Generic name: Losartan.

Other brand names: Hyzaar.

Cozaar is an angiotensin II receptor antagonist, a new class of blood pressure medications. It works by preventing the angiotensin II hormone from constricting the blood vessels, which usually raises blood pressure. 

Quick Facts About Cozaar


Used to control hypertension (high blood pressure). Effective when used alone or with other high blood pressure medications.

Cozaar Dosage

Take exactly as prescribed. Take at approximately the same time every day, with or without food. Do not discontinue use without consulting your doctor.

  • Usual adult dose: 50 milligrams once per day. May also be taken twice per day in doses ranging from 25 milligrams to 100 milligrams, as prescribed by your doctor.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Cozaar Side Effects

Overdose symptoms:

dizziness, faintness, light headedness, slow or irregular heartbeat. If you suspect an overdose, immediately seek medical attention.

More common side effects: headache.

Less common Cozaar side effects: back pain, diarrhea, dizziness, fatigue, stuffy nose, upper respiratory infection (cough, fever, sore throat). Rare side effects: dry cough, insomnia, indigestion, leg pain, muscle cramps, swelling of face, lips, and tongue.


Inform your doctor before combining Cozaar with:

ketoconazole (Nizoral) or troleandomycin (Tao).

Do not combine Cozaar with foods such as low-salt milk or salt substitutes containing potassium. Use alcohol or marijuana with caution.

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Potential benefits may outweigh potential risks. Appears in breast milk; could affect a nursing infant.

No special precautions apply to seniors.

Not recommended for children.

  • Do not discontinue use of Cozaar without consulting your doctor, even if you don’t feel well. Benefits of medication may take several weeks to appear.
  • May cause low blood pressure, especially when used in combination with a diuretic. Inform your doctor immediately if you experience a severe drop in blood pressure, indicated by dehydration, excessive sweating, severe diarrhea, or vomiting.
  • You may feel light-headed or faint, especially at the beginning of Cozaar therapy. Use caution when exercising or performing activities in hot weather.
  • Do not drive or operate machinery until adjusted to medication. Inform your doctor if these symptoms appear.
  • Cozaar may interfere with the accuracy of some medical tests. Inform any doctor or dentist of use.
  • Follow any special diet your doctor prescribes. It may help control hypertension.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Cozaar side effects, please contact your healthcare provider.