Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Consult your doctor or pharmacist for advice specific to your medications.
If you accidentally took two olmesartan pills, stay calm. A single accidental double dose of olmesartan (Benicar) is unlikely to cause serious harm. Clinical trials tested 80 mg daily with a safety profile similar to placebo, and the FDA-approved maximum is 40 mg. Watch for dizziness or lightheadedness, skip your next scheduled dose, and contact your doctor if symptoms develop.
How olmesartan works (and why doubling is usually manageable)
Olmesartan is an ARB (angiotensin II receptor blocker). It lowers blood pressure by blocking a hormone called angiotensin II that tightens blood vessels. When that hormone is blocked, your blood vessels relax and blood pressure comes down.
The standard prescribed doses are 20 mg or 40 mg once daily. Here is the important part: a pooled analysis of seven clinical trials involving 3,055 patients confirmed that olmesartan at doses from 2.5 to 80 mg per day had a tolerability profile similar to placebo.
This gives olmesartan a wide safety margin for an accidental double dose.
What your double dose looks like
| Your prescribed dose | You accidentally took | Max approved daily dose | How it compares |
|---|---|---|---|
| 20 mg | 40 mg | 40 mg | At the maximum approved dose |
| 40 mg | 80 mg | 40 mg | Studied in clinical trials with placebo-like safety |
If you doubled a 20 mg dose, you took 40 mg, which is the FDA-approved maximum. Doctors prescribe this amount every day.
If you doubled a 40 mg dose, you took 80 mg. This is above the approved maximum, but it was studied in clinical trials with no dose-related trends in adverse events. Still, contact your doctor or pharmacist to let them know.
What happens after a double dose of olmesartan
Olmesartan has a half-life of about 13 hours. The extra dose will take longer to clear compared to shorter-acting ARBs like losartan (half-life of about 6 to 9 hours for the active metabolite). Blood levels will peak 1 to 2 hours after taking the pill, then gradually decline.
Here is a rough timeline:
- 1 to 2 hours after the double dose: Blood levels peak. This is when you are most likely to notice blood pressure effects.
- 6 to 8 hours: Blood levels are declining but still elevated above your normal dose.
- 13 hours (one half-life): The extra amount has dropped by half.
- 24 to 26 hours: Most of the excess dose has cleared. Your body is returning to its normal baseline.
During this window, the main concern is low blood pressure (hypotension). According to the FDA label, the most likely symptoms of an olmesartan overdose are hypotension (low blood pressure), tachycardia (fast heart rate), or bradycardia (slow heart rate).
What to do right now
- Stay calm. A single double dose at typical prescribed levels is unlikely to cause a medical emergency.
- Check your blood pressure if you have a home monitor. Systolic (top number) below 90 mmHg with symptoms like dizziness means you should call your doctor.
- Sit or lie down. This reduces the chance of falling if your blood pressure drops.
- Stay hydrated. Drink water throughout the day. Dehydration makes low blood pressure worse.
- Avoid standing up quickly. Rise slowly from sitting or lying positions.
- Avoid alcohol. Both alcohol and olmesartan lower blood pressure. Together, the effect is stronger.
- Consider skipping your next scheduled dose. If you doubled a 40 mg dose, this is generally recommended. If you doubled a 20 mg dose (to 40 mg, the approved max), check with your pharmacist about whether to skip. Resume your regular schedule after that. Do not take extra doses to "catch up."
- Write down the time and amount you took. This helps if you need to call your doctor or pharmacist later.
Symptoms to watch for
Mild symptoms (usually pass on their own)
These may be more noticeable after a double dose:
- Dizziness or lightheadedness
- Feeling tired or weak
- Mild headache
These typically resolve as the extra drug clears your system. Given olmesartan's 13-hour half-life, most of the excess should clear within 24 to 26 hours.
Serious symptoms (call your doctor)
Contact your doctor or pharmacist if you experience:
- Significant dizziness or near-fainting that does not improve with lying down
- Heart palpitations or fast heartbeat that persists
- Very low blood pressure (systolic below 90 mmHg) with symptoms
- Decreased urination or signs of kidney changes
Emergency symptoms (call 911)
Seek immediate help for any of these:
- Fainting or loss of consciousness
- Chest pain or severe shortness of breath
- Severe dizziness that does not improve after lying down
These would be very unusual from a single double dose at typical prescribed levels, but they require immediate attention.
