Steroid-specific and anticonvulsant interaction aspects of troleandomycin-steroid therapy

J Allergy Clin Immunol. 1982 May;69(5):455-60. doi: 10.1016/0091-6749(82)90121-x.


Troleandomycin (TAO) is a macrolide antibiotic that has an apparent "steroid-sparing" effect when used in the treatment of severe steroid-dependent asthmatic patients. Recent observations demonstrated the effect of TAO on inhibiting methylprednisolone elimination, possibly contributing to its beneficial effects. Prednisolone and methylprednisolone disposition were studied before and 1 wk after initiation of TAO therapy in three patients. Methylprednisolone elimination was characteristically impaired in the presence of TAO therapy; however, there was no apparent effect on prednisolone elimination. Methylprednisolone elimination was also evaluated before and after initiation of TAO therapy in three patients receiving concomitant anticonvulsant therapy with phenobarbital-1, phenytoin-2. Methylprednisolone clearance before TAO was at least 4 times faster than normal and was probably related to enzyme induction by the anticonvulsant medication. Methylprednisolone clearance was subsequently reduced by approximately 70% in the presence of TAO therapy. The effect of TAO on corticosteroid disposition is steroid-specific and TAO can diminish the effect of certain drugs on the induction of corticosteroid metabolism.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Asthma / drug therapy
  • Asthma / metabolism
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Humans
  • Methylprednisolone / metabolism*
  • Methylprednisolone / therapeutic use
  • Phenobarbital / pharmacology
  • Phenytoin / pharmacology
  • Prednisolone / metabolism*
  • Prednisolone / therapeutic use
  • Troleandomycin / pharmacology*
  • Troleandomycin / therapeutic use


  • Phenytoin
  • Prednisolone
  • Troleandomycin
  • Methylprednisolone
  • Phenobarbital