When combined use of atorvastatin with a number of drugs - ciclosporin, HIV protease inhibitors (indinavir, saquinavir, lopinavir, ritonavir, nelfinavir), erythromycin, clarithromycin, antifungal. preparations from the group of azoles (itraconazole, ketoconazole, fluconazole), nefazodone, derivatives of fibroic acid (gemfibrozil), a nicotinic acid in lipid-lowering doses, ezetimibe - concentration Atorvastatin in the blood plasma increases, which increases risk of myopathy, in rare cases - rhabdomyolysis with acute renal failure.
Because the atorvastatin is metabolized predominantly by isoenzyme CYP3A4 cytochrome P450, the simultaneous use of atorvastatin with inhibitor preparations or isoenzyme substrates 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 CYP3A4. Atorvastatin and its metabolites are substrates of the transport protein OATP1B1.
Inhibitors of transport protein OATP1B1 when combined, can increase bioavailability atorvastatin.
Inhibitors CYP3A4
Cyclosporin (substrate CYP3A4, inhibitor of the transporter OATP1B1). The combined use of atorvastatin 10 mg and cyclosporine at a dose of 5.2 mg / kg / day led to an increase in the concentration of atorvastatin in blood plasma by 7.7 times. If a joint application is necessary, the maximum daily dose of atorvastatin should not exceed 10 mg.
Erythromycin, clarithromycin. With simultaneous use of atorvastatin and erythromycin (500 mg 4 times / day) or clarithromycin (500 mg 2 times / day), there was a significant increase in the concentration of atorvastatin in the blood plasma. If necessary joint use with these drugs, the maximum daily dose of atorvastatin should not exceed 20 mg.
Inhibitors of proteases. Simultaneous use of atorvastatin with protease inhibitors, known as isoenzyme inhibitors CYP3A4, was accompanied by an increase concentrations of atorvastatin in blood plasma (when combined with erythromycin, an increase in Cmah atorvastatin by 40%).
HIV protease inhibitors. Against the backdrop of concomitant use with atorvastatin, a combination of HIV protease inhibitorsatorvastatin 40 mg and ritonavir + saquinavir 400 mg 2 times / day; atorvastatin 20 mg and lopinavir 400 mg + ritonavir 100 mg 2 times / day) there was a significant increase AUC atorvastatin. Simultaneous use of atorvastatin in a dose of 10 mg and nelfinavir mesylate 1250 mg 2 times a day was accompanied by an increase in the concentration of atorvastatin in blood plasma (an increase AUC by 74% and Cmah on 122%). If it is necessary to use together with these drugs, the maximum daily dose of atorvastatin should not exceed 20 mg.
Diltiazem. The combined use of atorvastatin in a dose of 40 mg with diltiazem in a dose of 240 mg resulted in an increase AUC atorvastatin by 50%. If necessary, a joint application with diltiazem atorvastatin should be taken at the lowest effective dose.
Verapamil, amiodarone. Joint application can lead to an increase concentrations of atorvastatin.
Cimetidine. Clinically significant interaction of atorvastatin with cimetidine was not detected.
Itraconazole. The combined use of atorvastatin in doses of 20 mg and 40 mg and itraconazole at a dose of 200 mg resulted in a 2.5-3-fold increase AUC. Atorvastatin, If necessary, combined with azole antifungal agents, the maximum daily dose of Atomax® should not exceed 20 mg.
Grapefruit juice contains components that inhibit CYP3A4. Excessive consumption of grapefruit juice (more than 1.2 l / day) can lead to a significant increase in the concentration of atorvastatin in the blood plasma.
Inductors CYP3A4
The use of atorvastatin in conjunction with isozyme inducing drugs CYP3A4 (eg, phenytoin, efavirenz, rifampicin, St. John's wort perforated) can lead to a decrease in the concentration of atorvastatin in blood plasma and inadequate efficacy. Due to the dual mechanism of interaction from rifampicin (inducer FROMYP3A4 and hepatocyte transport protein inhibitor OATP1B1), simultaneous use of atorvastatin and rifampicin is recommended,because delayed administration of atorvastatin after taking rifampicin leads to a significant decrease in the concentration of atorvastatin in the blood plasma.
Other concomitant therapy
Antipyrine (phenazone). Atorvastatin does not affect the pharmacokinetics of phenazone, so the interaction with other drugs metabolized by the same isoenzymes of cytochrome P450, not expected.
Antacids. Simultaneous reception of a suspension containing magnesium hydroxides and aluminum, led to a decrease in the concentration of atorvastatin in the blood plasma by about 35%, but the degree of decrease in the cholesterol-LDL content did not change.
Kolestipol. With the simultaneous use of colestipol, the concentration of atorvastatin in the blood plasma decreased by about 25%, but the lipid-lowering effect of the combination of these drugs was superior to that of each drug alone. Colestipol can weaken the absorption of atorvastatin, so between the intake of medications should be maintained interval of at least 2 hours.
Gemfibrozil. Concomitant use of gemfibrozil 600 mg 2 times / day was accompanied by an increase in the concentration of atorvastatin by 24%.
Digoxin. When re-ingesting digoxin in a dose of 0.25 mg and atorvastatin at a dose of 10 mg the equilibrium concentrations of digoxin in the blood plasma did not change; atorvastatin at a dose of 80 mg / day caused an increase in the concentration of digoxin by about 20%. Patients receiving digoxin in combination with atorvastatin in high doses, require appropriate monitoring.
Azithromycin. With the simultaneous use of atorvastatin at a dose of 10 mg / day and azithromycin at a dose of 500 mg once a day, the concentration of atorvastatin in the blood plasma did not change.
Oral contraceptives. When combined use of atorvastatin and oral contraceptive containing norethisterone and ethinyl estradiol, there was a significant increase AUC norethisterone and ethinylestradiol (approximately 30% and 20%, respectively). This effect must be taken into account when choosing an oral contraceptive for a woman receiving atorvastatin.
Hormone replacement therapy with estrogen. There is no evidence of a cynically significant interaction with the simultaneous administration of atorvastatin and hormone replacement therapy with estrogens.
Warfarin. When combined with atorvastatin in the first days of treatment, it is possible to increase the effect of warfarin on blood coagulation indices (reduction of prothrombin time). After 15 days of therapy, the prothrombin time returns to the initial, determined before the start of joint use of drugs.
Amlodipine. With the simultaneous use of atorvastatin in a dose of 80 mg and amlodipine at a dose of 10 mg, the pharmacokinetics of atorvastatin in the equilibrium state did not change. No obvious changes in blood pressure or heart rate were observed.
Hinapril. The combined use of quinapril 80 mg and atorvastatin 10 mg did not significantly alter the pharmacokinetic profile of atorvastatin.