A new study, published in Clinical Pharmacology & Therapeutics, examined the effects of green tea on how the body processes the beta blocker nadolol.  After repeated consumption of either green tea or water, healthy volunteers received a dose of nadolol.  Researchers found that those participants that consumed green tea before receiving the medication had a lower blood plasma concentration of the drug.  According to American Live Wire, these results indicate that drinking tea may actually lessen the efficacy of the drug nadolol commonly prescribed for treating high blood pressure.

Tech Times reports that follow-up studies, including lab tests, revealed that green tea blocks a drug transporter found in the lining of the human gut that helps transport nadolol from the gut into the cells, where it can work on reducing blood pressure.  Researchers working on this study have encouraged advising patients on nadolol and similar medications not to drink tea while on the medication.  However, further studies are needed to understand the nature of the relationship between green tea and nadolol.

For patients that really want to drink tea, it is advisable to leave at least a four-hour gap between consuming tea and taking the medication.  This time gap is not established on clinical evidence.  However, there is anecdotal evidence that leaving four hours would improve the uptake of medication.  This is based on a similar relationship involving grapefruit consumption.

According to the Mayo Clinic, beta blockers are a class of medication that treat a variety of diseases including high blood pressure, migraines, and glaucoma.  Beta blockers work by blocking the effects of the hormone epinephrine, also known as adrenaline.  This causes the heart to beat slower and with less force.  Beta blockers also help blood vessels open up to improve blood flow.

The Centers for Disease Control and Prevention (CDC) reports that there are 67 million American adults with high blood pressure.  This condition puts individuals at risk for heart disease and stroke.  Of individuals who have had a first heart attack, 69 percent suffer from high blood pressure.  An estimated 348,000 annual deaths in the U.S. included high blood pressure as a primary or a contributing cause.

In order to prevent and control high blood pressure, lifestyle changes are necessary, according to the Mayo Clinic.  Lifestyle changes include decreasing sodium intake, maintaining a healthy weight, increasing physical activity, not using tobacco, limiting alcohol intake, home monitoring of blood pressure, and managing stress levels through lifestyle modification and relaxation practice.