Adverse Event: Drug interaction leading to low exposure of mTor inhibitors and their ineffectiveness.
The Patient: A 24-year-old male patient, known to have tuberous sclerosis complex since birth, developed renal epithelioid angiomyolipomas with hepatic metastasis. Everolimus treatment failed after 8 months of administration, this lead to a switch to temsirolimus treatment without more efficiency that appeared later on was due to drug-drug interaction which was dealt with in an effective manner.
Evidence that Links the Drug to the Event: The timeline was consistent with the administration of carbamazepine for epilepsy attacks. A pharmacokinetic analysis showed a decrease in sirolimus and temsirolimus blood concentrations.
Management: Therapeutic drug monitoring of temsirolimus and sirolimus lead us to conclude that a threefold increase in the dose of temsirolimus was needed to ensure the effectiveness of treatment without adverse effects.
Conclusion: Clinicians should be aware of the potential drug interactions with mTor inhibitors in individuals using antiepileptic drugs. Close monitoring is necessary by measuring temsirolimus and/or sirolimus and/or everolimus concentrations in the blood.

Keywords: mTor inhibitors; Temsirolimus; Sirolimus