Olmesartan Drug Profile

What is Olmesartan?

Olmesartan is an oral medication belonging to a class of drugs called angiotensin receptor blockers (ARBs). It is primarily prescribed to treat high blood pressure (hypertension) by blocking certain receptors that cause blood vessels to constrict. This medication helps lower blood pressure and reduce the risk of cardiovascular complications associated with hypertension.

Uses

• Hypertension (High Blood Pressure): The primary FDA-approved use for treating elevated blood pressure in adults and children 6 years and older
• Cardiovascular Protection: Helps reduce the risk of heart attack, stroke, and other cardiovascular events in patients with hypertension
• Kidney Protection in Diabetics: May help protect kidney function in patients with diabetes and high blood pressure
• Heart Failure Management: Sometimes used as part of combination therapy for certain patients with heart failure when ACE inhibitors are not tolerated
• Combination Therapy: Often prescribed alongside other blood pressure medications like diuretics or calcium channel blockers for enhanced blood pressure control

How it works

Olmesartan works by blocking angiotensin II receptors in blood vessels, preventing this hormone from binding and causing blood vessel constriction. When these receptors are blocked, blood vessels remain relaxed and widened, allowing blood to flow more easily and reducing the pressure against vessel walls. This mechanism effectively lowers blood pressure and reduces the workload on the heart.

Side effects

Common side effects:

• Dizziness or lightheadedness
• Headache
• Fatigue or weakness
• Nausea
• Upper respiratory tract infections
• Back pain
• Diarrhea
• Bronchitis

Serious side effects requiring immediate medical attention:

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• Severe diarrhea with substantial weight loss (sprue-like enteropathy)
• Signs of kidney problems (changes in urination, swelling)
• Hyperkalemia (high potassium levels causing irregular heartbeat)
• Severe allergic reactions (swelling of face, lips, tongue, or throat)
• Severe hypotension (extremely low blood pressure causing fainting)

Warnings and precautions

• Pregnancy: Olmesartan can cause serious harm to developing babies and should not be used during pregnancy, particularly in the second and third trimesters
• Kidney Function: Patients with kidney disease or those taking medications affecting kidney function require careful monitoring and possible dose adjustments
• Dehydration Risk: Patients who are dehydrated or taking diuretics may experience excessive blood pressure lowering when starting olmesartan
• Sprue-like Enteropathy: A rare but serious intestinal condition has been reported, causing chronic diarrhea and weight loss that may develop months to years after starting treatment
• Liver Impairment: Patients with liver problems may need dose adjustments and closer monitoring

Interactions

• ACE Inhibitors: Combining with ACE inhibitors increases the risk of kidney problems and dangerously low blood pressure
• Potassium Supplements and Salt Substitutes: May lead to dangerous elevations in blood potassium levels
• Diuretics: Can enhance blood pressure lowering effects, potentially causing excessive hypotension
• Lithium: Olmesartan may increase lithium blood levels, potentially leading to lithium toxicity
• NSAIDs (Ibuprofen, Naproxen): May reduce the blood pressure lowering effects and increase kidney damage risk
• Potassium-Sparing Diuretics: Increases risk of hyperkalemia when combined with spironolactone or amiloride
• Aliskiren: Should not be combined with olmesartan in patients with diabetes or kidney impairment due to increased risk of complications
• Colesevelam: This cholesterol medication can reduce olmesartan absorption if taken at the same time

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Dosage

For adults with hypertension, the typical starting dose is 20 mg once daily, which may be increased to 40 mg once daily if additional blood pressure reduction is needed. The maximum recommended dose is 40 mg daily. For elderly patients or those with kidney impairment, a lower starting dose of 5-10 mg daily may be appropriate. Olmesartan can be taken with or without food, and should be taken at the same time each day for optimal effectiveness. Dosage should always be individualized and determined by a healthcare provider based on the patient’s specific condition, response to treatment, and other factors.

Sources: FDA DailyMed drug labels (public domain), BNF, WHO Essential Medicines List. This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting or stopping any medication.

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