Losartan Side Effects
The most common side effects seen in people taking losartan for high blood pressure include back pain, infection, and dizziness. In people taking the drug to treat diabetic nephropathy, common side effects include fatigue, anemia, and diarrhea. If you develop any serious side effects of losartan, such as itching, wheezing, or difficulty swallowing, be sure to seek medical attention right away.
As with any medicine, side effects are possible with losartan potassium (Cozaar®). However, not everyone who takes the drug will experience problems. In fact, most people tolerate it well. If side effects do occur, they are generally minor and either require no treatment or can easily be treated by you or a healthcare provider. Serious side effects are less common.
(This article covers most, but not all, losartan side effects. Your healthcare provider can discuss a more complete list of side effects with you.)
Losartan has been studied extensively in clinical trials, with thousands of people worldwide having been evaluated. In these studies, side effects are always documented and compared to those that occur in a similar group of people not taking the medicine. Based on these studies, the most common losartan side effects seen in people with high blood pressure include:
- Infection, such as the common cold or flu -- in up to 8 percent of people
- Dizziness -- up to 3 percent
- Nasal congestion -- up to 2 percent
- Back pain -- up to 2 percent.
In people with diabetic nephropathy, common side effects with losartan include:
- Diarrhea -- up to 15 percent of people
- Fatigue -- up to 14 percent
- Anemia -- up to 14 percent
- Increase in blood potassium levels -- up to 7 percent
- Low blood pressure -- up to 7 percent
- Weight gain -- up to 4 percent (see Cozaar and Weight Gain).