The interaction between coffee and antihypertensive drugs: the growth and decline of each other?

There is no support or objection in the hypertension guidelines on whether you can drink coffee while taking antihypertensive drugs.

A recent meta-analysis indicated that the short-term pressor effect of caffeine may reduce the efficacy of antihypertensive drugs and called for formal research to explore the interaction between coffee and specific antihypertensive drugs in order to clearly recommend them in the guidelines.

This is a recent randomized, single-dose, crossover study conducted by Canadian scholar David G. Bailey and colleagues to determine whether the pressor effect of coffee is offset by felodipine, a CCB drug (sustained-release type).

The subjects were middle-aged people with normal blood pressure. They were divided into three groups. After abstaining from drinking coffee and fasting caffeinated food for 2 days, they were given black coffee (2300 ml), 10 mg felodipine (maximum recommended dose) and coffee plus felodipine, respectively, and their hemodynamic and pharmacokinetic effects were evaluated.

Main results

In the coffee group, the blood pressure was higher than the baseline within 1-4 hours after drinking coffee. Brachial artery systolic blood pressure, brachial artery diastolic blood pressure, aortic systolic blood pressure, aortic pulse pressure and aortic enhanced pressure increased by 7.6 mmHg (P < 0.001), 4.9 mmHg (P < 0.001), 7.4 mmHg (P < 0.001), 3.0 mmHg (P < 0.001) and 1.4 mmHg (P < 0.001), respectively.

However, part of the blood pressure in the coffee + felodipine group was higher than that in the felodipine group, and the brachial artery systolic blood pressure, diastolic blood pressure and aortic systolic blood pressure increased by 4.0 mmHg (P < 0.001), 3.9 mmHg (P < 0.001) and 4.6 mmHg (P < 0.001), respectively.

The pressor effect of coffee and its counteraction with felodipine vary from person to person. Coffee containing 127 mg caffeine had the greatest pressor effect.

The pharmacokinetics of caffeine and felodipine are similar either alone or in combination, which indicates that their interactions have the same pharmacokinetic basis.

The plasma concentration of felodipine is related to its effect on reducing diastolic blood pressure, and this relationship can be changed by drinking coffee. Twice the dose of felodipine can counteract the pressor effect of coffee. However, this may increase the risk of adverse drug reactions, especially on days when you don't drink coffee.

Summary

Overall, caffeine in the body can be basically eliminated after drinking coffee for 2 days.

After drinking coffee for an hour, the vasoconstrictive effect is the strongest, and this effect may last for several hours. But clinically, these few hours may be critical for some people.

Pharmacokinetic interaction between coffee and 10 mg felodipine.

For most people, drinking coffee regularly may complicate the diagnosis and management of high blood pressure.