Losartan vs. Valsartan (Differences between Side Effects and Uses)

• Losartan and valsartan are angiotensin receptor blockers (ARBs) that work by blocking angiotensin II that causes blood vessels to constrict. This causes blood vessels to dilate which helps reduce blood pressure and the workload on the heart.
• Both losartan and valsartan are used to treat high blood pressure (hypertension).
• Losartan is also used to reduce the risk of stroke in patients with high blood pressure and left ventricular hypertrophy (enlarged heart muscle), to treat people with type 2 diabetes, and hypertensive patients with diabetic nephropathy (kidney disease).
• Valsartan is also used to treat heart failure and to reduce deaths in patients who developed congestive heart failure after a heart attack.
• Side effects of losartan and valsartan that are similar include:
  • Diarrhea
  • Dizziness
  • Fatigue
• Side effects of losartan that are different from valsartan include:
  • Chest pain
  • Insomnia
  • Low blood sugar (hypoglycemia)
  • Muscle cramps
  • Stuffy nose
  • Urinary tract infections (UTIs)
  • Weakness
• Side effects of valsartan that are different from losartan include:
  • Headache
  • Abdominal pain
  • Cough
  • Nausea
• Both losartan and valsartan may interact with:
  • Potassium-sparing diuretics
  • Potassium supplements
  • Salt substitutes containing potassium
• Nonsteroidal anti-inflammatory drugs (NSAIDs), for example:
  • Losartan may also interact with ACE inhibitors, aliskiren, and lithium.
  • ARBs including losartan and valsartan are not recommended for use during pregnancy; they can harm a fetus.
  • Because of the potential for adverse effects in nursing infants, ARBs such as losartan and valsartan are not recommended for use while breastfeeding.

Losartan

Losartan is a type of drug called an angiotensin receptor blocker (ARB). ARBs block a substance called angiotensin II that causes blood vessels to constrict. When angiotensin II is prevented from binding to angiotensin II receptors, blood vessels can widen (dilate) and relax. This helps reduce blood pressure and makes it easier for the heart to pump blood throughout the body.

Valsartan

Valsartan is also an angiotensin receptor blocker (ARB). It works in the same way as losartan, by preventing angiotensin II from binding to angiotensin II receptors, causing blood vessels to relax and dilate. This helps lower blood pressure and reduces strain on the heart.

Losartan uses

Losartan is used for treating hypertension, reducing the risk of stroke in patients with hypertension, and left ventricular hypertrophy (over developed heart muscle), and treating people with type 2 diabetes, and hypertensive patients with diabetic nephropathy (kidney disease). Losartan may be used alone or in combination with other drugs.

Valsartan uses

\Valsartan is used to treat high blood pressure and heart failure. It also is prescribed after heart attacks since valsartan may reduce deaths in patients who developed congestive heart failure after a heart attack. Valsartan also may reduce hospitalizations in patients with congestive heart failure.

Losartan

Losartan side effects include:

• Chest pain
• Diarrhea
• Dizziness
• Fatigue
• Insomnia
• Low blood sugar (hypoglycemia)
• Muscle cramps
• Nasal congestion
• Urinary tract infections (UTIs)
• Weakness

Losartan also may cause:

• A persistent cough
• An increase serum potassium (hyperkalemia)
• Impotence (erectile dysfunction, ED)

Losartan may reduce kidney function in some patients and should not be used by patients who have bilateral renal artery stenosis (narrowing of both arteries going to the kidneys).

Rare cases of rhabdomyolysis (muscle breakdown) have been reported.

Valsartan

Valsartan is generally well-tolerated. The most common side effects are:

• headache,
• dizziness,
• fatigue ,
• abdominal pain,
• cough,
• diarrhea and
• nausea.

Other important side effects are:

• hyperkalemia,
• impotence,
• reduced renal function, and
• allergic reactions.

Rhabdomyolysis (inflammation and destruction of muscle) and angioedema (swelling of soft tissues including those of the throat and larynx) are rare but serious side effects of valsartan.

