Skip to main content

Drug Interactions between Sustiva and Zagam

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

Edit list (add/remove drugs)

Interactions between your drugs

Major

sparfloxacin efavirenz

Applies to: Zagam (sparfloxacin) and Sustiva (efavirenz)

CONTRAINDICATED: Sparfloxacin may cause dose-related prolongation of the QT interval in some patients. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. Torsade de pointes has been reported in a few patients receiving sparfloxacin alone and with antiarrhythmic agents like amiodarone and disopyramide.

MANAGEMENT: Coadministration of sparfloxacin with other drugs that can prolong the QT interval is considered contraindicated.

References

  1. Thomas M, Maconochie JG, Fletcher E (1996) "The dilemma of the prolonged QT interval in early drug studies." Br J Clin Pharmacol, 41, p. 77-81
  2. Jaillon P, Morganroth J, Brumpt I, Talbot G (1996) "Overview of electrocardiographic and cardiovascular safety data for sparfloxacin. Sparfloxacin Safety Group." J Antimicrob Chemother, 37(suppl a), p. 161-7
  3. Zix JA, GeerdesFenge HF, Rau M, Vockler J, Borner K, Koeppe P, Lode H (1997) "Pharmacokinetics of sparfloxacin and interaction with cisapride and sucralfate." Antimicrob Agents Chemother, 41, p. 1668-72
  4. (2001) "Product Information. Zagam (sparfloxacin)." Rhone Poulenc Rorer
  5. Demolis JL, Charransol A, Funck-Brentano C, Jaillon P (1996) "Effects of a single oral dose of sparfloxacin on ventricular repolarization in healthy volunteers." Br J Clin Pharmacol, 41, p. 499-503
  6. Dupont H, Timsit JF, Souweine B, Gachot B, Wolff M, Regnier B (1996) "Torsades de pointe probably related to sparfloxacin." Eur J Clin Microbiol Infect Dis, 15, p. 350-1
  7. Lipsky BA, Dorr MB, Magner DJ, Talbot GH (1999) "Safety profile of sparfloxacin, a new fluoroquinolone antibiotic." Clin Ther, 21, p. 148-59
  8. Owens RC (2001) "Risk assessment for antimicrobial agent-induced QTc interval prolongation and torsades de pointes." Pharmacotherapy, 21, p. 301-19
  9. Iannini PB, Doddamani S, Byazrova E, Curciumaru I, Kramer H (2001) "Risk of torsades de pointes with non-cardiac drugs." BMJ, 322, p. 46-7
  10. Ball P (2000) "Quinolone-induced QT interval prolongation: a not-so-unexpected class effect." J Antimicrob Chemother, 45, p. 557-9
  11. Kang J, Wang L, Chen XL, Triggle DJ, Rampe D (2001) "Interactions of a series of fluoroquinolone antibacterial drugs with the human cardiac K+ channel HERG." Mol Pharmacol, 59, p. 122-6
  12. Oliphant CM, Green GM (2002) "Quinolones: a comprehensive review." Am Fam Physician, 65, p. 455-64
  13. Owens RC Jr, Ambrose PG (2002) "Torsades de pointes associated with fluoroquinolones." Pharmacotherapy, 22, 663-8; discussion 668-72
  14. Iannini PB (2002) "Cardiotoxicity of macrolides, ketolides and fluoroquinolones that prolong the QTc interval." Expert Opin Drug Saf, 1, p. 121-8
  15. Owens RC (2004) "QT Prolongation with Antimicrobial Agents : Understanding the Significance." Drugs, 64, p. 1091-124
  16. Katritsis D, Camm AJ (2003) "Quinolones: cardioprotective or cardiotoxic." Pacing Clin Electrophysiol, 26, p. 2317-20
  17. Stahlmann R (2002) "Clinical toxicological aspects of fluoroquinolones." Toxicol Lett, 127, p. 269-77
  18. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  19. Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
  20. Falagas ME, Rafailidis PI, Rosmarakis ES (2007) "Arrhythmias associated with fluoroquinolone therapy." Int J Antimicrob Agents, 29, p. 374-9
  21. Cerner Multum, Inc. "Australian Product Information."
View all 21 references

Switch to consumer interaction data

Drug and food interactions

Moderate

efavirenz food

Applies to: Sustiva (efavirenz)

ADJUST DOSING INTERVAL: Administration with food increases the plasma concentrations of efavirenz and may increase the frequency of adverse reactions. According to the product labeling, administration of efavirenz capsules (600 mg single dose) with a high-fat/high-caloric meal (894 kcal, 54 g fat, 54% calories from fat) or a reduced-fat/normal-caloric meal (440 kcal, 2 g fat, 4% calories from fat) was associated with mean increases of 39% and 51% in efavirenz peak plasma concentration (Cmax) and 22% and 17% in systemic exposure (AUC), respectively, compared to administration under fasted conditions. For efavirenz tablets, administration of a single 600 mg dose with a high-fat/high-caloric meal (approximately 1000 kcal, 500-600 kcal from fat) resulted in a 79% increase in mean Cmax and a 28% increase in mean AUC of efavirenz relative to administration under fasted conditions.

MANAGEMENT: Efavirenz should be taken on an empty stomach, preferably at bedtime. Dosing at bedtime may improve the tolerability of nervous system symptoms such as dizziness, insomnia, impaired concentration, somnolence, abnormal dreams and hallucinations, although they often resolve on their own after the first 2 to 4 weeks of therapy . Patients should be advised of the potential for additive central nervous system effects when efavirenz is used concomitantly with alcohol or psychoactive drugs, and to avoid driving or operating hazardous machinery until they know how the medication affects them.

References

  1. (2001) "Product Information. Sustiva (efavirenz)." DuPont Pharmaceuticals

Switch to consumer interaction data

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

Report options

Loading...
QR code containing a link to this page

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

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer