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 losartan for treatment of diabetic nephropathy, common side effects include fatigue, anemia, and diarrhea. If you develop any serious losartan side effects such as itching, wheezing, or difficulty swallowing, be sure to seek medical attention immediately.

 

Losartan Side Effects: An Overview

As with any medicine, there are possible side effects with losartan potassium (Cozaar®). However, not everyone who takes losartan will experience side effects. In fact, most people tolerate losartan well. When 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 can occur, but are less common.
 
(The side effects discussed below are not a complete list of side effects reported with losartan. Your healthcare provider can discuss a more complete list of losartan side effects with you.)
 

Common Side Effects of Losartan

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 side effects 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).
     
(Losartan Side Effects Continued: Page 2)
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;