Drug Detail:Valsartan (Valsartan [ val-sar-tan ])
Drug Class: Angiotensin receptor blockers
1. How it works
- Valsartan may be used to treat high blood pressure.
- Valsartan works by blocking the binding of angiotensin II to the AT1 receptor in various tissues, such as those of the blood vessels and adrenal gland. Angiotensin II is a powerful vasoconstrictor (narrows blood vessels), that is also involved in the synthesis and release of aldosterone (the main steroid hormone produced by the adrenal gland). By inhibiting the actions of angiotensin II, valsartan opens up the arteries (vasodilates) and lowers blood pressure.
- Valsartan belongs to a group of medicines known as angiotensin II receptor antagonists (also called angiotensin II receptor blockers or ARBs).
2. Upsides
- May be used for the treatment of high blood pressure (hypertension) or heart failure (NYHA class II-IV).
- May also be given after a heart attack to reduce the risk of death.
- May be given to children over the age of six with pediatric hypertension (tablets may be added to an oral suspending vehicle to make a liquid suspension).
- Generic valsartan is available.
3. Downsides
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- A headache, dizziness, fatigue, and increased blood levels of potassium are the most common side effects.
- May cause a dry cough. The risk is higher in people who have experienced other drug-induced coughs, such as with ACE inhibitors.
- May also cause gastrointestinal disturbances, sinusitis, stuffy nose, low sodium levels, joint pain, back pain and muscle cramps.
- Rarely, may cause excessive lowering of blood pressure but the risk is higher in those on diuretic therapy or who are sodium depleted or dehydrated.
- Rarely may cause angioedema of the face, lips, tongue, throat, and extremities. May occur at any time during treatment. Immediate discontinuation is warranted if angioedema is affecting breathing.
- Valsartan may not be suitable for some people with certain pre-existing kidney conditions, liver disease, severe heart failure, or dehydration; or increased monitoring may be required.
- May interact with a number of other drugs including lithium, aliskiren, NSAIDs, and potassium supplements.
- Not recommended for children younger than six or children with certain kidney problems.
- Can cause severe birth defects and fetal death if used during pregnancy. Tablets should not be given to pregnant women and should be discontinued immediately if pregnancy is detected.
Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects
4. Tips
- Valsartan is usually given once or twice daily.
- May be taken with or without food.
- Report any signs or symptoms of angioedema (swelling of face or throat, difficulty breathing) immediately to your doctor.
- May cause a fall in blood pressure that may be noticed as light-headedness; call your doctor and ask for advice, symptoms usually resolve with continued therapy. Ensure you do not become dehydrated.
- Do not use salt substitutes containing potassium without first consulting your doctor.
- Valsartan is usually used in addition to other drugs to lower blood pressure, and all lifestyle recommendations given to you by your doctor (such as losing weight if overweight, smoking cessation, partaking in regular exercise, and limiting sodium intake) should also be followed. In addition, other conditions, such as high cholesterol levels or diabetes if present, also need to be controlled.
- Do not take any other medications including those bought over-the-counter without checking with your doctor or pharmacist that they are compatible with valsartan.
- Tell your doctor if you are pregnant or intending to become pregnant as valsartan is not suitable for pregnant women because it can cause birth defects. Small amounts are also excreted into breastmilk.
5. Response and effectiveness
Peak concentrations of valsartan occur within two to four hours of dosing. May take up to two weeks for substantial blood pressure-lowering to occur; peak blood pressure-lowering effects are attained after four weeks. Some doctors may use a higher dosage initially or add a diuretic (water pill) if faster blood pressure reduction is required. Blood pressure lowering effects of a daily dose are maintained for at least 24 hours.
6. Interactions
Medicines that interact with valsartan may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with valsartan. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.
Common medications that may interact with valsartan include:
- antipsychotics, such as aripiprazole, clozapine, or haloperidol
- aspirin
- bupropion
- buprenorphine
- corticosteroids, such as budesonide, betamethasone, or prednisone
- cyclosporine
- heart medications, such as amiloride, atenolol, benazepril, captopril, fosinopril, lisinopril, or metoprolol
- insulin
- other medications including celecoxib, clonidine, hydralazine, and rifampicin
- NSAIDs, such as diclofenac, ibuprofen, or indomethacin
- potassium salts
- sildenafil
- trimethoprim
- zolpidem.
People taking oral medications for diabetes may need to talk to their doctor about adjusting the dose of their medicine.
Note that this list is not all-inclusive and includes only common medications that may interact with valsartan. You should refer to the prescribing information for valsartan for a complete list of interactions.