Olmesartan and olmesartan medoxomil are not two different blood pressure drugs. They are two stages of the same one. The tablet you swallow contains olmesartan medoxomil, and the olmesartan that actually lowers your blood pressure appears only after your body changes it.1PubMed. The new oral angiotensin II antagonist olmesartan medoxomil: a concise overview The extra word is a delivery tool built into the pill, not a second ingredient with its own effect, which is why labels and doctors often use the two names interchangeably.
What the Medoxomil Part Does
Olmesartan medoxomil is a prodrug, meaning it is built to be converted into its active form inside the body.2PubMed. Olmesartan Here, the conversion is possible because the molecule carries a breakable chemical link attached to the olmesartan.3PubMed. A review of the structural and functional features of olmesartan medoxomil, an angiotensin receptor blocker In the intestine, the body snaps that link off and leaves olmesartan behind.4PubMed. A review of the structural and functional features of olmesartan medoxomil, an angiotensin receptor blocker The medoxomil portion is a temporary carrier and plays no part in how the drug lowers blood pressure. You never need to take plain olmesartan separately, because the tablet supplies it.
The carrier exists because plain olmesartan is poorly absorbed. In lab models of the gut lining, the medoxomil form was taken up several times more readily than plain olmesartan.5PubMed. Conversion of Olmesartan to Olmesartan Medoxomil, A Prodrug that Improves Intestinal Absorption, Confers Substrate Recognition by OATP2B1 Adding medoxomil lets more of each dose reach your bloodstream. The same strategy is used in a few other approved medicines, including the blood pressure drug azilsartan medoxomil.6PubMed. Medoxomil Prodrug Strategies
Once the body clips the medoxomil piece off, it is no longer attached to the drug. It becomes a small compound that the body quickly clears,7PubMed. The pharmacokinetic and metabolic profile of olmesartan medoxomil limits the risk of clinically relevant drug interaction so it does not build up from daily use.
If you see both names on different documents, that is not two prescriptions or a duplicate. It is one tablet described at two stages.
What Happens After You Swallow the Pill
Olmesartan medoxomil is rapidly and completely converted to olmesartan.8PubMed. Olmesartan Symptoms and gut damage are expected to recover once the drug is stopped.9PubMed Central. Severe spruelike enteropathy associated with olmesartan The change happens while the drug is being absorbed from the digestive tract,10Pfizer. OLMETEC® so what circulates in your blood is olmesartan, not olmesartan medoxomil.11PubMed. The new oral angiotensin II antagonist olmesartan medoxomil: a concise overview Food does not change how much of the drug you absorb, so you can take it with or without meals.12Pfizer. OLMETEC®
Olmesartan reaches its highest blood level about 1 to 2 hours after a dose.13U.S. Food and Drug Administration. BENICAR (olmesartan medoxomil) tablets From there, the level falls by half about every 13 hours.14U.S. Food and Drug Administration. BENICAR (olmesartan medoxomil) tablets Because the level only halves that slowly, a good amount remains when the next daily dose is due, which is why the effect holds through the night and early morning. With daily use the levels settle into a steady pattern over several days.
Taking it at the same time each day keeps those levels even. If you miss a dose, follow your label or ask your pharmacist rather than doubling up.
About 99% of olmesartan in the blood rides on blood proteins.15U.S. Food and Drug Administration. BENICAR (olmesartan medoxomil) tablets Only a tiny free fraction is available to act at any moment, and the protein-bound part acts as a reservoir.
Once formed, olmesartan is not broken down further by the body.16PubMed. The new oral angiotensin II antagonist olmesartan medoxomil: a concise overview It leaves largely unchanged through both urine and bile.17PubMed. Multiple human isoforms of drug transporters contribute to the hepatic and renal transport of olmesartan, a selective antagonist of the angiotensin II AT1-receptor Roughly 35% to 50% of the absorbed amount exits in urine and the rest in stool.18DailyMed. Benicar- olmesartan medoxomil tablet, film coated
Many drugs are processed by liver enzymes that other medicines can speed up or slow down. Olmesartan skips that step, so it has a limited risk of clashing with other drugs through liver metabolism.19PubMed. The pharmacokinetic and metabolic profile of olmesartan medoxomil limits the risk of clinically relevant drug interaction Still, tell your pharmacist about all your medicines and supplements, since other kinds of interactions exist.
How Olmesartan Lowers Blood Pressure
Olmesartan blocks the docking site for angiotensin II, a hormone that tightens blood vessels.20Journal of Pediatric Urology. NRA-Olmesartan Drugs that work this way are called angiotensin receptor blockers, or ARBs, a term you may see on drug information sheets. With the hormone blocked, vessels relax and blood pressure drops. The full effect builds over days to weeks, so a reading shortly after the first dose is not the whole picture, and most people do not feel the drug working.
ARBs are often confused with ACE inhibitors. Both target the same hormone system, but at different steps: ACE inhibitors stop the hormone being made, while ARBs block where it acts. Unlike ACE inhibitors, olmesartan does not affect a body chemical linked to the dry cough some ACE inhibitors cause.21DailyMed. OLMESARTAN MEDOXOMIL tablet, film coated Doctors sometimes switch people from an ACE inhibitor to an ARB if cough is a problem. Both share the same pregnancy warning described below.
