https://interactions.guidetherapeutiquevih.com/en/interaction-details?id=11435
https://interactions.guidetherapeutiquevih.com/en/interaction-details?id=11435
No pharmaceutical opinion available for this interaction.
Carbamazepine can induce the metabolism (CYP 3A4) and decrease the plasma concentration of Atazanavir / ritonavir.
Atazanavir / ritonavir may possibly inhibit the metabolism (CYP 3A4) and consequently increase the plasma concentration of Carbamazepine.
Possible decrease of clinical efficacy.
Monitor for signs and symptoms of therapeutic failure.
Should not be administered without low-dose ritonavir or cobicistat.
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Possible increase of adverse effects.
Avoid if possible. Use an alternative or monitor patient closely.
A reduction in dosage may be necessary.
See comments for further details.
As clinically indicated : brivaracetam, gabapentin, lacosamide, lamotrigine, levetiracetam, pregabalin, rufinamide, topiramate, vigabatrin, zonisamide.
Carbamazepine adverse effects : disorientation, ataxia, lethargy, drowsiness, nausea, vomiting, headache, diplopia, dizziness, leukopenia and hyponatremia.
Atazanavir plasma level
Carbamazepine
CD4+
Viral load HIV
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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. Conversely, trough concentrations for atazanavir demonstrated significantly lower values when compared with values usually measured in HIV-infected patients not treated with antiepileptic drugs.
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.