Syncope associated with concurrent amitriptyline and fluconazole therapy.
OBJECTIVE
To report on a 12-year-old white male with prostatic rhabdomyosarcoma who experienced episodes of syncope attributed to concurrent amitriptyline and fluconazole therapy, confirmed by readministration.


METHODS
The patient began experiencing syncopal episodes periodically over a seven-month period. These repeated episodes occurred when fluconazole was administered for periodic mucositis secondary to chemotherapy. The patient had received fluconazole in the past with no difficulty and had been receiving a stable dose of amitriptyline for neuropathic pain. On discontinuation of amitriptyline, no further episodes were noted.


CONCLUSIONS
Concurrent administration of fluconazole with amitriptyline likely resulted in the decreased metabolism of amitriptytine. Three case reports presented in the literature of adults receiving concurrent amitriptyline and fluconazole have shown an increase in serum amitriptyline concentrations with concurrent administration of fluconazole; however, none of these patients were rechallenged. Literature available on amitriptyline overdose confirms that syncope and the adverse events noted in the case studies may result from elevated amitriptyline plasma concentrations.


CONCLUSIONS
The consistent presentation of syncope in our patient during readministration of amitriptytine and fluconazole strongly suggests a drug-drug interaction.
Robinson
R F
RF
Fellow in Pediatric Pharmacotherapy, The Ohio State University, Children's Hospital, Columbus 43210-1291, USA.
Nahata
M C
MC
Olshefski
R S
RS
D000639:Amitriptyline / Q000009:adverse effects*; D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects*; D000935:Antifungal Agents / Q000009:adverse effects*; D002648:Child; D004347:Drug Interactions; D015725:Fluconazole / Q000009:adverse effects*; D006801:Humans; D008297:Male; D013575:Syncope / Q000139:chemically induced*
D000929:Antidepressive Agents, Tricyclic; D000935:Antifungal Agents; D000639:Amitriptyline; D015725:Fluconazole