No pharmaceutical opinion available for this interaction.
Darunavir / ritonavir can inhibit the metabolism (CYP 3A4) and increase the plasma concentration of Carbamazepine.
Carbamazepine can induce the metabolism (CYP 3A4) and decrease the plasma concentration of Darunavir / ritonavir.
2C9, 2C19, 2C8 (moderate), UGT (moderate)
3A4 (strong), 2D6 (moderate), 2B6 (probable)
Probably without any clinical consequence.
No dosage adjustment recommended.
3A4 (main), 2C8, 1A2; Active metabolite: epoxide hydrolase (CBZ-10,11- epoxide)
3A4 (potent), 2C9, 2C19, P-gp, UGT and possibly 1A2
Possible increase of adverse effects.
No a priori dosage adjustment is recommended.
Monitor for adverse effects.
Monitor drug levels and adjust the dose if necessary.
A decrease in dosage of 25 to 50% may be necessary.
Gabapentin, pregabaline, leviracetam.
Carbamazepine adverse effects : disorientation, ataxia, lethargy, drowsiness, nausea, vomiting, headache, diplopia, dizziness, leukopenia and hyponatremia.
Ref #2241: The active metabolite of carbamazepine has decreased: AUC and Cmax by 54% and Cmin by 52% .
The author concluded that carbamazepine may need to be reduced by 25-50% but no dose adjustment for DRV/r is recommended.
Ref #3570: TDM data were evaluated 11 HIV-positive patients treated concomitantly with carbamazepine or oxcarbazepine and antiretrovirals for at least 3 months. All the TDM evaluations for carbamazepine and oxcarbazepine were within therapeutic ranges. TDM results of darunavir measured in these patients were comparable to those in the control group.
Ref #1304 : Reported case of a 20-year-old patient who developed vomiting, dizziness, elevated liver enzymes, and increased carbamazepine concentration by 87% following the addition of one dose of ritonavir 200 mg. Symptoms started within 12 hours after the first dose of ritonavir. In order to obtain a concentration within the therapeutic index, the dose of carbamazepine was reduced from 750 to 280 mg QD. Several other cases of acute toxicity to carbamazepine 2 to 4 days after the addition of ritonavir have been reported. See ritonavir + carbamazepine.
Ref #2090: Another case reported of a 50 year man who developed excessive drowsiness following the introduction of lopinavir/ritonavir and it was found that his serum carbamazepine concentration had increased by 46%. His antiretroviral therapy was then changed to nelfinavir 1250 mg BID but 3 days later the same symptoms appeared with 53% increase in carbamazepine. The symptoms of carbamazepine toxicity disappeared after a carbamazepine dose reduction of 33%. See lopinavir/ritonavir + carbamazepine.