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Olmesartan Medoxomil


Pronunciation: OL-me-SAR-tan me-DOX-oh-mil
Class: Angiotensin II receptor antagonist

Trade Names

- Tablets, oral 5 mg
- Tablets, oral 20 mg
- Tablets, oral 40 mg


Blocks vasoconstrictor effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT 1 receptor in vascular smooth muscle.

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Rapidly and completely bioactivated by ester hydrolysis to olmesartan during absorption from the GI tract. Steady state is within 3 to 5 d. Bioavailability is approximately 26%. T max is 1 to 2 h.


Vd is 17 L. 99% is protein bound.


Approximately 35% to 50% is eliminated through urine; the remainder is eliminated in feces via bile. Total plasma Cl is 1.3 L/h. Renal Cl is 0.6 L/h. Elimination half-life is approximately 13 h.

Special Populations

Renal Function Impairment

AUC is approximately tripled when CrCl is less than 20 mL/min.

Hepatic Function Impairment

In patients with moderate hepatic impairment, AUC increased by approximately 60%; C max was also increased.


AUC increased by 33%, and there is a 30% reduction in renal Cl.


Cl was similar to adults when adjusted by body weight.


AUC and C max increased 10% to 15% in women.


Antihypertensive effect was smaller in black patients.

Indications and Usage

Treatment of hypertension.

Unlabeled Uses

Prevention of migraine.


None well documented.

Dosage and Administration


PO Start with 20 mg once daily when used as monotherapy in patients who are not volume contracted; after 2 wk, dosage may be increased to 40 mg/day.

Children (6 to 16 y of age)

PO Start with 10 mg once daily for patients who weigh 20 to less than 35 kg, or 20 mg once daily for patients who weigh 35 kg or more. After 2 wk, dosage may be increased to a max of 20 mg/day for patients who weigh 20 to less than 35 kg, or 40 mg/day for patients who weigh 35 kg or more.

General Advice

  • If BP is not controlled by olmesartan alone, a diuretic or other antihypertensive agent may be added.
  • For patients with depletion of intravascular volume, consider using a lower starting dose.
  • May be administered with or without food.
  • For children who cannot swallow tablets, the same dose can be given using an extemporaneous suspension. See manufacturer's prescribing information for directions.


Store at 68° to 77°F. The extemporaneously prepared suspension should be refrigerated at 36° to 46°F and can be stored for up to 4 wk.

Drug Interactions

ACE inhibitors (eg, captopril)

Coadministration may be associated with an increased risk of renal dysfunction and hyperkalemia. Consider monotherapy. If coadministration cannot be avoided, closely monitor renal function and serum potassium.


The risk of hyperkalemia may be increased, particularly in diabetic patients. Coadministration is not recommended in diabetic patients. If coadministration cannot be avoided, closely monitor potassium concentrations and renal function.

COX-2 inhibitors (eg, celecoxib), NSAIDs (eg, ibuprofen)

The antihypertensive effect of olmesartan may be decreased. Coadministration of NSAIDs with olmesartan in patients who are elderly or volume-depleted (including those on diuretic therapy), or have compromised renal function, may result in deterioration of renal function, including possible acute renal failure. Monitor BP and renal function periodically.


Increased lithium concentrations and toxicity may occur during coadministration. Monitor lithium and serum concentrations, and observe the clinical response of the patient. Adjust the lithium dose as needed.

Potassium preparations (eg, potassium supplements, salt substitutes containing potassium, potassium-sparing diuretics [eg, spironolactone])

The risk of hyperkalemia, possibly with cardiac arrhythmias or arrest, is increased. Closely monitor serum potassium concentrations and renal function. Adjust therapy as needed.


The risk of hyperkalemia may be increased, especially in elderly patients. An alternative antibiotic may be preferred in elderly patients. If coadministration cannot be avoided, closely monitor potassium concentrations and the clinical response.

Adverse Reactions


Dizziness (3%); headache, vertigo (more than 1%); asthenia (postmarketing).


Rash (more than 1%); alopecia, pruritus, urticaria (postmarketing).


Abdominal pain, diarrhea, dyspepsia, gastroenteritis, nausea (more than 1%); vomiting (postmarketing).


Hematuria (more than 1%); acute renal failure, increased blood creatinine levels (postmarketing).


Anaphylactic reactions, angioedema (postmarketing).


Hypercholesterolemia, hyperglycemia, hyperlipemia, hypertriglyceridemia, hyperuricemia (more than 1%); hyperkalemia (postmarketing).


Arthralgia, arthritis, back pain, myalgia (more than 1%); rhabdomyolysis (postmarketing).


Bronchitis, pharyngitis, rhinitis, sinusitis (more than 1%); cough (1%).


Chest pain, CPK increased, influenza-like symptoms, peripheral edema, tachycardia (more than 1%); facial edema.



When pregnancy is detected, discontinue olmesartan as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and even death to the developing fetus.


Assess renal function, BP, and volume status during initiation of therapy, dose escalation, and periodically thereafter.


Category D . Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hyperplasia, anuria, hypotension, renal failure, and death.




Effectiveness for hypertension has not been shown for children younger than 6 y. Infants younger than 1 y must not receive olmesartan for hypertension.


Use with caution.

Renal Function

In patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or BUN may occur.


Symptomatic hypotension may be anticipated after initiation of treatment in patients with an activated renin-angiotensin system, such as volume- and/or salt-depleted patients.

Renal effects

In patients whose renal function may depend on activity of the renin-angiotensin-aldosterone system (eg, patients with severe CHF), treatment may be associated with oliguria and/or progressive azotemia, rarely resulting in acute renal failure and/or death.



Bradycardia, hypotension, tachycardia.

Patient Information

  • Advise women of childbearing age about the consequences of olmesartan during pregnancy. Discuss treatment options with women planning to become pregnant. Instruct these patients to report pregnancies to their health care provider as soon as possible.
  • Caution patient that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to an excessive fall in BP, resulting in light-headedness or fainting.
  • Advise patients not to take potassium supplements or salt substitutes containing potassium without consulting their health care provider.

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