<p>Drug interaction with atorvastatin: The risk of myopathy during treatment with drugs of this class is increased with concurrent administration of cyclosporine, fibric acid derivatives, niacin (nicotinic acid), erythromycin, azole antifungals. When atorvastatin and antacid suspension containing magnesium and aluminum hydroxide were co administered, plasma concentrations of atorvastatin decreased approximately 35%. However, LDL-C reduction was not altered. Plasma concentrations of atorvastatin decreased approximately 25% when colestipol and atorvastatin were co administered. However, LDL-C reduction was greater when atorvastatin and colestipol were co-administered than when either drug was given alone. When multiple doses of atorvastatin and digoxin were co-administered, steady state plasma digoxin concentrations increased by approximately 20%. Patients taking digoxin should be monitored appropriately. In healthy individuals, plasma concentrations of atorvastatin increased approximately 40% with co- administration of atorvastatin and erythromycin. Co- administration of atorvastatin and an oral contraceptive increased AUC values for norethindrone and ethinylestradiol by approximately 30% and 20%. These increases should be considered when selecting an oral contraceptive for a woman taking atorvastatin.<br />
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Drug interaction with amlodipine: Amlodipine may potentiate the effect of other antihypertensive (e.g.Beta-blockers, ACE inhibitors, Alpha-1-blockers and Diuretics). In clinical interaction studies, Amlodipine did not affect the pharmacokinetics of Atorvastatin, Digoxin, Warfarin or Cyclosporine.</p>