Lipitor and Caffeine Interaction: What the Evidence Actually Shows

Does caffeine interact with atorvastatin?

The Lipitor label's interaction section is built around drugs and foods that change atorvastatin exposure, and caffeine is not among them [1].

What the label does describe is atorvastatin's own dependencies. It is a substrate of CYP3A4 and of the transporters OATP1B1/OATP1B3, P-glycoprotein and BCRP, and inhibitors of those pathways raise atorvastatin plasma levels and the risk of myopathy and rhabdomyolysis [1].

Caffeine is a different case. Its main human pathway is 3-N-demethylation to paraxanthine, catalysed by CYP1A2, and the FDA uses caffeine as a clinical index substrate for CYP1A2 [2][4]. A CYP3A4-catalysed 8-hydroxylation route exists, but it is not specific enough to be used as a marker of CYP3A4 activity [2].

What the Lipitor label does warn about

Atorvastatin exposure rises sharply with some common prescriptions. Clarithromycin 500 mg twice daily raised atorvastatin AUC 4.54-fold (measured with atorvastatin 80 mg), and itraconazole 200 mg daily raised it 3.32-fold; with either drug the label says not to exceed atorvastatin 20 mg daily [1]. Cyclosporine 5.2 mg/kg a day raised the AUC of atorvastatin 10 mg 8.69-fold, and the label says that combination is not recommended [1]. Gemfibrozil 600 mg twice daily raised the AUC of a single 40 mg atorvastatin dose 1.35-fold with no change in peak concentration, and the label also says not to combine it with Lipitor [1].

Grapefruit juice is the dietary entry on that list. A 240 mL glass daily raised the AUC of a single 40 mg atorvastatin dose 1.37-fold, and the label says to avoid large quantities, more than 1.2 liters daily [1]. Coffee, tea and caffeine appear in none of these tables [1].

Do coffee, tea and energy drinks differ?

The FDA says the body handles naturally occurring and added caffeine the same way, so the form matters less than the amount [3]. Per 12 fluid ounces, brewed coffee runs 113 to 247 mg, black tea 71 mg, green tea 37 mg, a caffeinated soft drink 23 to 83 mg and an energy drink 41 to 246 mg; 16-fluid-ounce energy drinks run 54 to 328 mg [3]. Decaf is not caffeine-free: typically 2 to 15 mg per 8-ounce cup [3].

The FDA also notes that people vary widely in sensitivity to caffeine and in how quickly they clear it [3].

What changes caffeine levels

Some medicines and habits can slow or speed caffeine clearance. The Lipitor label does not list caffeine among the drugs affected by atorvastatin [1].

• Fluvoxamine, a strong CYP1A2 inhibitor: in 8 volunteers given 200 mg caffeine, total clearance fell from 107 to 21 mL/min and half-life rose from 5 to 31 hours [5]. In a second study of 7 volunteers, clearance fell from 105 to 9.1 mL/min and half-life rose from 4.9 to 56 hours, with no measurable change in alertness, psychomotor performance or EEG effects after a single caffeine dose [6].
• Ciprofloxacin: the Cipro label says it is a CYP1A2 inhibitor and lists caffeine, with reduced clearance, higher levels and a longer half-life [7].
• Combined oral contraceptives: half-life 7.88 versus 5.37 hours and clearance 1.05 versus 1.75 mL/min/kg in pill users versus controls [8]; a second study found 10.7 versus 6.2 hours [9].
• Smoking: half-life 3.5 hours in 13 smokers versus 6.0 hours in 13 non-smokers [10], and stopping heavy smoking cut caffeine clearance by 36.1% [11].

On the other side, the Lipitor label describes what atorvastatin does to other drugs: it raised norethindrone AUC 1.28-fold and ethinyl estradiol AUC 1.19-fold, raised steady-state digoxin AUC 1.15-fold and peak 1.20-fold, and had no clinically significant effect on prothrombin time in patients on chronic warfarin [1]. Caffeine is not part of that list [1].

Does the time of day matter for the atorvastatin dose?

The label says to take Lipitor once daily at any time of day, with or without food [1]. Evening dosing produces about 30% lower peak and total exposure than morning dosing, and food lowers peak concentration about 25% and AUC about 9%, but LDL-C reduction is the same in each case [1].

What to watch for on atorvastatin

Myopathy and rhabdomyolysis are the label's main safety concern. Risk factors are age 65 or older, uncontrolled hypothyroidism, renal impairment, interacting drugs and higher doses, and the label says patients should promptly report unexplained muscle pain, tenderness or weakness, particularly with malaise or fever [1]. In 17 placebo-controlled trials (8,755 people on Lipitor, 7,311 on placebo), myalgia occurred in 3.5% versus 3.1% on placebo, and myalgia was the most common reason for stopping above placebo, at 0.7% [1]. In TNT, creatine kinase of 10 times the upper limit of normal or more occurred in 0.3% of people on 80 mg versus 0.1% on 10 mg [1]. Caffeine is not one of the listed risk factors [1].