|
|
Coenzyme Q10 | |
|
Grapefruit or grapefruit juice Vitamin A* | |
|
Magnesium hydroxide Magnesium oxide Magnesium-containing antacids Niacin | |
| Side effect reduction/prevention |
None known |
| Supportive interaction |
None known |
| Reduced drug absorption/bioavailability |
None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Coenzyme Q10
In a double-blind trial, individuals with high cholesterol who were treated with lovastatin or pravastatin (drugs related to atorvastatin) for 18 weeks had a significant reduction in blood levels of
coenzyme Q10 (CoQ10).1 One study found that supplementation with 100 mg of CoQ10
prevented declines in CoQ10 levels when taken with
simvastatin (another HMG-CoA reductase inhibitor drug).2 Many doctors recommend
that people taking HMG-CoA reductase inhibitor drugs such as atorvastatin also supplement with
approximately 100 mg CoQ10 per day, although lower amounts, such as 10–30 mg per day,
might conceivably be effective in preventing the decline in CoQ10 levels.
Magnesium-containing antacids
A magnesium- and aluminium-containing antacid was reported
to interfere with atorvastatin absorption.3 People can avoid this interaction by
taking atorvastatin two hours before or after any aluminium/magnesium-containing antacids.
Some magnesium supplements such as magnesium hydroxide are also antacids.
Niacin
Niacin is the form of vitamin B3 used to lower
cholesterol. Ingestion of large amounts of niacin along with lovastatin (a drug closely related to atorvastatin) or with
atorvastatin itself may cause muscle disorders (myopathy) that can become serious
(rhabdomyolysis).4 5 Such problems appear to be uncommon when HMG-CoA
reductase inhibitors are combined with niacin.6 7 Moreover, concurrent
use of niacin with HMG-CoA reductase inhibitors has been reported to enhance the
cholesterol-lowering effect of the drugs.8 9 Individuals taking
atorvastatin should consult their physician before taking niacin.
Vitamin A
A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors
found blood vitamin A levels increased over two years of therapy.10 Until more is
known, people taking HMG-CoA reductase inhibitors, including atorvastatin, should have blood
levels of vitamin A monitored if they intend to supplement vitamin A.
Food
Atorvastatin is best absorbed when taken without food11 in the
morning.12 However, it has been reported to be equally well absorbed when taken
with or without food.13
Grapefruit or grapefruit
juice
Grapefruit contains substances that may inhibit the body’s ability to break down
atorvastatin; consuming grapefruit or grapefruit juice might therefore increase the potential
toxicity of the drug. There is one case report of a woman developing severe muscle damage from
simvastatin (a drug similar to atorvastatin) after she began eating one grapefruit per
day.14 Although there have been no reports of a grapefruit–atorvastatin
interaction, to be on the safe side, people taking atorvastatin should not eat grapefruit or
drink grapefruit juice.
1. Mortensen SA, Leth A, Agner E, Rohde M. Dose-related decrease of serum coenzyme Q10 during treatment with HMG-CoA reductase inhibitors. Mol Aspects Med 1997;18(suppl):S137–44.
2. Bargossi AM, Grossi G, Fiorella PL, et al. Exogenous CoQ10 supplementation prevents plasma ubiquinone reduction induced by HMG-CoA reductase inhibitors. Mol Aspects Med 1994;15(suppl):s187–93.
3. Threlkeld DS, ed. Diuretics and Cardiovasculars, Antihyperlipidemic Agents, HMG-CoA Reductase Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Sep 1998, 172a.
4. Garnett WR. Interactions with hydroxymethylglutaryl-coenzyme A reductase inhibitors. Am J Health Syst Pharm 1995;52:1639–45.
5. Yee HS, Fong NT. Atorvastatin in the treatment of primary hypercholesterolemia and mixed dyslipidemias. Ann Pharmacother 1998;32:1030–43.
6. Jacobson TA, Amorosa LF. Combination therapy with fluvastatin and niacin in hypercholesterolemia: a preliminary report on safety. Am J Cardiol 1994;73:25D–9D.
7. Jokubaitis LA. Fluvastatin in combination with other lipid-lowering agents. Br J Clin Pract Suppl 1996;77A:28–32.
8. Davignon J, Roederer G, Montigny M, et al. Comparative efficacy and safety of pravastatin, Nicotinic acid and the two combined in patients with hypercholesterolemia. Am J Cardiol 1994;73:339–45.
9. Jacobson TA, Jokubaitis LA, Amorosa LF. Fluvistatin and niacin in hypercholesterolemia: a preliminary report on gender differences in efficacy. Am J Med 1994;96(suppl 6A):64S–8S.
10. Muggeo M, Zenti MG, Travia D, et al. Serum retinol levels throughout 2 years of cholesterol-lowering therapy. Metabolism 1995;44:398–403.
11. Radulovic LL, Cilla DD, Posvar EL, et al. Effect of food on the bioavailability of atorvastatin, an HMG-CoA reductase inhibitor. J Clin Pharmacol 1995;35:990–4.
12. Cilla DD Jr, Gibson DM, Whitfield LR, Sedman AJ. Pharmacodynamic effects and pharmacokinetics of atorvastatin after administration to normocholesterolemic subjects in the morning and evening. J Clin Pharmacol 1996;36:604–9.
13. Radulovic LL, Cilla DD, Posvar EL, et al. Effect of food on the bioavailability of atorvastatin, an HMG-CoA reductase inhibitor. J Clin Pharmacol 1995;35:990–4.
14. Dreier JP, Endres M. Statin-associated rhabdomyolysis triggered by grapefruit consumption. Neurology 2004;62:670 [Letter].
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