Are there any foods I should avoid while taking beta blockers?

No specific food contraindications or interactions have been noted for beta blockers.^1-11 Beta blockers such as carvedilol, labetalol, and metoprolol^9,12 should always be taken with food.

Grapefruit juice, however, should be consumed with caution when taking certain medications,¹³ as its interactions with cardiovascular drugs, such as beta blockers, can alter the pharmacokinetics and pharmacodynamics of the drugs.¹⁴ By interacting with important transporters and enzymes, such as organic anion transporting polypeptides (OATP)^15,16 and cytochrome P450s,^15,17 grapefruit juice, as well as orange and apple juice, can increase or decrease plasma levels of beta blockers. Concomitant administration of 200 to 600 mL of grapefruit, orange, or apple juice can decrease absorption¹⁸ of certain beta blockers, such as atenolol by about 40% and acebutolol by about 7%.

Grapefruit Juice

Studies have shown that grapefruit juice can increase or decrease the oral bioavailability of beta blockers.^17,19-22 Lilja et al. randomized participants to drink either 200 mL of grapefruit juice or water three times a day for three days, and twice on day 4.¹⁹ On day 3,400 mg acebutolol was orally administered. The study found that C_max (peak plasma concentration) of acebutolol was decreased by 19% (p<0.05) and that AUC (area under the concentration time curve) was decreased by 7% (p<0.05) on grapefruit juice, when compared to water. Another randomized trial by Lilja et al. studied the effect of itraconazole and grapefruit juice on the plasma concentrations of celiprolol. With grapefruit juice, the mean AUC of celiprolol decreased to 13% (p<0.01) and C_max decreased to 5% (p<0.001) of the respective placebo phase values. While grapefruit juice decreased bioavailability of some beta blockers,^19,20 it can increase bioavailability of carvedilol²¹ and may enhance drug toxicity.²² A manufacturer of carvedilol reports that drinking 300 mL of grapefruit juice can increase plasma carvedilol concentration¹⁷ by 16%.

Orange Juice

Studies have shown that orange juice can also change the bioavailability of beta blockers.^15,23,24 Another study by Lilja et al. randomized participants to drink either 200 mL of orange juice or water with 50 mg of atenolol.²³ They found that orange juice lowered C_max of atenolol by 49% (90% confidence interval [CI] [16 – 59], p<0.01) and AUC by 40% (90% CI [25 – 55], p<0.01) compared to the control, when measured up to 33 hours after drug administration. When Lilja et al.²⁴ randomized participants to drink either 200 mL orange juice or water three times a day for two days and administered 100 mg celiprolol on day three, they found that orange juice lowered C_max of celiprolol by 89% (p<0.01) and AUC by 83% (p<0.01) when compared to the control. 

Apple Juice

When participants were assigned to drink either 300 mL water, 600 mL or 1,200 mL apple juice while on atenolol,²⁵ the study found that apple juice reduced systemic exposure to atenolol in a dose-dependent fashion. 600 mL apple juice decreased atenolol AUC by 58% (95% CI [0.41 – 0.70]) and 1,200 mL by 82% (95% CI [0.75 – 0.87]), when compared to the control.

^References

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