Losartan dosage

• The starting dose of losartan for adults is 25-50 mg daily.
• The maximum dose is 100 mg daily. The total daily dose of losartan may be divided and administered two doses daily.
• The starting dose of losartan for pediatric patients 6 years of age or older is 0.7 mg/kg up to 50 mg once daily. Doses more than 1.4 mg/kg or 100 mg daily have not been
• Losartan may be given with or without food evaluated in pediatric patients.

The usual dose of valsartan for adults with high blood pressure is 80 to 160 mg once daily. The maximum dose is 320 mg daily. Maximum blood pressure reduction occurs within 4 weeks. For congestive heart failure, the usual dose is 40 mg twice daily. The doses may be increased to 80-160 mg twice daily. The initial dose after a heart attack is 20 mg twice daily. The dose may be increased to 160 mg twice daily if tolerated without side effects.

Valsartan dosage

The usual dose of valsartan for adults with high blood pressure is 80 to 160 mg once daily. The maximum dose is 320 mg daily. Maximum blood pressure reduction occurs within 4 weeks. For congestive heart failure, the usual dose is 40 mg twice daily. The doses may be increased to 80-160 mg twice daily. The initial dose after a heart attack is 20 mg twice daily. The dose may be increased to 160 mg twice daily if tolerated without side effects.

Losartan

Losartan may increase levels of blood potassium (hyperkalemia), which can lead to serious heart problems (arrhythmias). Therefore, concomitant use of other drugs or substances that increase blood-such as potassium-sparing diuretics (for example, spironolactone [Aldactone], triamterene, and amiloride), potassium supplements, or salt substitutes containing potassium may lead to dangerous increases in serum potassium.

Combining losartan or other ARBs with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients who are elderly, fluid-depleted (including those on diuretic therapy), or with poor kidney function may result in reduced kidney function, including kidney failure. These effects usually are reversible.

The antihypertensive effect of losartan may be reduced by aspirin and other NSAIDs such as:

• ibuprofen (Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc.),
• indomethacin (Indocin, Indocin-SR), and
• naproxen (Anaprox, Naprelan, Naprosyn, Aleve).

Combining ARBs, ACE inhibitors, or aliskiren (Tekturna) increases risk of hypotension (low blood pressure), hyperkalemia, and reduces kidney function compared to each drug used alone and there is no additional benefit on preventing end stage kidney disease or death.

Aliskiren and losartan should not be combined in patients with diabetes or with renal impairment.

Increases in blood lithium (Eskalith, Lithobid) levels and lithium toxicity have occurred when lithium and ARBs or hydrochlorothiazide were combined. Blood lithium levels should be monitored.

Valsartan

Combining valsartan with potassium-sparing diuretics (for example., spironolactone (Aldactone), triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to hyperkalemia (elevated potassium in the blood) and in heart failure patients, it increases serum creatinine, a blood test used for monitoring function of the kidneys.

Combining valsartan or other ARBs with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients who are elderly, fluid-depleted (including those on diuretic therapy), or with poor kidney function may result in reduced kidney function, including kidney failure. These effects are usually reversible. There have been reports that aspirin and other NSAIDs such as ibuprofen (Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, etc.), indomethacin (Indocin, Indocin-SR), and naproxen (Anaprox, Naprelan, Naprosyn, Aleve) may reduce the effects of ARBs.

Losartan safety

When used in the second or third trimester of pregnancy , ARBs can cause injury and even death to the fetus. Losartan should not be used during pregnancy. When pregnancy is first detected, losartan should be stopped.

It is not known whether losartan is excreted in breast milk, but losartan and its active form are excreted in rat milk. Due to the possibility of harm to the nursing infant, if possible, losartan should be discontinued by females who are nursing.

Valsartan safety

When used in the second or third trimester of pregnancy , valsartan and similar drugs can cause injury and even death to the fetus. Valsartan should not be used during pregnancy. When pregnancy is detected, valsartan should be stopped as soon as possible.

It is not known whether valsartan is secreted into human milk. Valsartan is secreted into the milk of rats.