Losartan is part of a class of drugs called angiotensin II receptor blockers. As the name of its drug class implies, losartan blocks angiotensin II receptors. This decreases the effectiveness of a chemical known as angiotensin II, which normally causes blood vessels to narrow (constrict). By blocking the effects of angiotensin II, the medication causes blood vessels to relax, which can lower blood pressure.
A blood pressure reading consists of two numbers -- for example: 120/80. The top number is known as the systolic blood pressure, and the bottom number is the diastolic blood pressure. During clinical studies in people taking losartan, systolic blood pressure (the top number) decreased, on average, by 5.5 to 10.5 mmHg. Diastolic blood pressure (the bottom number) decreased by 3.5 to 7.5 mmHg, on average. Certain factors, such as dosage, affected how much the blood pressure dropped.
By lowering blood pressure, the medication can decrease the risks that are seen with long-term high blood pressure (see Effects of High Blood Pressure). This includes a stroke or heart attack.
For people with diabetic nephropathy, the effects of losartan have been shown to slow the progression of diabetic nephropathy, resulting in less kidney damage and a decreased chance for developing serious complications (such as the need for kidney dialysis).
Some general considerations for when and how to take this medication include:
- Losartan comes in tablet form. It is usually taken once or twice a day.
- It may be taken with or without food.
- Losartan should be taken at the same time each day to maintain an even level of medicine in your blood.
- For the medicine to work properly, you have to take it as prescribed. It will not work if you stop taking it.