Considering the patient's use of both loratadine and medroxyprogesterone acetate, which pharmacokinetic interaction is most likely to affect the efficacy of these medications?
Medroxyprogesterone acetate induces CYP2D6, reducing loratadine's effectiveness. Loratadine metabolism may be affected by CYP3A4 interactions, potentially altering its efficacy when used with medroxyprogesterone acetate. Loratadine inhibits COMT, affecting the metabolism of medroxyprogesterone acetate. Medroxyprogesterone acetate is metabolized by CYP1A2, which is inhibited by loratadine.