1. Introduction
Olmesartan is an angiotensin II receptor blocker (ARB) used primarily to treat hypertension (high blood pressure). It works by blocking the action of angiotensin II, a hormone that causes blood vessels to constrict. This leads to relaxation of the blood vessels, lowering blood pressure, and reducing the risk of cardiovascular complications such as stroke and heart attack.
2. Indications
- Treatment of hypertension (high blood pressure)
- Reduction of cardiovascular risk in patients with hypertension
- Off-label: Proteinuria and diabetic nephropathy
3. Dosage
Adults:
- Hypertension:
- Starting dose: 20 mg once daily.
- Maintenance dose: 20–40 mg once daily.
- Maximum dose: 40 mg/day.
Children (≥6 years):
- Starting dose: 10 mg once daily (for body weight <35 kg).
- Increase to 20 mg once daily (for body weight ≥35 kg).
Elderly:
- Start at the lower end of the dosing range due to the potential for reduced renal function.
4. Administration
- Take orally once daily, with or without food.
- Administer at the same time each day to maintain consistent blood pressure control.
- Do not chew or crush tablets; swallow whole with water.
5. Forms Available
- Tablets: 5 mg, 20 mg, 40 mg
6. Side Effects
6.1 Common Side Effects:
- Dizziness
- Fatigue
- Headache
- Nausea
6.2 Less Common Side Effects:
- Diarrhoea
- Back pain
- Bronchitis
6.3 Rare but Serious Side Effects:
- Severe hypotension (especially in volume-depleted patients)
- Hyperkalaemia (elevated potassium levels)
- Renal impairment
- Sprue-like enteropathy (severe, chronic diarrhoea with weight loss)
7. Warnings
- Hypotension: Risk of severe hypotension in patients who are volume- or salt-depleted. Correct the volume/salt imbalance before initiating treatment.
- Renal Impairment: Monitor renal function regularly, especially in patients with pre-existing kidney conditions.
- Sprue-like Enteropathy: Rare cases of severe diarrhoea and weight loss have been reported; discontinue if symptoms occur.
8. Precautions
- Use cautiously in patients with severe renal or hepatic impairment.
- Monitor potassium levels, especially when used with potassium supplements, potassium-sparing diuretics, or other drugs that increase potassium levels.
- Avoid in patients with bilateral renal artery stenosis, as this may worsen renal function.
9. Interactions
- Potassium-sparing diuretics (e.g., spironolactone): Increased risk of hyperkalaemia.
- NSAIDs (e.g., ibuprofen): May reduce antihypertensive effects and worsen renal function.
- Lithium: Increased lithium levels and risk of toxicity.
- ACE inhibitors or other ARBs: Increased risk of hyperkalaemia, hypotension, and renal dysfunction; avoid concurrent use.
10. Monitoring Parameters
- Blood pressure (to ensure effective control).
- Renal function tests (e.g., serum creatinine, BUN) before and during therapy.
- Potassium levels periodically to detect hyperkalaemia.
11. Use in Children
- Approved for use in children ≥6 years of age for hypertension. Dose adjustments are based on body weight.
12. Use in Pregnancy
- Contraindicated in pregnancy (Category D). Can cause foetal harm, including renal dysfunction, hypotension, and death. Discontinue immediately if pregnancy is detected.
13. Use in Elderly
- Initiate treatment cautiously due to the increased likelihood of renal dysfunction and sensitivity to hypotension.
14. Use in Kidney Disease
- Use cautiously in patients with renal impairment. Monitor renal function regularly, especially in patients with a baseline estimated glomerular filtration rate (eGFR) <60 mL/min.
15. Use in Liver Disease
- Use cautiously in patients with moderate hepatic impairment. Dose adjustments may not be required, but monitoring is advised.
16. Patient Counselling Points
- Take Olmesartan at the same time each day, with or without food.
- Do not stop taking Olmesartan without consulting your doctor, as it may worsen blood pressure control.
- Report any persistent diarrhoea, severe dizziness, or swelling of the face, lips, or throat immediately.
- Avoid potassium supplements or potassium-rich foods (e.g., bananas, oranges) unless directed by your doctor.
- Inform your doctor if you become pregnant while taking Olmesartan.
17. Table of Brand Names, Manufacturer, and Prices in USD
Brand Name | Manufacturer | Strength/Dosage Form | Price (USD) |
---|---|---|---|
Benicar | Daiichi Sankyo | 20 mg Tablet | $50 (30 tablets) |
Olmetec | Daiichi Sankyo | 40 mg Tablet | $60 (30 tablets) |
Generic Olmesartan | Various | 20 mg Tablet | $20 (30 tablets) |
18. 15 FAQs (Frequently Asked Questions)
1. What is Olmesartan used for?
Olmesartan is used to treat high blood pressure and reduce cardiovascular risks associated with hypertension.
2. How does Olmesartan work?
It blocks angiotensin II receptors, causing blood vessels to relax and lowering blood pressure.
3. Can Olmesartan cause diarrhoea?
Yes, rare cases of severe, chronic diarrhoea (sprue-like enteropathy) have been reported.
4. What is the usual dose of Olmesartan?
The usual dose is 20–40 mg once daily for hypertension.
5. Can Olmesartan be taken during pregnancy?
No, it is contraindicated during pregnancy due to the risk of foetal harm.
6. Can children take Olmesartan?
Yes, it is approved for children aged ≥6 years for hypertension.
7. Does Olmesartan cause weight gain?
No, weight gain is not a common side effect of Olmesartan.
8. How long does Olmesartan take to work?
Blood pressure reduction is typically seen within 1–2 weeks, with maximum effects in 4–6 weeks.
9. Can Olmesartan be taken with NSAIDs?
NSAIDs may reduce its efficacy and worsen kidney function; avoid prolonged use without monitoring.
10. Does Olmesartan cause drowsiness?
No, drowsiness is not a common side effect of Olmesartan.
11. Can I take Olmesartan with other blood pressure medications?
Yes, but avoid combining it with other ARBs or ACE inhibitors due to an increased risk of hyperkalaemia and renal dysfunction.
12. Can Olmesartan be stopped abruptly?
No, stopping suddenly may lead to a rebound increase in blood pressure. Consult your doctor before stopping.
13. How should Olmesartan be stored?
Store at room temperature, away from moisture and heat.
14. Can Olmesartan cause kidney problems?
Yes, it may worsen renal function in some patients. Regular monitoring is essential.
15. Do I need a prescription for Olmesartan?
Yes, Olmesartan is a prescription-only medication.