Valsartan – Uses, Dosage and Side Effects

What is Valsartan?

Valsartan is a prescription medication belonging to the class of angiotensin II receptor blockers (ARBs), also known as sartans. It is primarily used to treat high blood pressure (hypertension), heart failure, and to improve outcomes following a heart attack (myocardial infarction). Valsartan has been approved since the 1990s and is one of the most widely prescribed blood pressure medications worldwide.

Mechanism of Action

Valsartan selectively blocks the angiotensin II type 1 receptor (AT1 receptor). Angiotensin II is a naturally occurring hormone that causes strong narrowing of the blood vessels and raises blood pressure. By blocking this receptor, valsartan prevents the vasoconstrictive effects of angiotensin II. This leads to widening of the blood vessels (vasodilation), a reduction in blood pressure, and a reduction in the workload of the heart.

Unlike ACE inhibitors, a related drug class, valsartan blocks the receptor directly rather than inhibiting the formation of angiotensin II. As a result, the dry cough commonly associated with ACE inhibitors occurs far less frequently with valsartan.

Indications

• Arterial hypertension (high blood pressure) in adults and children aged 6 years and older
• Heart failure, particularly when ACE inhibitors are not tolerated
• Post-myocardial infarction: to improve cardiac function and reduce the risk of further cardiovascular events

Dosage

The dosage of valsartan depends on the condition being treated and is always determined individually by the treating physician.

• High blood pressure: Typically 80 mg to 160 mg once daily, with possible increases up to 320 mg daily
• Heart failure: Starting dose usually 40 mg twice daily, gradually increased up to 160 mg twice daily
• Post-myocardial infarction: Starting dose 20 mg twice daily, target dose up to 160 mg twice daily

Valsartan can be taken with or without food and is available in tablet form. The blood pressure-lowering effect typically begins within 2 hours, with the maximum effect reached after 4 to 6 hours.

Side Effects

Valsartan is generally well tolerated. Possible side effects include:

• Common: Dizziness, headache, fatigue
• Occasional: Hypotension (low blood pressure), hyperkalemia (elevated potassium levels in the blood), impaired kidney function
• Rare: Angioedema (swelling beneath the skin, particularly affecting the face and throat), elevated liver enzymes

Unlike ACE inhibitors, valsartan does not cause or very rarely causes a dry irritating cough, as it does not inhibit the ACE enzyme and therefore does not lead to bradykinin accumulation.

Contraindications and Interactions

Valsartan must not be taken in cases of:

• Known hypersensitivity to the active substance
• Severe liver disease or biliary obstruction
• Pregnancy (strictly contraindicated from the second trimester onward, as it can cause serious harm to the unborn child)
• Combination with aliskiren in patients with diabetes or renal impairment

Important interactions exist with:

• Potassium-sparing diuretics and potassium supplements (increased risk of hyperkalemia)
• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (may weaken the blood pressure-lowering effect)
• Lithium (possible increase in lithium blood levels)

Special Notes

In 2018, valsartan was the subject of a Europe-wide recall after the potentially carcinogenic impurity N-nitrosodimethylamine (NDMA) was detected in some batches of the active substance from certain manufacturing sources. The contamination was traced back to a change in the manufacturing process. Since then, quality control standards have been significantly tightened and affected products have been withdrawn from the market.

References

1. European Medicines Agency (EMA): Valsartan - Summary of Product Characteristics. Available at: https://www.ema.europa.eu (2024)
2. U.S. Food and Drug Administration (FDA): Valsartan Recalls - Information for Patients and Consumers. Available at: https://www.fda.gov (2024)
3. Mancia G et al. - 2023 ESH Guidelines for the Management of Arterial Hypertension. Journal of Hypertension, 2023.