May 23 2022

Active ingredient: montelukast

The active ingredient montelukast is rapidly absorbed after oral administration in fasting, reaching peak concentration in 2-4 hours, depending on the presentation form used. Taking montelukast with a high fat meal does not alter the extent of absorption (area under curve), but reduces the maximum concentration and prolongs the time it takes to reach maximum concentration (Tmax) substantially (35%). Other observations indicate that administration of chewable tablets after a meal, reduces the bioavailability of montelukast from 73% in fasting to 63% after a standard breakfast.

The taking of montelukast with grapefruit juice produces a significant increase in drug concentration, probably due to metabolic inhibition of CYP450. In contrast, the lemon juice seems to have no influence on concentration or bioavailability of montelukast[1][2].

In short, montelukast is not affected substantially by taking it with or without food, except chewable tablets, although even here no clinical significance.


1. Cingi C, Toros SZ, G?rb?z MK, Ince I, Cakli H, Erdogmus N, Karasulu E, Kaya E.Effect of grapefruit juice on bioavailability of montelukast.Laryngoscope. 2013 Apr;123(4):816-9. doi: 10.1002/lary.23700.
2: Mougey EB, Lang JE, Wen X, Lima JJ.Effect of citrus juice and SLCO2B1 genotype on the pharmacokinetics of montelukast.J Clin Pharmacol. 2011 May;51(5):751-60. doi: 10.1177/0091270010374472. Epub 2010 Oct 25.