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Drug Interactions between Alfenta and phenylbutazone

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

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Interactions between your drugs

Moderate

ALfentanil phenylbutazone

Applies to: Alfenta (alfentanil) and phenylbutazone

MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of alfentanil, which appears to be extensively metabolized by the isoenzyme. Clinical data are limited, however. In nine healthy male volunteers, intravenous administration of a single 20 mcg/kg dose of alfentanil with the potent CYP450 3A4 inducer rifampin increased alfentanil clearance by nearly 3-fold and decreased elimination half-life by 40% compared to controls. Another study also reported substantially increased clearance rates of alfentanil in seven patients receiving long-term therapy with inducer drugs compared to six patients not receiving those drugs (mean clearance 6.94 mL/min/kg vs. 3.47 mL/min/kg; half-life 50.6 hrs vs. 90.7 hrs).

MANAGEMENT: Patients who are currently receiving or have recently received drugs that induce CYP450 3A4 should be monitored for potentially decreased response to alfentanil, and the dosage adjusted as necessary.

References

  1. Kharasch ED, Thummel KE "Human alfentanil metabolism by cytochrome P450 3A3/4. An explanation for the interindividual variability in alfentanil clearance?" Anesth Analg 76 (1993): 1033-9
  2. Koehntop DE, Noormohamed SE, Fletcher CV "Effects of long-term drugs on alfentanil clearance in patients undergoing renal transplantation." Pharmacotherapy 14 (1994): 592-9
  3. Labroo RB, Thummel KE, Kunze KL, Podoll T, Trager WF, Kharasch ED "Catalytic role of cytochrome P4503A4 in multiple pathways of alfentanil metabolism." Drug Metab Dispos 23 (1995): 490-6
  4. Kharasch ED, Russell M, Mautz D, Thummel KE, Kunze KL, Bowdle A, Cox K "The role of cytochrome P450 3A4 in alfentanil clearance. Implications for interindividual variability in disposition and perioperative drug interactions." Anesthesiology 87 (1997): 36-50
View all 4 references

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Drug and food interactions

Moderate

ALfentanil food

Applies to: Alfenta (alfentanil)

GENERALLY AVOID: Ethanol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.

MANAGEMENT: Concomitant use of opioid analgesics with ethanol should be avoided.

References

  1. Linnoila M, Hakkinen S "Effects of diazepam and codeine, alone and in combination with alcohol, on simulated driving." Clin Pharmacol Ther 15 (1974): 368-73
  2. Sturner WQ, Garriott JC "Deaths involving propoxyphene: a study of 41 cases over a two-year period." JAMA 223 (1973): 1125-30
  3. Girre C, Hirschhorn M, Bertaux L, et al. "Enhancement of propoxyphene bioavailability by ethanol: relation to psychomotor and cognitive function in healthy volunteers." Eur J Clin Pharmacol 41 (1991): 147-52
  4. Levine B, Saady J, Fierro M, Valentour J "A hydromorphone and ethanol fatality." J Forensic Sci 29 (1984): 655-9
  5. Sellers EM, Hamilton CA, Kaplan HL, Degani NC, Foltz RL "Pharmacokinetic interaction of propoxyphene with ethanol." Br J Clin Pharmacol 19 (1985): 398-401
  6. Carson DJ "Fatal dextropropoxyphene poisoning in Northern Ireland. Review of 30 cases." Lancet 1 (1977): 894-7
  7. Rosser WW "The interaction of propoxyphene with other drugs." Can Med Assoc J 122 (1980): 149-50
  8. Edwards C, Gard PR, Handley SL, Hunter M, Whittington RM "Distalgesic and ethanol-impaired function." Lancet 2 (1982): 384
  9. Kiplinger GF, Sokol G, Rodda BE "Effect of combined alcohol and propoxyphene on human performance." Arch Int Pharmacodyn Ther 212 (1974): 175-80
View all 9 references

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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.

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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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