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Drug Interactions between eszopiclone and fosamprenavir

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Major

fosamprenavir eszopiclone

Applies to: fosamprenavir and eszopiclone

ADJUST DOSE: Coadministration with potent inhibitors of CYP450 3A4 may increase the plasma concentrations of both zopiclone and its pharmacologically active S(-) enantiomer, eszopiclone. Zopiclone has been shown in vitro to be metabolized by CYP450 3A4 and CYP450 2C8, while eszopiclone is primarily metabolized by CYP450 3A4 and 2E1 via demethylation and oxidation. In 18 healthy subjects, administration of a single 3 mg dose of eszopiclone with the potent CYP450 3A4 inhibitor ketoconazole (400 mg daily for 5 days) increased eszopiclone half-life, peak plasma concentration (Cmax) and systemic exposure (AUC) by 1.3-, 1.4- and 2.2-fold, respectively. In 10 healthy young subjects, itraconazole 200 mg daily given for 4 days increased the Cmax and AUC of a single 7.5 mg dose of zopiclone by 29% and 73%, respectively, and prolonged its half-life by 40%. The pharmacokinetics of eszopiclone were not reported in this study. A case report describes an 86-year-old woman who experienced morning drowsiness during coadministration of zopiclone and nefazodone, a known potent CYP450 3A4 inhibitor. Zopiclone plasma concentrations were measured both during and after withdrawal of nefazodone therapy. Following discontinuation of nefazodone due to lack of therapeutic effect, the plasma concentration of S(-) zopiclone decreased from 107 to 16.9 ng/mL, and that of R(+) zopiclone decreased from 20.6 to 1.45 ng/mL.

MANAGEMENT: Due to increased risk of next-day psychomotor impairment, the dosages of eszopiclone and zopiclone should be reduced when used with potent CYP450 3A4 inhibitors. The manufacturers recommend that total dose of eszopiclone not exceed 2 mg. An initial dose of 3.75 mg is recommended for zopiclone, which may be increased up to 5 mg if clinically indicated. Patients should be advised to avoid driving or operating hazardous machinery until they know how these medications affect them, preferably at least 12 hours after administration of the hypnotic.

References

  1. Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57
  2. Becquemont L, Mouajjah S, Escaffre O, Beaune P, Funck-Bretano C, Jaillon P (1999) "Cytochrome P-450 3A4 and 2C8 are involved in zopiclone metabolism." Drug Metab Dispos, 27, p. 1068-73
  3. Alderman CP, Gebauer MG, Gilbert AL, Condon JT (2001) "Possible interaction of zopiclone and nefazodone." Ann Pharmacother, 35, p. 1378-80
  4. (2004) "Product Information. Lunesta (eszopiclone)." Sepracor Inc
  5. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  6. Cerner Multum, Inc. "Australian Product Information."
  7. (2014) "Product Information. Imovane (zopiclone)." Rhone-Poulenc Rorer Canada Inc
View all 7 references

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Drug and food interactions

Moderate

fosamprenavir food

Applies to: fosamprenavir

ADJUST DOSING INTERVAL: Food may reduce the systemic bioavailability of amprenavir from fosamprenavir oral suspension. The mechanism of interaction has not been described. According to the product labeling, administration of fosamprenavir oral suspension (1400 mg single dose) with a high-fat meal (967 kcal, 67 g fat, 33 g protein, 58 g carbohydrate) reduced amprenavir peak plasma concentration (Cmax) by 46% and systemic exposure (AUC) by 28% compared to administration in a fasted state. The time to reach peak plasma level (Tmax) was delayed by 0.72 hours. In contrast, the same high-fat meal did not affect the pharmacokinetics of amprenavir from fosamprenavir tablets.

MANAGEMENT: Fosamprenavir suspension should be administered on an empty stomach in adults, but with food in pediatric patients to aid palatability and compliance. If emesis occurs within 30 minutes after dosing the suspension, the dose should be repeated. Fosamprenavir tablets may be taken with or without food.

References

  1. (2003) "Product Information. Lexiva (fosamprenavir)." GlaxoSmithKline

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Moderate

eszopiclone food

Applies to: eszopiclone

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of zopiclone and eszopiclone. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

ADJUST DOSING INTERVAL: Administration of eszopiclone (the S-enantiomer of zopiclone) with or immediately after a high-fat/heavy meal may delay the onset of hypnotic effects. In healthy adults, administration of a 3 mg dose of eszopiclone after a high-fat meal decreased the mean peak plasma drug concentration (Cmax) by 21% and delayed the time to reach peak plasma drug concentration (Tmax) by approximately 1 hour. Theoretically, this interaction should also affect racemic zopiclone.

MANAGEMENT: Patients receiving zopiclone or eszopiclone should be advised to avoid consumption of alcohol. For faster sleep onset, eszopiclone and zopiclone should not be administered with or immediately after a high-fat/heavy meal.

References

  1. (2004) "Product Information. Lunesta (eszopiclone)." Sepracor Inc
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

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