Cozaar is the prescription brand name for the drug losartan. Cozaar is prescribed for people with high blood pressure or hypertension. The National Institutes of Health says that the drug is also used to decrease the risk of stroke in patients with left ventricular hypertrophy, an enlargement of the walls of the left side of the heart. You should not eat grapefruit if you take Cozaar. Grapefruit or grapefruit juice may increase your risk of side effects from the drug.
Do Not Combine Grapefruit and Cozaar
Clinical nutrition specialist Jonny Bowden says in his book "The 150 Healthiest Foods on Earth" that you should not eat grapefruit while taking prescription medications such as blood pressure-reducing drugs like Cozaar. Bowden says that combining grapefruit or grapefruit juice with anti-hypertension medications will increase your risk for side effects. Certain compounds in grapefruit decrease your body's ability to properly eliminate medications from your system, increasing the potential for overdose.
Increased Side Effects
Eating grapefruit while taking Cozaar will increase the likelihood that you may experience Cozaar's potential side effects. A common side effect of blood pressure-reducing medications such as Cozaar is hypotension, or low blood pressure. If you take too much Cozaar, or in this case, if too much Cozaar is active in your system for an extended period of time, you may experience hypotension. Symptoms of low blood pressure include feeling like you might pass out, pain when urinating, pale skin, lightheadedness, chest pain, wheezing, irregular health beat, muscle weakness and weak pulse. Other side effects include dry cough, flu-like symptoms, stomach pain, headache and insomnia.
Bowden says that grapefruit works to extend how long prescription medications such as Cozaar are active in your body. Grapefruit contains three specific compounds called furocoumarins. These compounds inhibit the CYP3A4 enzyme, which is responsible for breaking down certain prescription medications and many hypertension medications in the liver. When your CYP3A4 enzyme is inhibited, Cozaar will not be metabolized as quickly and higher concentrations of the drug will be active for longer periods of time.
Other Foods to Avoid
If you have high blood pressure you may be using salt-substitutes. Drugs.com explains that if you are taking Cozaar you should avoid salt-substitutes that contain potassium, as it may lead to an unsafe level of potassium in your blood. Symptoms of high potassium may include an irregular heartbeat, confusion, weakness, tingling and a sensation of heaviness in your legs. If you are on Cozaar and experience any of these symptoms, contact your doctor at once.