescribed a medication such as Benicar or one of its sister drugs containing the ingredient olmesartan.

For patients suffering from high blood pressure, taking a medication, such as Benicar, can reduce the risk of heart attack and stroke.

Additional approved indications include:
  • Angina
  • Heart failure
  • Diabetic kidney disease

Who Does Not Benefit from Treatment?

Benicar can result in complications for fetuses, especially in the second and third trimesters, and some of these complications can be fatal. Also, the drug has not been tested on children under 1. Other individuals can experience
adverse reactions when taking Benicar.

Benicar is not recommended for the following people:
  • Pregnant women
  • Nursing mothers
  • Children under one year of age
  • Patients with blood volume or salt depletion
  • Patients with narrowing of arteries

Benicar Side Effects

Common Benicar side effectsinclude headache, flu-like symptoms and diarrhea. Serious and less common side effects include elevation of liver enzymes, joint pain and swelling.

In 2013, the FDA released a safety announcement warning the public that Benicar has the potential to cause intestinal problems known as sprue-like enteropathy. Symptoms of drug-induced sprue-like enteropathy include severe, chronic diarrhea and substantial weight loss within months to years after beginning use of the medication.

Benicar can also result in fetal toxicity and is not recommended for women who are pregnant, especially in the second and third trimesters.

Common Side Effects
  • Back pain
  • Bronchitis
  • Increase of creatinine phosphokinase (CPK)
  • Diarrhea
  • Headache
  • Blood in urine
  • High blood sugar
  • Elevated triglyceride levels (fat in the blood)
  • Flu-like symptoms
  • Inflammation of pharynx or back of throat
  • Inflammation of mucous membrane inside the nose
  • Sinusitis
Less Common Side Effects
  • Chest pain
  • Peripheral edema
  • Vertigo
  • Abdominal pain
  • Indigestion
  • diarrhea/abdominal pain
  • Nausea
  • Heart palpitations
  • Very high levels of cholesterol in blood
  • Abnormally high concentration of fats in blood
  • Excess of uric acid in blood
  • Joint pain
  • Arthritis
  • Muscle pain
  • Rash
Rare Side Effects
  • Facial swelling
  • Swelling below the skin’s surface
  • Small decreases in hemoglobin and hematocrit
  • Infrequent elevations of liver enzymes and/or serum bilirubin
Post-Marketing (Voluntarily Reported) Side Effects
  • Physical weakness/lack of energy
  • Angioedema
  • Life-threatening allergic reaction
  • Vomiting
  • High blood potassium
  • Rapid destruction of skeletal muscle
  • Acute kidney failure
  • Increased blood creatinine levels
  • Hair loss
  • Severe itching of skin
  • Hives

Black Box Warning – Fetal Toxicity

black box warning appears on a prescription drug’s label when the FDA wants to call attention to serious or life-threatening risks associated with its use. Benicar (olmesartan medoxomil) contains one of these warnings for fetal toxicity. The label says Benicar should be discontinued as soon as possible after pregnancy is detected. It further warns that drugs that act directly on the physiological system that regulates blood pressure, such as Benicar, can cause injury and death to the developing fetus.

The label says the risks are greater during the second and third trimesters. The risks include reduction of fetal renal function and increase in fetal and neonatal death.

The potential for a deficiency in amniotic fluid can result in fetal lung underdevelopment and skeletal deformations.

Potential neonatal adverse effects include:
  • Skull underdevelopment
  • Failure of kidneys to produce urine
  • Low blood pressure
  • Kidney failure
  • Death

Benicar Dosages

Benicar comes in tablet form in three different prescription strengths: 5 milligrams (yellow/round pill), 20 milligrams (white/round pill), 40 milligrams (white/oval). This drug can be taken with or without food, and it can also be administered with a diuretic and/or other antihypertensive medications.

Benicar 5mg
5 mg (yellow/round pill) dosage
Benicar 20mg
20 mg (white/round pill) dosage
Benicar 40mg
40 mg (white/oval) dosage
Dosage Information for Adults
  • Recommended starting dosage of 20 milligrams once daily
  • Patients requiring further blood pressure reduction after two weeks of taking Benicar may increase the dose to 40 milligrams.
  • Doses above 40 milligrams have not been shown to have any greater effect in patients.
  • Twice-daily dosages do not appear to offer any advantage over the same total dose taken once daily.
Dosage Information for Children
  • Dosing must be individualized
  • Recommended starting dosage in children 6 to 16 years of age and weighing 44 to 77 pounds is 10 milligrams once daily
  • Patients requiring a further reduction in blood pressure after two weeks of taking Benicar may increase the dose to a maximum of 20 milligrams once daily for those weighing under 77 pounds
  • Patients requiring a further reduction in blood pressure after two weeks of taking Benicar may increase the dose to a maximum of 40 milligrams for those weighing over 77 pounds
  • For children who cannot swallow pills, Benicar may be taken as a suspension.

Drug Interactions with Benicar

It is possible for Benicar to cause adverse reactions when taken concurrently with certain drugs (both prescription and nonprescription). These adverse reactions may include unfavorable side effects and/or lessened effectiveness of Benicar or the other drugs.

