In a study of the interaction between the combination of darunavir / ritonavir and indinavir (800 mg twice daily) the plasma concentration of darunavir increased by 24% in the presence of indinavir and ritonavir; in the presence of the combination of darunavir / ritonavir concentrations increased by 23% in indinavir plasma. When used in conjunction with a combination masteron dosagedose ritonavir indinavir in patients who can not tolerate it may be reduced to 800 mg twice daily and 600 mg twice daily.
Other protease inhibitors
So far not studied the interaction between a combination ritonavir and protease inhibitors in addition to lopinavir, saquinavir, atazanavir and indinavir, and hence protease inhibitors is not recommended not listed here are used in conjunction with the combination of darunavir / ritonavir.
CCR5 receptor antagonists
With simultaneous use of a combination ritonavir maraviroc should be administered at a dose of 150 mg 2 times a day. In a study of the interaction between the combination of darunavir / ritonavir (600 mg / 100 mg twice daily) and maraviroc (150 mg 2 times a day), the concentration of maraviroc was increased by 305%. The effects of maraviroc concentration of darunavir / ritonavir was observed.
Recommendations on the simultaneous use of other classes of drugs
Drugs that reduce gastric acidity
Antacids (aluminum hydroxide / magnesium, calcium carbonate)
Not expected interaction between a combination ritonavir and antacids. The combination ritonavir and antacids can be used simultaneously without dose adjustment.
H2-histamine receptor blockers (cimetidine, famotidine, nizatidine, ranitidine)
Concurrent administration of ranitidine (150 mg 2 times a day) and a combination ritonavir (400/100 mg 2 times a day) had no effect on plasma concentration of darunavir in. Combination ritonavir and H2-receptor antagonists may be used simultaneously without dose adjustment.
Proton pump inhibitors (esomeprazole, lansoprazole, omeprazole, pantoprazole, rabeprazole)
Concomitant use of omeprazole (20 mg daily) and a combination ritonavir (400/100 mg 2 times a day) had no effect on plasma concentration of darunavir in. The combination ritonavir and a proton pump inhibitor can be used simultaneously without dose adjustment.
Antagonists of alpha 1-adrenergic receptors (alfuzosin)
Alfuzosin concentration in the plasma can be increased while the use of a combination ritonavir. Concomitant use of alfuzosin and the combination masteron dosage ritonavir is contraindicated.
Antianginal drugs (ranolazine)
The concentration of ranolazine in the plasma can be increased while the use of a combination ritonavir due to the inhibition isoenzymes. Concomitant use of ranolazine and a combination ritonavir is contraindicated.
Antiarrhythmic drugs (bepridil, disopyramide, dronedarone, mexiletine, systemic lidocaine, quinidine, amiodarone, flecainide, propafenone)
The combination ritonavir may increase serum concentrations of these antiarrhythmics. With simultaneous use of this combination and these antiarrhythmics it is recommended to be careful and, if possible, to monitor the concentrations of these agents in plasma. Concomitant use of a combination of Prezista ® / ritonavir, with amiodarone, bepridilom, dronedarone, quinidine and lidocaine when administered systemically.
In all studies on the interaction of a combination masteron dosageritonavir (600/100 mg 2 times a day) and a single dose of digoxin (0.4 mg) was shown to increase the final concentration of digoxin in plasma by 77%. It is recommended to initially prescribe the lowest dose of digoxin and measure serum concentration to obtain the desired clinical effect while the use of a combination ritonavir.