May 23 2022

Active ingredient: atenolol

Atenolol is rapidly but incompletely absorbed from the gastrointestinal tract; it is estimated that the fraction that pass into the body is 50% [1]. The time to reach peak concentration is 2-4 hours (Tmax), although there is considerable variability between different people.

According to data from studies in healthy volunteers, oral administration of atenolol with foods produces at first shortening the time it takes to reach maximum concentration (Tmax), but reduces the total absorption of the drug by 20%, as evidenced by the reduction in the area under curve (AUC0-33h) [2].

More pronounced is the influence of orange or apple juices, that can cause decreased peak plasma concentration of atenolol by 49% and an overall reduction in AUC and absorbing by 40% when taken at the same time that atenolol. This effect may have clinical relevance[3][4][5].

Absorption of atenolol is also influenced by taking antacids[1].

For these reasons, it is recommended taking atenolol without food, avoiding specially orange or apple juices, from two hours before until two hours after taking the drug.


1: Kirch W, G?rg KG. Clinical pharmacokinetics of atenolol--a review.Eur J Drug Metab Pharmacokinet. 1982;7(2):81-91.
2: Melander A, Stenberg P, Liedholm H, Scherst?n B, W?hlin-Boll E.Food-induced reduction in bioavailability of atenolol.Eur J Clin Pharmacol. 1979 Nov;16(5):327-30.
3: Lilja JJ, Raaska K, Neuvonen PJ.Effects of orange juice on the pharmacokinetics of atenolol.Eur J Clin Pharmacol. 2005 Jul;61(5-6):337-40.
4: Jeon H, Jang IJ, Lee S, Ohashi K, Kotegawa T, Ieiri I, Cho JY, Yoon SH, Shin SG, Yu KS, Lim KS.Apple juice greatly reduces systemic exposure to atenolol. Br J Clin Pharmacol. 2013 Jan;75(1):172-9. doi: 10.1111/j.1365-2125.2012.04324.x.
5: Bailey DG. Fruit juice inhibition of uptake transport: a new type of food-drug interaction. Br J Clin Pharmacol. 2010 Nov;70(5):645-55. doi: 10.1111/j.1365-2125.2010.03722.x.