No pharmaceutical opinion available for this interaction.
Ritonavir can inhibit the metabolism (CYP 3A4) and increase the plasma concentration of Ritonavir.
3A4 and 2D6 (major), 1A2 and 2B6 (minor), 5 metabolites, one of which has a weak concentration of an active metabolite (M-2), transporters: MRP1, MRP2, P-gp
2B6, 2C8, 2C9, 1A2, 2C19 (moderate) UGT (moderate)
3A4 (potent) and 2D6 (moderate), transporters: BCRP, OATP1A2, OATP1B1, OATP1B3, MRP1, MRP2, OCT1, OCT2, P-gp
Possible increase of adverse effects.
Avoid association. Choose an alternative.
Beclomethasone 100 ug = mometasone 200 ug.
Mometasone toxicity : Cushing's syndrome (moon face, buffalo hump, obesity, striations, acne, hirsutism, hypertension, osteoporosis, glucose intolerance, increased risk of infections) and adrenal suppression (melanodermia, fatigue, weakness, hypotension, weight loss, digestive disorders).
Ref #3412 : Case report of a 54 year-old VIH+ woman on tenofovir, raltegravir and darunavir/ritonavir who developed severe unrecognized exogenous Cushing’s syndrome from the concomitant administration with the potent inhaled glucocorticoid mometasone.
The accumulation of corticosteroids can cause Cushing's syndrome (moon face, excitation/insomnia, hypertension, increased appetite and weight, ease of doing bruising) and potentially a suppression of the hypothalamic-pituitary axis, which could lead to adrenal insufficiency.
The safest corticosteroid is beclomethasone (Qvar) since its metabolism is mainly by an esterification mechanism.
Ref #2550 and #2551 : A cross-sectional study (n = 11 783) suggests lower prevalence of adrenal insufficiency with beclomethasone than with other corticosteroids currently available on the market. Pharmacokinetic studies with beclomethasone and ritonavir or combination darunavir/ritonavir demonstrated that there were no clinically significant pharmacokinetic interactions. No variation of blood cortisol have been observed.