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Green Tea May Reduce Effectiveness of Meds

Green Tea may reduce the effectiveness of medication used to lower your blood pressure. A new study published in the journal Clinical Pharmacology & Therapeutics Jan. 13 found that drinking tea may actually lessen the efficacy of the drug nadolol commonly prescribed for treating high blood pressure per Tech Times.

Green Tea May Reduce Effectiveness of Meds

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Researchers recruited ten adults and gave them a single dose of 30 milligrams of nadolol after drinking three cups of green tea or water every day for two weeks. When the volunteer’s blood was tested, they found the concentration of nadolol was 76 percent lower compared to those that drank water. They also found that the amount of nadolol detected in the urine was approximately 80 percent lower among those who drank green tea regularly.The results concluded that green tea may reduce the ability for nadolol to be absorbed well by the body. Follow up lab tests showed that green tea blocks a drug transporter found in the lining of the gut that helps transport nadolol from the gut into the cells, where it works on reducing blood pressure.

Researchers acknowledged that further studies will need to be conducted to understand how green tea may react with drugs like nadolol but they have advised patients currently taking nadolol to avoid drinking green tea.

“Individuals who take nadolol and also consume green tea should be aware of this potential interaction and discuss this with their physician,” said Dr. Gregg Fonarow, a professor of cardiology at the University of California in Los Angeles and spokesman for the American Heart Association.

Sotiris Antoniou, spokesman for the Royal Pharmaceutical Society and consultant pharmacist in cardiovascular medicine recommended a way to get around this. He advised high blood pressure patients who still need their green tea fix to leave a four-hour gap in between cups and taking their medication.

About Chelsea Alves

  • Winterbourne

    Thats one interpretation with one specific drug. My interpretation: caffeine is a diuretic, causing you to urinate more. Thus, you’re going to filter out more from your bloodstream, due to increased volume. The urine will also carry less proportionally, as there is, once again, more volume of water.

    • tengig

      That doesn’t make any sense. If you “filter out more from your blood”, then there should be more in the urine, even with the increase in urination, not less. You can’t have less in both places. Besides, that’s not how caffeine works as a diuretic.

      • Winterbourne

        Sure it does:

        Because by removing more waste volume, a greater volume of the drug is removed. However, due to the effects of the diuretic, you’d be peeing more water, thus the concentrations would be lower in the pee.

        It’s the walmart principle: A smaller percentage of a larger volume can result in more overall.

        Caffeine works by inhibiting sodium reuptake as well as increasing glomerular filtration rate. You increase the rate by increasing the amount of water that flows through the pipes and decreasing how much gets reabsorbed before the urine leaves the kidneys.

        • tengig

          No, you’re still not making sense. You’re trying to have it both ways. If you remove more of the drug from the blood, then the concentration in pee would be higher. But since you’re also filtering more water, then it’s basically a wash. The concentration in the blood would be reduced without significantly reducing the concentration in urine.

          The reasonable explanation is that the green tea is inhibiting transfer of the chemical into the blood in the first place, while also increasing filtration rate, ergo a reduction in both systems. It’s not just caffeine.