atorvastatin : Complexes, Storage & Clinical Research on Healthline.com

Inhibitors of CYP3A4: Potential pharmacokinetic interaction (variable increases in plasma atorvastatin concentrations); increased risk of myopathy. Carefully monitor patients for manifestations of unexplained muscle pain, tenderness, or weakness, particularly following initiation of atorvastatin therapy or an increase in dosage of either drug. (See Specific Drugs under Interactions.)

Inducers of CYP3A4: Potential pharmacokinetic interaction (variable reductions in plasma atorvastatin concentrations). (See Specific Drugs under Interactions.)

Specific Drugs

Drug	Interaction	Comments
Amlodipine	Modest increase in atorvastatin exposure	Not clinically relevant
Antacids	Decreased plasma atorvastatin concentrations
Anticoagulants, oral (e.g., warfarin)	Pharmacologic interaction (e.g., increased PT) unlikely
Azole antifungals	Itraconazole: 2.5 to threefold increase in atorvastatin AUC Increased risk of myopathy	Consider using lower initial and maintenance dosages of atorvastatin
Bile acid sequestrants	Decreased plasma atorvastatin concentrations	Administer statins ≥1 hour before or at least 2–4 hours after the resin
Cyclosporine	8.7-fold increase in atorvastatin AUC; increased risk of myopathy and/or rhabdomyolysis	Carefully monitor patients for manifestations of unexplained muscle pain, tenderness, or weakness, particularly following initiation of atorvastatin therapy or an increase in dosage Atorvastatin dosage should not exceed 10 mg daily
Digoxin	Increased plasma digoxin concentrations	Monitor appropriately
Diltiazem	Increased plasma atorvastatin concentrations
Efavirenz	Possible variable reductions in plasma atorvastatin concentrations
Fibric acid derivatives	Increased risk of myopathy Fenofibrate: Decreased or increased AUC of atorvastatin reported	Concomitant use generally should be avoided; if used concomitantly, initiate atorvastatin at low or moderate dosages and consider using lower maintenance dosages of atorvastatin
Grapefruit juice (particularly >1.2 L daily)	Increased bioavailability of atorvastatin
HIV protease inhibitors (combination of ritonavir plus saquinavir, combination of lopinavir plus ritonavir)	Combination of ritonavir plus saquinavir: Threefold increase in atorvastatin AUC and increased risk of myopathy Combination of lopinavir plus ritonavir: 5.9-fold increase in atorvastatin AUC and increased risk of myopathy	Carefully monitor patients for manifestations of unexplained muscle pain, tenderness, or weakness, particularly following initiation of atorvastatin therapy or an increase in dosage of either drug Consider using lower initial and maintenance dosages of atorvastatin In patients receiving the combination of ritonavir and saquinavir, or the combination of lopinavir and ritonavir, use of atorvastatin dosages >20 mg daily requires appropriate clinical assessment to ensure that the lowest effective dosage is employed
Macrolide antibiotics (i.e., clarithromycin, erythromycin)	Clarithromycin: 4.4-fold increase in atorvastatin AUC and increased risk of myopathy Erythromycin: Increased plasma atorvastatin concentrations and increased risk of myopathy	Carefully monitor patients for manifestations of unexplained muscle pain, tenderness, or weakness, particularly following initiation of atorvastatin therapy and an increase in dosage of either drug Consider using lower initial and maintenance dosages of atorvastatin In patients receiving clarithromycin, use of atorvastatin dosages >20 mg daily requires appropriate clinical assessment to ensure that the lowest effective dosage is employed
Niacin (antilipemic dosages)	Increased risk of myopathy	Use low dosages of niacin and carefully monitor patients for manifestations of unexplained muscle pain, tenderness, or weakness, particularly following initiation of atorvastatin therapy or an increase in dosage of either drug Consider using lower initial and maintenance dosages of atorvastatin
Oral contraceptives	Increased bioavailability of norethindrone and ethinyl estradiol	Caution when selecting an oral contraceptive
Rifampin	Possible variable reductions in plasma atorvastatin concentrations	Administer simultaneously, because delayed administration of atorvastatin following administration of rifampin associated with substantial reductions in plasma atorvastatin concentrations

Lipitor
PD 155 / 10 10 mg	PD 157 / 40 40 mg	PD 158 / 80 80 mg	PD 156 / 20 20 mg

Drug Notebook

Generic Name: atorvastatin

Drug Interactions

Drugs Affecting Hepatic Microsomal Enzymes

Specific Drugs