Methylprednisolone elimination

Fost DA, Leung DY, Martin RJ, Brown EE, Szefler SJ, Spahn JD. Inhibition of methylprednisolone elimination in the presence of clarithromycin therapy. J Allergy Clin Immunol 1999 103(6) 1031-5. 

Some macrolides have a dose- and time-related effect on methylprednisolone elimination, resulting in a prolonged half-life and reduced clearance (157). These changes were considered advantageous (steroid sparing) in patients with asthma (158,159). However, a retrospective analysis of 3995 patients treated with azithromycin did not show any pharmacokinetic interaction in patients who were also taking methylprednisolone (127,128). 

LaForce CF, Szefler SJ, Miller MF, Ebling W, Brenner M. Inhibition of methylprednisolone elimination indie presence of erythromycin therapy. J Allergy CUnImmunol (1983) 72,34-9. 

Detailed pharmacokinetic studies were performed on transscleral iontophoresis of various drugs [38-40,42,75-78]. Each drug resulted in different patterns of distribution in the vitreous. Carboplatin distribution in the vitreous after iontophoretic delivery demonstrated heightened levels in a controlled manner from 1 to 6 h after treatment [39], Foscarnet iontophoresis demonstrated a very low elimination rate, thus therapeutic levels in the vitreous were maintained for up to 60 h [78]. Methylprednisolone obtained a relatively low peak concentration 2 h after treatment [38], and gentamicin showed a peak concentration 16 h after the transscleral iontophoresis [42]. 

A study in 14 healthy subjects found that itraconazole 400 mg for one day and then 200 mg daily for the next 3 days, increased the AUC of a single 48-mg dose of methylprednisolone by more than 2.5-fold." Other studies in healthy subjeets have found that itraeonazole decreases the clearance, and inereases the elimination half-life and AUC of both oral and intravenous methylprednisolone. Enhaneed adrenal suppression also occurred. ... 

---