The study of interaction of a combination ritonavir with buprenorphine / naloxone combination demonstrated no effect ritonavir, the concentration of buprenorphine in their joint application. The concentration of the active metabolite of buprenorphine – norbuprenorfina increased by 46%. Dose adjustment of buprenorphine is not required. When sharing a combination ritonavir, and buprenorphine is recommended to conduct a careful clinical monitoring.
Estrogen-containing oral contraceptives
Results of research on the interaction between a combination masteron prop ritonavir (600/100 mg 2 times a day) and ethinyl estradiol and norethisterone indicate that constant plasma concentration of ethinyl estradiol and norethisterone, respectively reduced by 44% and 14%. Therefore, it is recommended to use alternative non-hormonal methods of contraception.
Inhibitors of phosphodiesterase type 5 (PDE-5)
In the treatment of erectile dysfunction (avanafil, sildenafil, tadalafil, vardenafil)
One study investigated sildenafil concentration after a single dose of the drug (100 mg), and after ingestion of 25 mg of sildenafil simultaneously with a combination darunavir / ritonavir (400 mg / 100 mg twice a day). Sildenafil concentrations were similar in both situations. Use caution while using PDE-5 inhibitors for the treatment of erectile dysfunction and combinations ritonavir. If necessary, use and ritonavir simultaneously with sildenafil, vardenafil or sildenafil tadalafil single dose not exceed 25 mg for 48 hours, a single dose of vardenafil should not exceed 2.5 mg per 72 hours, and a single dose of tadalafil should not exceed 10 mg over 72 h. The simultaneous use of a combination not recommended / ritonavir and avanafila.
In the treatment of pulmonary arterial hypertension (sildenafil, tadalafil)
A safe and effective dose of sildenafil for the treatment of pulmonary arterial hypertension, while the use of a combination of Prezista ® / ritonavir has not been established. There is an increased risk of side effects of sildenafil (including visual disturbances, hypotension, prolonged erection, and syncope). Thus, the simultaneous use of a combination Prezista ® / ritonavir and sildenafil in pulmonary hypertension therapy is contraindicated. For the treatment of pulmonary arterial hypertension tadalafil while the use of a combination ritonavir is required change doses of tadalafil. For patients receiving the combination ritonavir for at least one week, the initial dose of tadalafil should be 20 mg 1 time per day with a possible increase to 40 mg 1 time a day based on individual tolerability. For patients receiving tadalafil and beginners combination therapy ritonavir should be discontinued tadalafil at least 24 hours prior to initiation of therapy, a combination ritonavir and should avoid the simultaneous use of tadalafil during initiation of therapy, a combination ritonavir. After 1 week after initiation of therapy, a combination of ritonavir should resume tadalafil at a dose of 20 mg 1 time per day with a possible increase to 40 mg 1 time per day based on individual tolerability.