Do not use if you are pregnant. Stop using and tell your doctor right away if you become pregnant. Losartan can cause injury or death to the unborn baby if you take the medicine during your second or third trimester. Use effective birth control.
You should not use this medication if you are allergic to losartan.
If you have diabetes, do not use losartan together with any medication that contains aliskiren (Amturnide, Tekturna, Tekamlo, Valturna).
In extremely rare cases, losartan can cause a condition that results in the breakdown of skeletal muscle tissue, potentially leading to kidney failure. Call your doctor right away if you have unexplained muscle pain, tenderness, or weakness especially if you also have fever, unusual tiredness, and dark colored urine.
Before taking this medicine
You should not use losartan if you are allergic to it.
If you have diabetes, do not use losartan together with any medication that contains aliskiren (Amturnide, Tekturna, Tekamlo, Valturna). You may also need to avoid taking this medicine with aliskiren if you have kidney disease.
To make sure losartan is safe for you, tell your doctor if you have:
kidney disease;
liver disease;
congestive heart failure;
an electrolyte imbalance (such as low levels of potassium in your blood); or
if you are dehydrated.
FDA pregnancy category D. Do not use if you are pregnant. Stop using and tell your doctor right away if you become pregnant. Losartan can cause injury or death to the unborn baby if you take the medicine during your second or third trimester. Use effective birth control.
It is not known whether losartan passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.
 Losartan pregnancy and breastfeeding warnings (more detail)
How should I take losartan?
Take losartan exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
You may take losartan with or without food.
Call your doctor if you have ongoing vomiting or diarrhea, or if you are sweating more than usual. You can easily become dehydrated while taking this medication, which can lead to severely low blood pressure or a serious electrolyte imbalance.
Your blood pressure will need to be checked often. Visit your doctor regularly.
It may take 3 to 6 weeks of using losartan before your blood pressure goes down somewhat. For best results, keep using the medication as directed. Talk with your doctor if your symptoms do not improve after 3 weeks of treatment.
If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.
Store at room temperature away from moisture, heat, and light.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
