Interactions : אינטראקציות

4.5   Interaction with other medicinal products and other forms of interaction
Aciclovir is eliminated primarily unchanged in the urine via active renal tubular secretion. Any drugs administered concurrently that compete with this mechanism may increase aciclovir plasma concentrations. Probenecid and cimetidine increase the AUC of aciclovir by this mechanism and reduce aciclovir renal clearance. However no dosage adjustment is necessary because of the wide therapeutic index of aciclovir.
In patients receiving intravenous Zovirax caution is required during concurrent administration with drugs which compete with aciclovir for elimination, because of the potential for increased plasma concentrations of one or both drugs or their metabolites.
Increases in plasma AUCs of aciclovir and of the inactive metabolite of mycophenolate mofetil, an immunosuppressant agent used in transplant patients, have been shown when the drugs are coadministered.
If lithium is administered concurrently with high dose aciclovir IV, the lithium serum concentration should be closely monitored because of the risk of lithium toxicity.
Care is also required (with monitoring for changes in renal function) if administering intravenous Zovirax with drugs which affect other aspects of renal physiology (e.g.
cyclosporin, tacrolimus).
An experimental study on five male subjects indicates that concomitant therapy with aciclovir increases AUC of totally administered theophylline with approximately 50%.
It is recommended to measure plasma concentrations during concomitant therapy with aciclovir.