Olmesartan

Oral
Hypertension
Adult: As olmesartan medoxomil: Initially, 10-20 mg once daily, may be increased to 40 mg once daily if necessary.
Child: ≥6 years Same as adult dose. Max: <35 kg: 20 mg daily; ≥35 kg: 40 mg daily.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<20	Not recommended.
20-60	Max: 20 mg once daily.

Hepatic impairment: Moderate: Initially, 10 mg once daily. Max: 20 mg once daily. Severe: Not recommended.

Biliary obstruction. Pregnancy. Concomitant use with aliskiren-containing products in patients with diabetes mellitus or renal impairment (GFR <60 mL/min/1.73 m²).

Patient with volume or salt depletion, unstented unilateral or bilateral renal artery stenosis, diabetes mellitus, significant aortic or mitral valve stenosis, obstructive hypertrophic cardiomyopathy, ascites due to cirrhosis or refractory ascites, primary aldosteronism, history of angioedema. Patient undergoing surgery. Black patients. Renal and hepatic impairment. Children and elderly. Lactation. Patient Counselling This drug may cause dizziness or fatigue, if affected, do not drive or operate machinery. Monitoring Parameters Monitor blood pressure, electrolytes (e.g. serum K levels), renal function, and urinalysis. Assess for signs of angioedema.

Significant: Symptomatic hypotension (particularly in patients with salt or volume depletion), hyperkalaemia, sprue-like enteropathy (characterised as severe, chronic diarrhoea with significant weight loss); renal function deterioration and/or increased serum creatinine. Rarely, angioedema. Cardiac disorders: Chest pain. Gastrointestinal disorders: Gastroenteritis, diarrhoea, nausea, dyspepsia, abdominal pain. General disorders and administration site conditions: Pain, peripheral oedema, facial oedema, influenza-like symptoms, fatigue. Investigations: Increased hepatic enzymes, BUN, creatine phosphokinase. Metabolism and nutrition disorders: Hypertriglyceridaemia, hyperuricaemia. Musculoskeletal and connective tissue disorders: Arthritis, skeletal pain, back pain. Nervous system disorders: Headache, dizziness. Renal and urinary disorders: UTI, haematuria. Respiratory, thoracic and mediastinal disorders: Bronchitis, cough, rhinitis, pharyngitis.

Symptoms: Hypotension, tachycardia, bradycardia. Management: Symptomatic and supportive treatment.

Enhanced hypotensive effect with other antihypertensive agents. May increase serum K level with K-sparing diuretics, K supplements, K-containing salt substitutes, or other drugs that may elevate serum K levels (e.g. heparin, trimethoprim). May increase the serum concentrations and toxicity of lithium. Decreased glomerular filtration and renal function with NSAIDs (including selective COX-2 inhibitors). Reduced systemic exposure and peak plasma concentration with colesevelam; administer olmesartan at least 4 hours prior to colesevelam.
Potentially Fatal: Increased risk of hypotension, hyperkalaemia, and reduced renal function (including acute renal failure) with aliskiren and ACE inhibitors.

Olmesartan is a competitive and selective angiotensin II receptor antagonist. It blocks all the actions of angiotensin II mediated by the (AT₁) receptors, resulting in increased in plasma renin levels and angiotensin I and II concentrations, and some decreased in plasma aldosterone concentrations.
Absorption: Bioavailability: Approx 26%. Time to peak plasma concentration: 1-2 hours.
Distribution: Volume of distribution: Approx 17 L. Plasma protein binding: Approx 99%.
Metabolism: Olmesartan medoxomil undergoes ester hydrolysis in the gastrointestinal tract to active form olmesartan.
Excretion: Via faeces (50-65%) and urine (35-50%) as unchanged drug. Terminal elimination half-life: Approx 10-15 hours.

Oral: Store between 20-25°C.

Angiotensin II Antagonists