Olmesartan forms tight, slow-to-release bonds with the receptor.22PubMed. Sartan-AT1 receptor interactions: in vitro evidence for insurmountable antagonism and inverse agonism Among common ARBs it ranks second only to candesartan in how tightly it binds, and well ahead of losartan.23PubMed. Sartan-AT1 receptor interactions: in vitro evidence for insurmountable antagonism and inverse agonism
How Well It Works Compared With Similar Drugs
At starting doses, olmesartan lowered the bottom blood pressure number by about 11.5 points, versus about 8 to 10 points for losartan, valsartan and irbesartan.24PubMed Central. Comparative Efficacy of Olmesartan, Losartan, Valsartan, and Irbesartan in the Control of Essential Hypertension Over 24 hours it lowered the top number by about 12.5 points, more than losartan and valsartan and similar to irbesartan.25PubMed Central. Comparative Efficacy of Olmesartan, Losartan, Valsartan, and Irbesartan in the Control of Essential Hypertension About 50% more people reached a reading below 140/90 on olmesartan than on losartan or valsartan.26American Journal of Hypertension. Blood pressure goal attainment: comparative efficacy of olmesartan medoxomil, losartan potassium, valsartan, and irbesartan In another comparison, olmesartan 20 mg lowered 24-hour blood pressure more than candesartan 8 mg, with most of the effect within 1 to 2 weeks.27PubMed. Olmesartan compared with other angiotensin II receptor antagonists: head-to-head trials
These studies compared standard starting doses, and higher doses of other ARBs can close the gap. Your own best drug depends on your response, and the target your doctor sets varies with age and other conditions. Home readings taken at the same time of day, as your doctor advises, say more about how your pill is doing than a single clinic reading. Don’t switch drugs on your own; talk through results and side effects with your doctor. Many guidelines recommend two drugs together when blood pressure starts at 150 or higher, often in a single combined pill.28PubMed Central. The Efficacy of Single-pill Combination of Olmesartan Medoxomil and Amlodipine Besylate on Office Blood Pressure in Hypertensive Patients who did not Respond to Amlodipine Besylate Monotherapy
Olmesartan is often paired with amlodipine, and the ARB may offset the ankle swelling amlodipine can cause.29PubMed Central. Critical appraisal of amlodipine and olmesartan medoxomil fixed-dose combination in achieving blood pressure goals The two address different parts of the problem: the ARB blocks the hormone, while amlodipine relaxes vessel walls directly through a different route.
Combination pills list both ingredients, such as olmesartan medoxomil and amlodipine, and the medoxomil part works the same way as in the single pill. When a refill looks different, check the strength of each ingredient.
Safety Warnings to Know
Do not take olmesartan if you are pregnant; it can cause death or serious injury to the baby in the last 6 months of pregnancy.30MedlinePlus. Olmesartan: MedlinePlus Drug Information These drugs reduce the baby’s kidney function, which can lower the fluid around the baby and harm lung and skull development.31DailyMed. OLMESARTAN MEDOXOMIL tablet, film coated Harm has generally not been seen when exposure was limited to the first trimester, though the drug should still be stopped as soon as pregnancy is known.32DailyMed. Benicar (olmesartan medoxomil) tablets If you find out you are pregnant, stop and call your doctor right away.
The doctor will usually move you to a medicine considered safer. If you are planning a pregnancy, tell your doctor before trying to conceive so a safer medicine can be arranged.
Olmesartan can rarely cause a gut injury resembling celiac disease, with severe chronic diarrhoea and weight loss.33PubMed Central. Olmesartan-Induced Sprue Like Enteropathy It can start years after beginning the drug.34PubMed Central. Olmesartan-Induced Sprue Like Enteropathy
The pattern is watery diarrhoea that does not go away over weeks, often with weight loss, tiredness, and sometimes nausea or belly discomfort. Most diarrhoea in people taking this pill has another cause, such as a stomach bug, so this is a possibility to raise, not an assumption. Ongoing unexplained diarrhoea while on olmesartan is worth raising with your doctor, and a note of when it began relative to starting the pill helps.
The reaction is easily missed. It looks like celiac disease, though a gluten-free diet does not fix it, and because it appears years later, people rarely suspect a long-used pill. Mention olmesartan by name if a doctor investigates your diarrhoea. If it is confirmed, doctors typically stop the drug and switch to a different blood pressure medicine, and symptoms usually settle over time. Never stop the drug without medical advice.
Brand Names and Generic Labels
Benicar is a US brand of olmesartan medoxomil tablets.35U.S. Food and Drug Administration. BENICAR (olmesartan medoxomil) tablets Olmetec is a brand name used in other countries.36Pfizer. OLMETEC® Generic tablets are labelled olmesartan medoxomil.37DailyMed. OLMESARTAN MEDOXOMIL tablet, film coated A pharmacy switch between these is a switch of maker, not of active drug.
When the name on your label changes, check that the strength in milligrams matches your prescription. Generic makers must use the same active ingredient at the same strength, but the color, shape, markings, and inactive fillers can differ. A refill that looks different is common after a pharmacy changes its supplier and does not mean the dose changed. Because the fillers can differ, mention any known allergy to a dye or filler to your pharmacist.
Look-alike names deserve a closer read. Combination products add a second drug name, such as hydrochlorothiazide or amlodipine. Azilsartan medoxomil is a different drug despite sharing the medoxomil ending, so confirm the first word, not just the ending.