Olmesartan Medoxomil

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Oct 31, 2023

Warnings


Olmesartan Risks, Warnings, and Complications


Olmesartan can cause or worsen health problems in some people. Talk to your doctor or pharmacist about taking other medications for high blood pressure if you are at an increased risk of adverse events from this drug.

  • HARM TO AN UNBORN BABY: Olmesartan can be harmful to an unborn baby if a pregnant woman takes this medicine, especially in the second or third trimester (the last 6 months of the pregnancy). Olmesartan and other drugs that act on the renin angiotensin system reduce renal perfusion and fetal renal function, resulting in oligohydramnios (low levels of amniotic fluid), underdevelopment of the baby’s lungs, skeletal deformities, and an increased risk of fetal and neonatal morbidity and death. Potential neonatal adverse effects can include underdevelopment of the skull (hypoplasia), little or no urination, low blood pressure, renal impairment, renal failure, and even death. Stop taking Benicar (olmesartan) immediately and call your doctor if you become pregnant while on this medicine. In addition, remember that olmesartan and other drugs that act on the renin angiotensin system are not suitable for children under 1 year of age as these medicines can have adverse effects on immature kidneys.

  • BLOOD PRESSURE REDUCTION: Benicar (olmesartan) can cause symptomatic hypotension (low blood pressure) in people who have an activated renin-angiotensin-aldosterone system. This includes people who are dehydrated or salt-depleted, for example, from high doses of diuretics or water pills. Your healthcare provider may start treatment at a lower dose and keep you under close medical supervision if this is the case. If you develop low blood pressure, you may need an intravenous infusion of normal saline to stabilize your blood pressure. A temporary hypotensive response does not mean you cannot take olmesartan in the future. You can probably continue on this blood pressure medicine once your blood pressure has stabilized.

  • WORSENING KIDNEY FUNCTION: Due to their inhibitory effect on the renin-angiotensin-aldosterone system, Benicar (olmesartan) and other angiotensin receptor antagonists can cause impaired renal function, resulting in oliguria (little or no urine) and/or progressive azotemia (excessive nitrogen, creatinine, and other waste products in the blood). Rarely, it can lead to acute renal failure and even death. The risk of these complications is higher if you have certain medical conditions such as severe congestive heart failure or renal artery stenosis or take other medications that can also affect your kidneys. Your provider will monitor renal function periodically while you are on olmesartan. Keep all your laboratory and medical appointments during treatment. 

  • SEVERE DIARRHEA: People taking olmesartan are at risk of developing a sprue-like enteropathy (severe chronic diarrhea and significant weight loss). This can happen several months or even years after starting this medication. Call your doctor without delay if you develop severe diarrhea during treatment with olmesartan. Your doctor may change you over to other antihypertensive medications.

  • HIGH POTASSIUM LEVELS: Olmesartan and other drugs that act on the renin angiotensin system can cause hyperkalemia (high potassium levels). The risk is higher in people with diabetes mellitus, renal insufficiency, and those taking potassium-sparing diuretics. Your healthcare provider will monitor serum potassium levels while you are on olmesartan. Do not take potassium supplements or potassium-containing salt substitutes while you are on olmesartan without talking to your doctor first.


Precautions Before Starting Olmesartan

Tell your doctor if you are allergic to olmesartan, any of the active or inactive ingredients in olmesartan tablets, any other angiotensin II receptor blocker, or any other medications. Your pharmacy can give you a list of ingredients.

Give your doctor and pharmacist a complete list of your medications, including prescription medications, over-the-counter medicines, vitamins, dietary supplements, and herbal products. This can help avoid possible drug interactions.

Give your doctor a complete medical history. Olmesartan may not be right for people with certain medical conditions such as heart failure, kidney disease, or liver disease. 

Tell your doctor if you are pregnant, could be pregnant, plan to get pregnant, or are breastfeeding.

Precautions During Use of Olmesartan

Keep all your medical and lab appointments while on Benicar (olmesartan). Your doctor will adjust your Benicar dose based on your response to the medicine. They may also order certain tests from time to time, such as serum potassium or kidney function tests.

Olmesartan can cause dizziness and lightheadedness as side effects. Arise slowly from a sitting or lying position to avoid lightheadedness due to low blood pressure. Alcohol can make these side effects worse, so avoid drinking while taking olmesartan.

If you have diarrhea or vomiting, are sweating excessively, or are not drinking enough fluids, it can lead to low blood pressure. Tell your healthcare provider if this happens during treatment with olmesartan. Your doctor may adjust your dose to prevent further blood pressure reduction. 

Tell your doctor without delay if you become pregnant while on olmesartan.

Tell all your healthcare providers you are on olmesartan before any surgery, including dental procedures.

Olmesartan Drug Interactions

Certain other drugs can affect how olmesartan works. Possible interactions with other medicines can increase the risk of severe adverse events. 

You should not take olmesartan if you have diabetes (high blood sugar) and have been prescribed a medication called aliskiren (brand names Tekturna, Tekturna HCT, Tekamlo, Valturna, in Amturnide). 

Olmesartan can also have interactions with the following medications:

  • Angiotensin-converting enzyme (ACE) inhibitors such as enalapril (Vasotec), moexipril (Univasc), benazepril (Lotensin, in Lotrel), quinapril (Accupril, in Accuretic, in Quinaretic), fosinopril, captopril (Capoten, in Capozide), lisinopril (in Prinzide), perindopril (Aceon), ramipril (Altace), and trandolapril (Mavik, in Tarka)
  • Drugs used for lowering cholesterol, such as colesevelam (Welchol) or gemfibrozil (Lopid)
  • Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (Aleve, Naprosyn) and ibuprofen (Advil, Motrin) 
  • Diuretics or water pills
  • Potassium supplements

The above list may not include all the potential drug interactions of olmesartan. Give your doctor or pharmacist a complete list of your medications, including prescription drugs, nonprescription drugs, dietary supplements, and herbal remedies. Also, tell your healthcare professional if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription medications.