[Carbamazepine and clarithromycin: a clinically relevant drug interaction].
BACKGROUND
Carbamazepine is associated with clinically relevant drug interactions especially with macrolide antibiotics such as troleandomycin and erythromycin. These drugs inhibit the metabolism of carbamazepine. Clarithromycin, a macrolide antibiotic similar to erythromycin, is widely used to treat respiratory tract infections and is used for the treatment of atypical mycobacterial infections and Helicobacter pylori-associated peptic ulcer disease.


METHODS
To report an interaction between carbamazepine and clarithromycin, we present a study that includes three regular attenders at the epilepsy department of Montpellier and seven cases reported by the French national drug safety center.


RESULTS
In patients receiving carbamazepine alone or in combination with other drugs, administration of clarithromycin led to a transitory overdosage (ataxia, dizziness, diplopia, nausea, vomiting, drowsiness). Blood level was available in 8 patients with a concentration of carbamazepine ranging from 13.3 to 28.5 mg/l.


CONCLUSIONS
Carbamazepine is extensively metabolized by cytochrome P450 enzymes, especially CYP34A. As clarithromycin is also metabolized by CYP3A4, this drug has the propensity to inhibit the metabolism of carbamazepine. Clarithromycin should be thus avoided in patients taking carbamazepine.
Gélisse
P
P
Unité Médico-Chirurgicale de l'Epilepsie, Hôpital Gui-de-Chauliac, Montpellier. p-gelisse@chu-montpellier.fr
Hillaire-Buys
D
D
Halaili
E
E
Jean-Pastor
M-J
MJ
Vespignan
H
H
Coubes
P
P
Crespel
A
A
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D000927:Anticonvulsants / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D002220:Carbamazepine / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D017291:Clarithromycin / Q000009:adverse effects* / Q000627:therapeutic use; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004347:Drug Interactions; D062787:Drug Overdose; D004828:Epilepsies, Partial / Q000150:complications / Q000188:drug therapy; D004827:Epilepsy / Q000150:complications / Q000188:drug therapy; D017034:Epilepsy, Frontal Lobe / Q000150:complications / Q000188:drug therapy; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male
D000900:Anti-Bacterial Agents; D000927:Anticonvulsants; D002220:Carbamazepine; D003577:Cytochrome P-450 Enzyme System; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D017291:Clarithromycin