The risk of myopathy during treatment with HMG-CoA reductase inhibitors increases with simultaneous use of cyclosporine, fibrates, erythromycin, clarithromycin, antifungal agents - azole derivatives, - and nicotinic acid in lipid-lowering doses (see section "Special instructions").
Inhibitor inhibitors CYP3A4
Because the atorvastatin is metabolized by isoenzyme CYP3A4, simultaneous use of atorvastatin with isozyme inhibitors CYP3A4 can lead to an increase in the concentration of atorvastatin in the blood plasma. The degree of interaction and the effect of potentiation are determined by the variability of the effect on the isoenzyme CYP3A4. The simultaneous use of atorvastatin with drugs that reduce the concentration of endogenous steroid hormones (including cimetidine, ketoconazole, spironolactone) increases the risk of reducing endogenous steroid hormones.
Inhibitors of transport protein OATP1B1
Atorvastatin and its metabolites are substrates of the transport protein OATP1B1. Inhibitors of OATP1B1 (for example, ciclosporin) may increase the bioavailability of atorvastatin. Thus, simultaneous use of atorvastatin 10 mg and cyclosporine at a dose of 5.2 mg / kg / day leads to an increase in the concentration of atorvastatin in blood plasma by 7.7 times (see the section "Method of administration and dose").
Erythromycin / clarithromycin
With simultaneous use of atorvastatin and erythromycin (500 mg 4 times a day) or clarithromycin (500 mg twice a day), which inhibit the isoenzyme CYP3A4, an increase in the concentration of atorvastatin in the blood plasma was observed (see section "Special instructions").
HIV protease inhibitors
The simultaneous use of HIV protease inhibitors (fosamprenavir, nelfinavir, lopinavir / ritonavir, saquinavir / ritonavir, darunavir / ritonavir, fosamprenavir / ritonavir) with atorvastatin leads to an increase atorvastatin plasma concentration.
Hepatitis C protease inhibitors
Protease inhibitors of hepatitis C (boseprevir) while the application of atorvastatin, atorvastatin leads to an increase in concentration in the blood plasma.
Diltiazem
Simultaneous use of atorvastatin in a dose of 40 mg with diltiazem in a dose of 240 mg, leads to an increase in the concentration of atorvastatin in blood plasma.
Cimetidine
Clinically significant interaction of atorvastatin with cimetidine was not detected.
Itraconazole
The simultaneous use of atorvastatin in doses of 20 mg to 40 mg and itraconazole at a dose of 200 mg resulted in an increase in the value AUC atorvastatin.
Grapefruit juice
Because grapefruit juice contains one or more components that inhibit the isoenzyme CYP3A4, its excessive consumption (more than 1.2 liters per day) can cause an increase in the concentration of atorvastatin in the blood plasma.
Inductors of cytochrome isoenzyme CYP3A4
Combined use of atorvastatin with isoenzyme inducers CYP3A4 (eg, efavirenz, rifampicin, phenytoin) can lead to a decrease in the concentration of atorvastatin in the blood plasma. Due to the dual mechanism of interaction with rifampicin (isoenzyme inducer CYP3A4 and inhibitor of hepatocyte transport protein OATP1B1), simultaneous use of atorvastatin and rifampicin is recommended, since delayed administration of atorvastatin after taking rifampicin results in a significant decrease in the concentration of atorvastatin in blood plasma.
Antacids
Simultaneous ingestion of a suspension containing magnesium hydroxide and aluminum hydroxide reduced the concentration of atorvastatin in the blood plasma by approximately 35%, but the degree of decrease in the concentration of LDL-C was not changed.
Fenazone
Atorvastatin does not affect the pharmacokinetics of phenazone, therefore interaction with other drugs metabolized by the same isoenzymes of cytochrome is not expected.
Kolestypol
With the simultaneous use of colestipol, the concentration of atorvastatin in the blood plasma decreased by about 25%; however, hypolipidemicthe effect of a combination of atorvastatin and colestipol was superior to that of each drug alone.
Digoxin
With repeated administration of digoxin and atorvastatin at a dose of 10 mg, the equilibrium concentrations of digoxin in the blood plasma did not change. However, when using digoxin in combination with atorvastatin in a dose of 80 mg / day. the digoxin concentration increased by about 20%. Patients receiving digoxin in combination with atorvastatin, require appropriate monitoring.
Azithromycin
With the simultaneous use of atorvastatin at a dose of 10 mg 1 time per day and azithromycin at a dose of 500 mg per day, the concentration of atorvastatin in the blood plasma did not change.
Oral contraceptives
With simultaneous use of atorvastatin and oral contraceptive containing norethisterone and ethinyl estradiol, there was a significant increase AUC norethisterone and ethinyl estradiol by about 30% and 20%, respectively. This effect should be considered when choosing an oral contraceptive for a woman receiving atorvastatin.
Terfenadine
With the simultaneous use of atorvastatin and terfenadine, clinically significant changes in the pharmacokinetics of terfenadinerevealed.
Warfarin
There were no signs of a clinically significant interaction of atorvastatin with warfarin.
Amlodipine
With simultaneous use of atorvastatin in a dose of 80 mg and amlodipine at a dose of 10 mg, the pharmacokinetics of atorvastatin did not change in the equilibrium state.
Fusidic acid
With the simultaneous use of atorvastatin with fusidic acid, the risk of rhabdomyolysis increases. With their simultaneous use, the concentration of both fusidic acid and atorvastatin in the blood plasma can be increased. The mechanism of this interaction is still not known. If treatment with fusidic acid is necessary, treatment with atorvastatin should be discontinued.
Colchicine
Caution should be exercised with the simultaneous use of atorvastatin with colchicine, since cases of myopathy have been described.