The risk of myopathy during treatment with other drugs of this class increases with simultaneous use of cyclosporine, fibrates, antibiotics of the macrolide group, including erythromycin, antifungal agents related to azoles, HIV protease inhibitors and nicotinic acid in lipid lowering doses (more than 1 g per day ). The combined use of these drugs can also lead to the development of rhabdomyolysis and renal insufficiency caused by myoglobinuria. Care should be taken to evaluate the expected benefits of using a combination of these drugs and the possible adverse effects on the patient.
With the simultaneous use of drugs that increase the concentration of atorvastatin in blood plasma, the minimum initial dose of the latter should be taken. During the combined use of cyclosporine,clarithromycin or itraconazole is recommended to take a minimum dose of atorvastatin and establish a thorough monitoring of this group of patients.
Inhibitors of cytochrome P4503A4
Atorvastatin is metabolized by cytochrome P4503A4. Interactions may occur with the simultaneous use of atorvastatin and cytochrome P4503A4 inhibitors (such as ciclosporin; antibiotics of the macrolide group, including erythromycin; nefazodone; antifungal agents related to azoles, including itraconazole and HIV protease inhibitors). Care is needed during the simultaneous use of atorvastatin and drugs of this group, as this may cause an increase in the concentration of atorvastatin in the blood plasma.
Inhibitors of transport protein OATP1B1
Atorvastatin and its metabolites are a substrate of OATP1B1 transport proteins. The combined use of atorvastatin 10 mg and cyclosporine 5.2 mg / kg / day leads to an increase in the concentration of atorvastatin in blood plasma by 7.7 times. If you need a joint application with cyclosporine, the dose of Atorvastatin should not exceed 10 mg.
Erythromycin, clarithromycin
At simultaneous the use of atorvastatin 80 mg once a day and erythromycin (500 mg 4 times / day), the total activity of atorvastatin is increased by 33%. With the simultaneous use of atorvastatin at a dose of 10 mg per day and clarithromycin (500 mg 2 times / day), there was an increase in the concentration of atorvastatin in the blood plasma by 3.4 times. With the simultaneous administration of clarithromycin with atorvastatin, a minimum dose of atorvastatin is recommended. At a dose above 40 mg, careful monitoring of the patient in a hospital setting is recommended.
Itraconazole
The combined use of atorvastatin 40 mg and itraconazole 200 mg per day leads to an increase in the concentration of atorvastatin in blood plasma in 2.5-3.3 times. If the use of these two drugs is necessary simultaneously, the maintenance dose of atorvastatin should not exceed 40 mg per day. When taking a daily dose of atorvastatin 80 mg, if itraconazole is started, it should be reduced. When, when dose reduction is not possible, atorvastatin (for short courses of antifungal therapy) can be temporarily discontinued.
Inhibitors of proteases
The combined use of atorvastatin and protease inhibitors that inhibit cytochrome P450 AP4 results in an increase in the concentration of atorvastatin in blood plasma by a factor of two.
It is necessary to monitor the concentration of lipids in the blood plasma in order to determine the lowest effective dose of atorvastatin.
Diltiazem
Simultaneous use of atorvastatin in a dose of 40 mg and diltiazem 240 mg increases the concentration of atorvastatin in blood plasma by 51%. After the beginning of diltiazem application and after titration of the dose, careful monitoring of the patient in a hospital environment is required.
Grapefruit juice
Grapefruit juice contains one or more inhibitors of cytochrome P450 3A4, its administration can cause an increase in the concentration in the blood plasma of drugs metabolized by cytochrome P450 ZA4. After consuming 1 cup of grapefruit juice (240 ml) AUC Atorvastatin increases by 37% and AUC of the active orthohydroxy metabolite is reduced by 20.4%. A large amount of grapefruit juice (more than 1.2 liters per day for 5 days) causes an increase AUC atorvastatin 2.5 times and AUC atorvastatin and its metabolites in 1,3 times. It is not recommended to drink grapefruit juice in large quantities with atorvastatin therapy.
Inductors of cytochrome P450 ZA4
Simultaneous use of atorvastatin and cytochrome P450 inductors ZA4 (for example, efavirenz, rifampicin or herbal preparations based on St. John's Wort perforated) can lead to a decrease in the concentration of atorvastatin in the blood plasma. Because of the double mechanism of action of rifampicin (induction of cytochrome P450 and the blocking of transport protein OATP1B1 in hepatocytes), its simultaneous use with atorvastatin is recommended, since delayed administration of atorvastatin after taking rifampicin results in a significant decrease in the concentration of atorvastatin in the blood plasma.
Fusidic acid
Studies of the interaction of atorvastatin and fusidic acid have not been conducted. With the joint intake of drugs from the group of inhibitors of HMG-CoA reductase (statins) and fusidic acid, there have been reports of the development of adverse reactions from the muscular system, including rhabdomyolysis. The mechanism of this interaction is not known. It should be carefully monitored by patients taking both atorvastatin and fuzidovuyu, including may require a temporary discontinuation of atorvastatin.
Joint use of other drugs
Digoxin
With the repeated use 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 at a dose of 80 mg per day, the digoxin concentration increased by about 20%. This interaction is due to the inhibition of P-glycoprotein (transport membrane protein). Careful monitoring of patients receiving digoxin in combination with atorvastatin.
Oral contraceptives
With simultaneous, use of atorvastatin and oral contraceptives, containing norethindrone and ethinyl estradiol, there was a significant increase AUC norethindrone and ethinyl estradiol by about 30% and 20%, respectively. This effect should be considered when choosing an oral contraceptive for a woman receiving atorvastatin.
Kolestypol
With the simultaneous use of colestipol, concentrations of atorvastatin and its active metabolites in blood plasma decreased by approximately 25%. but The hypolipidemic effect of the combination of atorvastatin and colestipol was superior to that of each drug alone.
Antacids
When combined with atorvastatin and a suspension containing magnesium hydroxide and aluminum hydroxide, the concentrations of atorvastatin in the blood plasma were reduced by approximately 35%, however, the extent, cholesterol / LDL cholesterol reduction This has not changed.
Clinically significant interaction of atorvastatin with warfarin not detected.
Phenazone and cimetidine
When studying the interaction of atorvastatin with warfarin and cimetidine, no clinically significant interaction was found.
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 did not change in the equilibrium state.
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 once a day, the concentration of atorvastatin in the blood plasma did not change.
Terfenadine
Atorvastatin with simultaneous application with terfenadine did not have a clinically significant effect on its pharmacokinetics.