Olmesartan medoxomil (Benicar and others)

How Medicare covers it

Part D (tablets taken at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Olmesartan medoxomil tablets treat high blood pressure (hypertension) in adults and in children six years of age and older. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, mainly strokes and heart attacks. It may be used alone or in combination with other blood pressure medicines as part of overall cardiovascular risk management.

What it is for, in depth

Olmesartan medoxomil tablets are prescribed to lower high blood pressure in adults and in children six years of age and older. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and heart attacks, although the label notes there are no controlled trials demonstrating risk reduction with olmesartan itself. The label states it may be used alone or in combination with other antihypertensive agents, and notes many patients will require more than one drug to reach blood pressure goals — so it fits either as a single starting medicine or as part of a combination, within overall cardiovascular risk management. Tablets come in 5 mg, 20 mg, and 40 mg film-coated strengths, taken once daily.

How it works

Olmesartan medoxomil is a prodrug that is converted during absorption to olmesartan, an angiotensin II receptor blocker (ARB). Angiotensin II is a hormone that tightens blood vessels and raises blood pressure. Olmesartan selectively blocks angiotensin II from attaching to the AT1 receptor in blood vessel smooth muscle, blocking its vessel-tightening effect so blood pressure falls. It does not inhibit ACE, the enzyme targeted by ACE inhibitors.

How it is taken

For adults, the usual starting dose is 20 mg by mouth once a day. If more blood pressure reduction is needed after two weeks, the dose may be increased to a maximum of 40 mg once daily; doses above 40 mg do not appear to give a greater effect, and twice-daily dosing offers no advantage. Children's doses are based on weight, starting at 10 mg or 20 mg once daily for children six years and older who weigh at least 20 kg.

Common side effects

In placebo-controlled trials in adults, the only side effect that occurred in more than 1% of patients on olmesartan and more often than with placebo was dizziness, at 3% versus 1%. Side effects were generally mild and short-lived and did not depend on dose. Facial swelling was reported in five patients. After marketing, reported effects have included vomiting, high potassium, increased creatinine, hair loss, itching, hives, muscle breakdown (rhabdomyolysis), and allergic swelling (angioedema).

Serious warnings

Olmesartan can harm an unborn baby (see the boxed warning). Blood pressure can fall too low in patients who are volume- or salt-depleted, for example those on high doses of diuretics. Kidney function can worsen in susceptible patients, rarely including acute kidney failure. Potassium levels can rise (hyperkalemia) and should be monitored. A sprue-like enteropathy — severe, chronic diarrhea with substantial weight loss — has been reported months to years after starting olmesartan; if it occurs and no other cause is found, a different blood pressure medicine should be considered.

Boxed warning

BOXED WARNING — Fetal toxicity: when pregnancy is detected, discontinue olmesartan medoxomil as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. Use during the second and third trimesters reduces fetal kidney function and increases fetal and newborn illness and death, including low amniotic fluid, lung and skull underdevelopment, low blood pressure, kidney failure, and death.

Who should be careful

Tell your clinician right away if you become pregnant while taking olmesartan, and discuss other treatment if you plan pregnancy. Do not breastfeed during treatment. Use in children under one year of age is not recommended. Patients who are volume- or salt-depleted, such as those on high-dose diuretics, should start under close medical supervision, possibly at a lower dose. Patients with impaired kidney function, diabetes, or severe heart failure need monitoring of kidney function and potassium. People with diabetes must not take aliskiren together with olmesartan.

Major interactions

Drugs that raise potassium — potassium-sparing diuretics such as spironolactone, potassium supplements, potassium-containing salt substitutes, and other renin-angiotensin blockers — can raise serum potassium further, so potassium should be monitored. NSAID pain relievers, including COX-2 inhibitors, can worsen kidney function and reduce olmesartan's blood pressure effect, especially in older, volume-depleted, or kidney-impaired patients. Combining two renin-angiotensin blockers (ARBs, ACE inhibitors, or aliskiren) raises the risks of low blood pressure, high potassium, and kidney failure; aliskiren must not be combined with olmesartan in patients with diabetes. Lithium levels can rise to toxic levels. Take olmesartan at least 4 hours before colesevelam.

Why it is in its tier

Olmesartan is a generic medicine (the generic form of olmesartan medoxomil), and its most common (modal) tier in the 2027 listings is Tier 1, in 84.91% of listing plans, with 97.78% of plans listing it. Tier 1 is the preferred generic tier, with the lowest copays — often $0 to $15. On the CMS dashboard for 2024, average spending was $75.80 per beneficiary — a program average cost figure, not a patient copay. Plans set their own tiers, so verify your plan's placement.

Sources

• OLMESARTAN MEDOXOMIL TABLET, FILM COATED [GLENMARK PHARMACEUTICALS INC., USA] — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus — Olmesartan

What official patient guides say

Olmesartan comes as a tablet to take by mouth, usually once a day with or without food, at around the same time every day to help you remember it. If you miss a dose, take it as soon as you remember it, but if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule; do not take a double dose to make up for a missed one. Keep taking it even if you feel well, and do not stop taking it without talking to your doctor. Store it in the container it came in, tightly closed and out of reach of children, at room temperature and away from excess heat and moisture (not in the bathroom).

Source: MedlinePlus — Olmesartan

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is 0.08005 per unit (OLMESARTAN MEDOXOMIL 20 MG TAB) — about nan for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-08

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 5,373 list Olmesartan medoxomil (Benicar and others) — 97.8% of plans. Most of those plans put it on Tier 1: 4,562 plans, 84.9% of the plans that list it. Other plans place it on Tier 6 (655 plans), Tier 2 (151 plans) or Tier 5 (3 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 1; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 1; Aetna Medicare Value Plus (PPO) puts it on Tier 1. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.