What type of medication is olmesartan?

Olmesartan is an Angiotensin II Receptor Blocker (ARB)

Olmesartan medoxomil is an angiotensin II type 1 (AT1) receptor antagonist (angiotensin receptor blocker or ARB) used primarily for the treatment of hypertension. 1

Pharmacology and Mechanism of Action

• Olmesartan medoxomil is a prodrug that is hydrolyzed to olmesartan (the active metabolite) during absorption from the gastrointestinal tract 1
• It works by selectively blocking the binding of angiotensin II to the AT1 receptors, thereby inhibiting the vasoconstrictor and aldosterone-secreting effects of angiotensin II 1, 2
• Olmesartan has a high affinity for the AT1 receptor and acts as a competitive and insurmountable angiotensin II antagonist 3
• It has linear pharmacokinetics without cytochrome P450 interaction, reducing the potential for drug interactions 3

Clinical Uses

• FDA-approved for the treatment of hypertension in adults and children six years of age and older 1
• Can be used as monotherapy or in combination with other antihypertensive agents 1
• Lowering blood pressure with olmesartan reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions 1
• Often used in patients who cannot tolerate ACE inhibitors due to cough or angioedema 4

Dosing Information

• Usual dose range for olmesartan is 20-40 mg once daily 4
• Initial starting dose is typically 20 mg once daily, which can be increased to 40 mg if needed 2
• Olmesartan demonstrates dose-dependent blood pressure-lowering effects between 10 and 80 mg 3
• Available as film-coated tablets containing 5 mg, 20 mg, or 40 mg of olmesartan medoxomil 1

Efficacy

• Olmesartan has demonstrated rapid blood pressure-lowering effects, typically within 1 week of treatment initiation 3
• In head-to-head trials, olmesartan has shown either similar or superior efficacy compared to other ARBs (losartan, valsartan, irbesartan, and candesartan) at their recommended maintenance doses 5
• Provides consistent antihypertensive efficacy throughout the 24-hour dosage interval, including during the last 4 hours of this period 6
• May also reduce vascular microinflammation, decrease intrarenal vascular resistance, and exert antiatherosclerotic effects 3

Combination Therapy

• When blood pressure control is inadequate with monotherapy, olmesartan can be combined with hydrochlorothiazide in fixed-dose combinations 6
• Olmesartan-based combination therapies have shown good efficacy and tolerability profiles with high adherence in fixed single-pill formulations 7
• Available fixed-dose combinations include olmesartan-hydrochlorothiazide (20/12.5 mg, 40/12.5 mg, 40/25 mg) 4

Safety and Adverse Effects

• Generally well-tolerated with an adverse event profile similar to placebo 3
• Common with other ARBs, olmesartan may cause hyperkalemia, especially in patients with chronic kidney disease or those on potassium supplements 4
• Risk of acute renal failure in patients with severe bilateral renal artery stenosis 4
• Contraindicated during pregnancy due to potential fetal harm 4
• Should not be used in combination with ACE inhibitors or direct renin inhibitors due to increased risk of adverse effects 4

Special Considerations

• Combining olmesartan with ACE inhibitors and beta-blockers is not recommended (Class III recommendation) 4
• In heart failure patients with preserved ejection fraction (HFpEF), olmesartan should not be combined with ACE inhibitors and beta-blockers 4
• Monitoring of renal function is essential with olmesartan, as with ACE inhibitors 4

Olmesartan represents a valuable treatment option for hypertension management due to its consistent antihypertensive efficacy and favorable tolerability profile when used as monotherapy or in combination therapy.