The risk of myopathy during treatment with HMG-CoA reductase inhibitors increases with simultaneous use with cyclosporine, erythromycin, clarithromycin, immunosuppressive, antifungal agents (azole derivatives) due to a possible increase concentration of atorvastatin in serum.
When used simultaneously with inhibitors of HIV proteases - indinavir, ritonavir - the risk of myopathy increases.
A similar interaction is possible with simultaneous use of atorvastatin with fibrates and nicotine acid at lipid-lowering doses (more than 1 g / day).
Inhibitor inhibitors CYP3A4
Since atorvastatin is metabolized by isoenzyme CYP3A4, co-administration Tulip® with inhibitors of this isoenzyme may lead to an increase in the concentration of atorvastatin in the blood plasma. The degree of interaction and the effect of increasing the concentration of atorvastatin are determined variability of exposure to isoenzyme CYP3A4.
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, the use of atorvastatin in a dose of 10 mg and cyclosporine at a dose of 5.2 mg / kg / day leads to an increase the concentration of atorvastatin in blood plasma is 7.7 times.
Erythromycin / clarithromycin
With simultaneous application Atorvastatin 10 mg and erythromycin (500 mg 4 times daily) or clarithromycin (500 mg twice daily) that inhibit the cytochrome isoenzyme CYP3A4, there is an increase concentrations of atorvastatin in the blood plasma (by 40% - with erythromycin and 56% - with clarithromycin).
Inhibitors of proteases
Simultaneous application Atorvastatin with protease inhibitors, known as inhibitors of the cytochrome isoenzyme CYP3A4, is accompanied by an increase concentration of atorvastatin in blood plasma (with simultaneous use with erythromycin - FROMmOh atorvastatin is increased by 40%).
Diltiazem
Joint application Atorvastatin 40 mg with diltiazem in a dose of 240 mg leads to an increase in the concentration of atorvastatin in the blood plasma.
Cimetidine
Clinically significant the interaction of atorvastatin with cimetidine was not revealed.
Itraconazole
Simultaneous application Atorvastatin at doses of 20 mg to 40 mg and itraconazole at a dose of 200 mg conducts a 3-fold increase in the value AUC atorvastatin.
Grapefruit juice
Because grapefruit juice contains one or more components that inhibit the isoenzyme CYP3A4, its excessive use (more than 1.2 liters per day for 5 days) can cause an increase in concentration atorvastatin in the blood plasma.
Inductors of isoenzyme CYP3A4
A joint application of atorvastatin with isoenzyme inducers CYP3A4 (eg, efavirenz or rifampicin) can lead to a decrease in the concentration of atorvastatin in the blood plasma. Due to the dual mechanism of interaction with rifampicin (inductor isoenzyme CYP3A4 and an inhibitor of the hepatocyte transport protein OATP1B1), simultaneous use is not recommended atorvastatin and rifampicin, since delayed administration of atorvastatin after rifampicin administration leads to a significant reduction concentrations of atorvastatin in blood plasma.
Antacids
With simultaneous administration of atorvastatin and a suspension containing magnesium and aluminum hydroxides, the concentration Atorvastatin in plasma is reduced by about 35%, but the degree of decrease in concentration LDL cholesterol does not change.
Fenazone
Atorvastatin does not affect the pharmacokinetics of phenazone, therefore interaction with other drugs metabolized by the same isoenzymes is not expected.
Kolestypol
Lipid-lowering effect The combination with colestipol exceeds that for each drug alone, despite a decrease in concentration atorvastatin by 25% with its simultaneous application with colestipol.
Fusidic acid
There have been no studies on the interaction of atorvastatin and fusidic acid. As in the case of other statins, in post-marketing research joint application atorvastatin and fusidic acid reported side effects on muscles, including rhabdomyolysis. The mechanism of interaction is unknown. Such patients require careful follow-up and, possibly, a temporary discontinuation of atorvastatin.
Colchicine
Although no studies have been conducted on the interaction of atorvastatin and colchicine, cases have been reported myopathies in a joint use with colchicine, and with the simultaneous administration of atorvastatin and colchicine, caution should be exercised.
Digoxin
With the repeated use of digoxin and atorvastatin at a dose of 10 mg, the equilibrium concentrations of digoxin in the blood plasma do not change. However, when using digoxin in combination with atorvastatin in a dose of 80 mg / day. the concentration of digoxin in the blood plasma increases by approximately 20%. Patients receiving digoxin in combination with atorvastatin, control of digoxin concentration in blood plasma is required.
Azithromycin
With the simultaneous use of atorvastatin in a dose of 10 mg 1 time / day and azithromycin at a dose of 500 mg 1 time / day, the concentration of atorvastatin in the blood plasma does not change.
Oral contraceptives
With simultaneous application atorvastatin and an oral contraceptive containing norethisterone and ethinyl estradiol, a significant rise AUC norethisterone and ethinyl estradiol by approximately 30% and 20%, respectively, which should be considered when choosing an oral contraceptive.
Terfenadine
Atorvastatin with simultaneous application with terfenadine does not have a clinically significant effect on the pharmacokinetics of terfenadine.
Warfarin
Patients who take long-term warfarin, atorvastatin in a dose of 80 mg per day somewhat shortens prothrombin time in the first days of joint application. This effect disappears after 15 days of simultaneous application of these drugs. Although the cases of clinically significant changes in anticoagulant effect was reported very rarely, prothrombin time in patients taking coumarin anticoagulants before and often enough at the beginning of treatment with atorvastatin to ensure no significant changes in prothrombin time. As soon as a stable prothrombin time, it can be tested at intervals common to patients taking coumarin anticoagulants. When changing the dose or discontinuing treatment, these measures should be repeated. There was no association between the use of atorvastatin and bleeding or a change in prothrombin time in patients not taking anticoagulants.
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 does not change.
Other lipid-lowering drugs
With simultaneous use of atorvastatin with other lipid-lowering drugs (for example, ezetimibe, gemfibrozil, a derivative of fibroic acid) in lipid-lowering doses increased risk of developing rhabdomyolysis.
Other concomitant therapy
With the simultaneous use of atorvastatin with antihypertensive agents and estrogens (as a substitute therapy) clinically significant no interaction was found.