OLMESARTAN MEDOXOMIL

Clinical safety rating: avoid

NSAIDs may diminish the antihypertensive effect Lithium levels may be increased Use in pregnancy can cause injury and death to the developing fetus.

How it works

Olmesartan medoxomil is a prodrug that is hydrolyzed to olmesartan, a selective angiotensin II receptor type 1 (AT1) antagonist. It blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II, leading to decreased peripheral vascular resistance and reduced blood pressure.

What the body does with it

Metabolism	Olmesartan medoxomil is completely hydrolyzed to olmesartan during absorption by esterases in the gastrointestinal tract. Olmesartan is not metabolized by the cytochrome P450 system and is excreted unchanged in the urine (35-50%) and feces (50-65%).
Excretion	Renal: 35-50% as unchanged drug; biliary/fecal: 50-65% via bile into feces, primarily as parent drug.
Half-life	Terminal elimination half-life: 10-15 hours; reaches steady-state after 3-5 days; clinically allows once-daily dosing.
Protein binding	>99% bound, primarily to albumin and alpha-1-acid glycoprotein.
Volume of Distribution	Vd: 17-24 L/kg; indicates extensive tissue distribution.
Bioavailability	Oral: 26% (absolute bioavailability due to extensive first-pass metabolism).
Onset of Action	Oral: 1-2 hours for peak plasma concentration; antihypertensive effect begins within 1 week, maximal at 2-4 weeks.
Duration of Action	24 hours with once-daily dosing; blood pressure reduction sustained over 24-hour dosing interval.

Classification & Brands

Dosing & administration

20 mg orally once daily, titrate as needed to 40 mg once daily; maximum 40 mg daily.

Dosage form	TABLET
Renal impairment	No adjustment required for GFR ≥20 mL/min; contraindicated if GFR <20 mL/min.
Liver impairment	No dosage adjustment necessary for mild-to-moderate hepatic impairment (Child-Pugh A or B); not recommended in severe hepatic impairment (Child-Pugh C) due to lack of data.
Pediatric use	Children 1-16 years: initial dose 0.1 mg/kg (max 20 mg) orally once daily, titrate up to 0.6 mg/kg (max 40 mg) once daily; weigh-based titration.
Geriatric use	Initiate at 10 mg once daily in elderly patients ≥75 years due to increased risk of hypotension; titrate slowly.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

NSAIDs may diminish the antihypertensive effect Lithium levels may be increased Use in pregnancy can cause injury and death to the developing fetus.

FDA category	Contraindicated
Breastfeeding	No human data; M/P ratio unknown. Olmesartan is excreted in rat milk. Consider risks to infant (renal effects) and benefits of breastfeeding; alternative preferred if breastfeeding.
Teratogenic Risk	First trimester: Limited data; potential risk based on mechanism (RAAS inhibition). Second and third trimesters: Fetal toxicity including oligohydramnios, renal dysplasia, skull ossification defects, hypotension, and anuria. Avoid in second and third trimesters; use alternative if possible in first trimester.

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Common Effects	Sleepiness Taste change Ankle swelling Headache Flushing sense of warmth in the face ears neck and trunk Dizziness Tiredness Palpitations Upset stomach Increased potassium level in blood
Serious Effects

Absolute Contraindications

["Hypersensitivity to olmesartan or any component","Pregnancy (2nd and 3rd trimesters)","Coadministration with aliskiren in patients with diabetes mellitus"]

Clinical Precautions

Precautions

["Hypotension in volume-depleted patients","Worsening renal function, especially in patients with renal artery stenosis","Hyperkalemia, particularly in patients with renal impairment or on potassium-sparing diuretics","Fetal toxicity: potential for oligohydramnios and fetal renal dysfunction if used during pregnancy"]

Clinical Tips & Counseling

Drug interactions

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OLMESARTAN MEDOXOMIL

Clinical safety rating: avoid

NSAIDs may diminish the antihypertensive effect Lithium levels may be increased Use in pregnancy can cause injury and death to the developing fetus.

How it works

What the body does with it

Metabolism	Olmesartan medoxomil is completely hydrolyzed to olmesartan during absorption by esterases in the gastrointestinal tract. Olmesartan is not metabolized by the cytochrome P450 system and is excreted unchanged in the urine (35-50%) and feces (50-65%).
Excretion	Renal: 35-50% as unchanged drug; biliary/fecal: 50-65% via bile into feces, primarily as parent drug.
Half-life	Terminal elimination half-life: 10-15 hours; reaches steady-state after 3-5 days; clinically allows once-daily dosing.
Protein binding	>99% bound, primarily to albumin and alpha-1-acid glycoprotein.
Volume of Distribution	Vd: 17-24 L/kg; indicates extensive tissue distribution.
Bioavailability	Oral: 26% (absolute bioavailability due to extensive first-pass metabolism).
Onset of Action	Oral: 1-2 hours for peak plasma concentration; antihypertensive effect begins within 1 week, maximal at 2-4 weeks.
Duration of Action	24 hours with once-daily dosing; blood pressure reduction sustained over 24-hour dosing interval.

Classification & Brands

Dosing & administration

20 mg orally once daily, titrate as needed to 40 mg once daily; maximum 40 mg daily.

Dosage form	TABLET
Renal impairment	No adjustment required for GFR ≥20 mL/min; contraindicated if GFR <20 mL/min.
Liver impairment	No dosage adjustment necessary for mild-to-moderate hepatic impairment (Child-Pugh A or B); not recommended in severe hepatic impairment (Child-Pugh C) due to lack of data.
Pediatric use	Children 1-16 years: initial dose 0.1 mg/kg (max 20 mg) orally once daily, titrate up to 0.6 mg/kg (max 40 mg) once daily; weigh-based titration.
Geriatric use	Initiate at 10 mg once daily in elderly patients ≥75 years due to increased risk of hypotension; titrate slowly.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

NSAIDs may diminish the antihypertensive effect Lithium levels may be increased Use in pregnancy can cause injury and death to the developing fetus.

FDA category	Contraindicated
Breastfeeding	No human data; M/P ratio unknown. Olmesartan is excreted in rat milk. Consider risks to infant (renal effects) and benefits of breastfeeding; alternative preferred if breastfeeding.
Teratogenic Risk	First trimester: Limited data; potential risk based on mechanism (RAAS inhibition). Second and third trimesters: Fetal toxicity including oligohydramnios, renal dysplasia, skull ossification defects, hypotension, and anuria. Avoid in second and third trimesters; use alternative if possible in first trimester.

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Common Effects	Sleepiness Taste change Ankle swelling Headache Flushing sense of warmth in the face ears neck and trunk Dizziness Tiredness Palpitations Upset stomach Increased potassium level in blood
Serious Effects

Absolute Contraindications

["Hypersensitivity to olmesartan or any component","Pregnancy (2nd and 3rd trimesters)","Coadministration with aliskiren in patients with diabetes mellitus"]