Olmesartan — what it is and how to use it safely
Olmesartan is an angiotensin II receptor blocker (ARB) often prescribed for high blood pressure. If your doctor suggested olmesartan, you probably want straightforward facts: how it works, common side effects, and what to watch for. This page gives clear, practical points so you can talk to your prescriber with confidence.
How olmesartan works and when it's used
Olmesartan blocks a hormone that tightens blood vessels, so your arteries relax and blood pressure falls. Doctors use it for primary hypertension alone or with other drugs. Typical starting doses vary: adults often start at 20 mg once daily, and doctors may raise it to 40 mg if needed. If you have kidney problems or take certain medicines, your prescriber may start lower.
Not everyone should take olmesartan. It's not for pregnant people — ARBs can harm a fetus. If you have severe kidney artery narrowing, certain electrolyte problems, or a history of angioedema with ARBs, tell your doctor first.
Side effects, risks, and practical tips
Most people tolerate olmesartan well. Common effects include dizziness (especially when standing up), headache, and fatigue. A rare but serious issue is sprue‑like enteropathy — persistent severe diarrhea and weight loss that can appear months after starting the drug. If you get unexplained chronic diarrhea, see your doctor and mention olmesartan.
Olmesartan can raise potassium and affect kidney function. Your doctor will likely check blood tests after starting or changing dose. If you use potassium supplements, salt substitutes, or potassium‑sparing diuretics, be extra careful — those raise potassium too.
Drug interactions matter. Avoid combining olmesartan with other ARBs or ACE inhibitors unless a specialist recommends it. Certain painkillers (NSAIDs) can reduce how well olmesartan works and may increase kidney risk when used long term.
Practical tips: take olmesartan at the same time each day, with or without food. If you miss a dose, skip it and take the next scheduled dose — don’t double up. Keep regular BP checks, and report sudden swelling, trouble breathing, fainting, or severe diarrhea right away.
Thinking about alternatives? Other ARBs like losartan, valsartan, and candesartan work similarly. ACE inhibitors (like lisinopril) are another class used for blood pressure, but they have different side effects and are often avoided in pregnancy.
Buying and safety: get prescriptions from licensed pharmacies and keep follow‑up appointments. If you order medication online, choose verified pharmacies and avoid suspiciously low prices or no-prescription offers.
If you’re unsure whether olmesartan is right for you, ask your clinician about benefits, possible side effects, and simple lifestyle moves—like cutting salt, losing a few kilos, and exercising—that help blood pressure and may let you use lower doses of medicine.