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Drug Interactions between Cerebyx and Rayos

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

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Interactions between your drugs

Moderate

predniSONE fosphenytoin

Applies to: Rayos (prednisone) and Cerebyx (fosphenytoin)

MONITOR: Phenytoin and other hydantoins may induce the CYP450 3A4 hepatic metabolism of corticosteroids and increase their clearance and decrease their half-lives, possibly reducing their therapeutic efficacy. In addition, results of the dexamethasone adrenal suppression test may be unreliable in patients concurrently taking phenytoin. Hydrocortisone appears to be affected to a lesser extent than other corticosteroids. Some corticosteroids have also been reported to cause increases or decreases in serum phenytoin levels; however, data have been inconsistent.

MANAGEMENT: Patients should be closely monitored for clinical and laboratory evidence of reduced corticosteroid effects and changes in phenytoin concentrations during concomitant therapy. Some patients may require increased corticosteroid dosages.

References

  1. Frey BM, Frey FJ "Phenytoin modulates the pharmacokinetics of prednisolone and the pharmacodynamics of prednisolone as assessed by the inhibition of the mixed lymphocyte reaction in humans." Eur J Clin Invest 14 (1984): 1-6
  2. Wong DD, Longenecker RG, Liepman M, Baker S, LaVergne M "Phenytoin-dexamethasone: a possible drug-drug interaction." JAMA 254 (1985): 2062-3
  3. Lackner TE "Interaction of dexamethasone with phenytoin." Pharmacotherapy 11 (1991): 344-7
  4. Lawson LA, Blouin RA, Smith RB, Rapp RP, Young AB "Phenytoin-dexamethasone interaction: a previously unreported observation." Surg Neurol 16 (1981): 23-4
  5. Haque N, Thrasher K, Werk EE, Jr Knowles HC, Jr Sholiton LJ "Studies on dexamethasone metabolism in man: effect of diphenylhydantoin." J Clin Endocrinol Metab 34 (1972): 44-50
  6. Stjernholm MR, Katz FH "Effects of diphenylhydantoin, phenobarbital, and diazepam on the metabolism of methylprednisolone and its sodium succinate." J Clin Endocrinol Metab 41 (1975): 887-93
View all 6 references

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Drug and food interactions

No alcohol/food interactions were found. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.

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

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

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