Drugs that Interact with Benicar
Aliskiren (Brand Name – Tekturna):
It is recommended that Benicar is not given in conjunction with aliskiren (antihypertensive drug) in patients with diabetes.
NSAIDs (Selective COX-2 Inhibitors):
Initial dose of 10 mg or 20 mg/day. After 1 week at 10 mg, increase to 20 mg.
Dual Blockade of the Renin-Angiotensin System (RAS):
Taking Benicar with other ARBs, ACE (angiotensin-converting enzyme) inhibitors (such as Captopril, Ramipril, Lisinopril, Quinapril and others) or aliskiren is associated with increased risks of low blood pressure, high potassium and changes in kidney function.
Colesevelam Hydrochloride (Brand Name – Welchol):
Taking colesevelam hydrochloride with Benicar reduces its effectiveness. It is recommended that olmesartan is taken at least four hours prior to taking a dose of colesevelam hydrochloride in order to decrease the effect of the drugs’ interaction.

Mayo Clinic Study Confirms Olmesartan-Induced Enteropath

Twenty-two patients in a study to determine the link between olmesartan and unexplained sprue-like enteropathy were seen at the Mayo Clinic between August 2008 and August 2011. Olmesartan is an active ingredient in Benicar.

To be included in the study, patients had to first have chronic diarrhea (lasting more than four weeks) while taking olmesartan. Second, the cause of the enteropathy could not be explained by another disorder, such as celiac disease; and finally, discontinuing the drug had to result in clinical improvement.

Mayo Clinic’s 2012 Report

In 2012, Mayo Clinic researchers published a case series of sprue-like enteropathy associated with patients’ use of olmesartan.

2012 Results:
  • The 22 subjects involved in the series presented similar clinical results to individuals of 23 adverse event reports identified by the FDA through its FDA’s Adverse Event Report System (FAERS).
  • Of the 22 patients from 17 states treated by the Mayo Clinic between the years of 2008 to 2011, 14 required hospitalization with weight losses averaging almost 40 pounds, and one patient losing a total of about 125 pounds.
  • None of the patients responded to gluten free diets (used for celiac disease sufferers), but all of the patients shared one similarity; they were all taking daily doses of olmesartan ranging from 10 to 40 mg.
  • When olmesartan was discontinued, the patients’ symptoms improved and they all experienced some degree of weight gain.

Mayo Clinic’s 2013 Report

In May 2013, an article was published describing patients with villous atrophy and negative blood tests for celiac disease.

2013 Results:
  • The article reported that some patients without definitive causes for villous atrophy were categorized as having unclassified sprue.
  • It was later discovered that some of these patients had villous atrophy associated with their use of olmesartan.

Olmesartan-induced enteropathy was further investigated and confirmed by Mini-Sentinel and CMS Medicare assessments, which showed that at a two-year minimum exposure to the ARB class of drugs, patients using olmesartan had a higher rate of subsequent celiac disease diagnoses than users of other ARBs.

FDA-Initiated Label Change and Warning Letter to Benicar Manufacturer

Although olmesartan-containing drugs such as Benicar had been on the market for over a decade, the FDA did not issue its safety announcement about the potential for occurrences of sprue-like enteropathy until 2013. This decision came following its evaluation of FAERS, the Mayo Clinic case series and information from the CMS database. The FDA also ordered the drug manufacturer to change its labeling on the blood pressure medication to include a warning about this.

In premarketing clinical trials, the incidence of adverse effects reported by Daiichi Sankyo related to olmesartan was similar to those of placebo, and the only negative effect linked directly to olmesartan with greater frequency than the placebo, as reported in the prescribing information, was dizziness. While millions of individuals have been prescribed olmesartan over the last several years, reports of severe gastrointestinal reactions associated with its use are claimed to not have surfaced until later in 2012.

Less than a year after the FDA ordered the label change for Benicar and other drugs containing olmesartan, patients who had suffered sprue-like enteropathy began filing Benicar lawsuits. Daiichi Sankyo, Benicar’s manufacturer, agreed in August 2017 to settle Benicar claims from about 2,300 plaintiffs in cases for $300 million.

In 2006, the U.S. Department of Health & Human Services (DOH) submitted a warning letter to Sankyo Pharma Inc. through its Division of Drug Marketing, Advertising and Communications (DDMAC). The letter requested that Sankyo immediately cease its promotion of certain sales and marketing materials that contained unsubstantiated effectiveness and superiority claims, and omitted or minimalized information on the risks associated with the use of Benicar.

The omitted or minimalized risk information included:
  • Serious pregnancy-related risks
  • Renal artery stenosis (narrowing of arteries that carry blood to one or both of the kidneys) precautions
  • Risk information regarding the use of Benicar HCT in patients with impaired liver function or systemic lupus erythematosus (the most common form of lupus characterized by extreme fatigue and joint pain)
  • Lithium interactions

In addition to the marketing warnings, Daiichi Sankyo faced kickback allegations. The U.S. Justice Department accused Daiichi Sankyo of paying doctors to prescribe Benicar. Daiichi Sankyo paid $39 million to settle the criminal case.

Please seek the advice of a medical professional before making health care decisions.

Related Pages
Kristin Compton
Written By Kristin Compton Writer

Kristin Compton's background is in legal studies. She worked as a paralegal before joining Drugwatch as a writer and researcher. She was also a member of the National Association of Legal Assistants. A mother and longtime patient, she has firsthand experience of the harmful effects prescription drugs can have on women and their children. Some of her qualifications include:

  • Bachelor of Arts in Legal Studies | Pre-Law from University of West Florida
  • Past employment with The Health Law Firm and Kerrigan, Estess, Rankin, McLeod & Thompson LLC
  • Personal experience battling severe food allergies, asthma and high-risk pregnancies
Edited By
Kevin Connolly
Kevin Connolly Managing Editor

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