When to call your doctor or Poison Control
For most people on 20 mg, a single accidental double dose does not need emergency care. Contact a professional if:
- You took more than one extra dose (three or more pills instead of one)
- You doubled a 40 mg dose (80 mg total, above the approved maximum)
- You take other blood pressure medications that could stack with olmesartan's effect
- You take potassium supplements or potassium-sparing diuretics. Olmesartan can raise potassium levels by blocking angiotensin II. A double dose could temporarily increase this effect.
- You have kidney disease. In severe kidney impairment, olmesartan blood levels can triple, so a double dose hits harder.
- You are dehydrated. Low fluid volume amplifies the blood pressure drop.
- You are pregnant or may be pregnant. Olmesartan carries an FDA black box warning: it can cause injury or death to a developing fetus. If you are pregnant and took a double dose, contact your doctor right away.
- You notice any serious or emergency symptoms listed above
Contact numbers:
- Poison Control: 1-800-222-1222 (free, 24/7)
- Your pharmacist: Quick, accessible guidance based on your specific medication profile
- 911: For emergencies
How olmesartan compares to other ARBs in a double-dose scenario
If you have taken other blood pressure medications before, you might wonder how olmesartan stacks up. Compared to losartan, olmesartan has a longer half-life (13 hours vs. 6 to 9 hours for losartan's active metabolite). The effects of a double dose last longer. However, olmesartan also has a wider studied dose range (up to 80 mg in clinical trials, linear pharmacokinetics up to 320 mg), which provides a larger safety cushion.
For a broader overview of doubling blood pressure medications, see our guide on accidentally taking a double dose of blood pressure medication.
How to prevent accidental double dosing
The most common scenario: you take your olmesartan, get busy with your morning, and 30 minutes later you cannot remember if you actually took it. About 300,000 medication errors are reported to poison control centers yearly in the US, and most happen at home. A few approaches that help:
Track every dose with a medication reminder app
Regular phone alarms tell you when to take a pill, but they do not record whether you actually did. A dedicated tracking app logs every confirmed dose, so you always have a clear answer to "did I already take this?"
Pillo tracks every dose you confirm and uses persistent alarms that won't stop until you respond. If you manage olmesartan alongside other medications, that kind of tracking prevents exactly this kind of mix-up.
Use a weekly pill organizer
A 7-day organizer gives you instant visual confirmation. Compartment empty? You took it. Compartment full? Take it now.
Take olmesartan at the same time every day
Consistency reduces confusion. Building it into an existing routine (like breakfast or brushing your teeth) makes it automatic. For more strategies, see our medication routine guide.
Frequently asked questions
Is a double dose of olmesartan dangerous?
For most people on standard doses (20 or 40 mg), a single accidental double dose is not dangerous. If you doubled 20 mg to 40 mg, you are at the FDA-approved maximum. If you doubled 40 mg to 80 mg, a pooled analysis of clinical trials showed this dose had a tolerability profile similar to placebo. The main risk is a temporary drop in blood pressure causing dizziness. Contact your doctor if you experience persistent symptoms.
Should I skip my next dose of olmesartan after doubling?
Yes. Skip your next scheduled dose, then resume your regular schedule. Do not stop taking olmesartan entirely. Sudden discontinuation of blood pressure medication can cause rebound blood pressure increases. If you are unsure about timing, check with your pharmacist.
How long until the extra olmesartan wears off?
Olmesartan has a half-life of about 13 hours. Most of the extra dose's effects should resolve within 24 to 26 hours. Stay hydrated and avoid standing up quickly during that window.
What if I am not sure whether I already took my olmesartan?
If you genuinely cannot remember, it is safer to skip that dose than to risk doubling up. One missed dose of olmesartan is unlikely to cause problems, while a double dose can cause a noticeable blood pressure drop. For more on this situation, see our guide on what to do when you can't remember if you took your medication.
Is olmesartan the same as losartan?
No, but they are in the same drug class (ARBs). Both lower blood pressure by blocking angiotensin II receptors. Olmesartan tends to produce greater blood pressure reduction at starting doses and has a longer half-life (13 hours vs. 6 to 9 hours for losartan's active metabolite). If you doubled losartan instead, see our guide on accidentally doubling losartan.
Related guides
- Accidentally doubled your blood pressure medication
- Accidentally took double dose of losartan
- Can't remember if you took your medication?
- Medications you should never skip
Medical Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your doctor or pharmacist for advice specific to your medications. If you think you may have a medical emergency, call 911 or your local emergency number immediately.
Reviewed sources: FDA Benicar Label (DailyMed), StatPearls - Olmesartan, MedlinePlus - Olmesartan, Poison Control
