Losartan contraindications and warnings


Following is information on contraindications to the use of losartan in general, pregnancy & amp; Breastfeeding and children. Please note that the contraindications may vary depending on the dosage form of a drug (eg tablet, syringe, ointment).

When should Losartan not be used?

In case of hypersensitivity to losartan, the active substance should not be used.

Due to a lack of therapeutic experience, the use of losartan in bilateral renal artery narrowing or unilateral renal artery stenosis is prohibited in patients with single kidney and in patients undergoing kidney transplantation. Also prohibited is treatment with losartan in severe hepatic impairment, valvular constriction, disease and thickening of the heart muscle (hypertrophic cardiomyopathy), as well as low blood pressure (

Patients with severe heart failure (NYHA Class IV), heart failure, concomitant severe renal impairment or life-threatening cardiac arrhythmia should not be treated with losartan.

Diabetic patients or patients with impaired renal function who receive the antihypertensive drug aliskiren should not be treated with losartan.

Patients with a heart attack in the last three days or patients with stress-independent chest pain (unstable angina pectoris) should also not receive losartan. Furthermore, stroke or transient circulatory disturbances in the last three months exclude treatment with losartan potassium.

In primary aldosteronism (impaired hormone secretion of the kidney), the use is generally not recommended. This condition does not respond to AT1 receptor antagonists.

Children should also not be treated with losartan. The same applies to pregnant women and nursing mothers.

Relative contraindications to the use of losartan are patients with coronary artery stenosis (coronary artery disease) or a fluid deficiency.

What should you watch out for during pregnancy and lactation?

Losartan should not be used during pregnancy and lactation.

AT1 receptor antagonists, including losartan, as well as ACE inhibitors in pregnancy after the formation of the child’s organs can affect their circulation and thus their development. Use in the second and third trimester of pregnancy may therefore cause renal dysfunction, a reduction in the amount of fruit water and slowing of cranial bone growth, and neonatal renal failure, low blood pressure, and excess blood potassium. The use of ACE inhibitors and AT1 receptor antagonists in the first trimester of pregnancy is not recommended due to lack of data from studies and is expressly prohibited in the period afterwards.

If pregnancy is suspected during pregnancy or pregnancy is planned, losartan should be discontinued as soon as possible.

Since it is not known whether the active substance passes into breast milk, mothers are not allowed to breastfeed during treatment. Therefore, the woman must abstive before starting therapy.

What should be considered in children?

The use of losartan is not recommended in children under the age of six because of limited experience in this group of patients. The dosage in children must be adjusted by the doctor to the body weight and the success of the blood pressure reduction.

Warnings and Precautions

  • Salt and / or fluid depletion should be corrected before therapy with the drug.
  • Pregnancy should be avoided in women of childbearing potential prior to use of the drug and should be prevented during treatment.
  • The dose of the drug should be slowly increased at the beginning of treatment (creeping dose).
  • An excessive drop in blood pressure may occur at the start of therapy and at any dose increase. Patients should therefore be monitored for three hours on such occasions.
  • Losartan potassium may cause a rise in blood potassium. Therefore, regular medical checks of the blood potassium content are necessary.
  • The drug is less effective in lowering blood pressure in black people than in fair-skinned patients.
  • Reactivity may be impaired by the drug to the extent that driving and operating machines are dangerous.

Sometimes medications release allergic reactions.
If you notice any signs of allergic reaction, tell your doctor or pharmacist immediately.