hene A dose decrease may be needed for these drugs when co-administered with ritonavir.
Anesthetic:
meperidine ↓ meperidine/ ↑normeperidine (metabolite) Dosage increase and long-term use of meperidine with ritonavir are not recommended due to the increased concentrations of the metabolite normeperidine which has both analgesic activity and CNS stimulant activity (e.g.,seizures).
Antialcoholics:
disulfiram/ metronidazole Ritonavir formulations contain alcohol, which can produce disulfiram-like reactions when co-administered with disulfiram or other drugs that produce this reaction (e.g.,metronidazole).
Antiarrhythmics:
disopyramide, lidocaine, mexiletine ↑antiarrhythmics Caution is warranted and therapeutic concentration monitoring is recommended for antiarrhythmics when co-administered with ritonavir, if available.
Anticancer Agents: vincristine, vinblastine ↑ anticancer agents Concentrations of vincristine or vinblastine may be increased when co-administered with ritonavir resulting in the potential for increased adverse events usually associated with these anticancer agents.
Consideration should be given to temporarily withholding the ritonavir containing antiretroviral regimen in patients who develop significant hematologic or gastrointestinal side effects when ritonavir is administered concurrently with vincristine or vinblastine. Clinicians should be aware that if the ritonavir containing regimen is withheld for a prolonged period, consideration should be given to altering the regimen to not include a CYP3A or P-gp inhibitor in order to control HIV-1 viral load.
Anticoagulant: warfarin ↓ R-warfarin
↓↑ S-warfarin Initial frequent monitoring of the INR during ritonavir and warfarin co-administration is indicated.
Anticonvulsants:
carbamazepine, clonazepam, ethosuximide ↑anticonvulsants Use with caution. A dose decrease may be needed for these drugs when co-administered with ritonavir and therapeutic concentration monitoring is recommended for these anticonvulsants, if available.
Anticonvulsants:
divalproex, lamotrigine, phenytoin ↓anticonvulsants Use with caution. A dose increase may be needed for these drugs when co-administered with ritonavir and therapeutic concentration monitoring is recommended for these anticonvulsants, if available.
Antidepressants:
nefazodone, selective serotonin reuptake inhibitors (SSRIs), tricyclics ↑antidepressants A dose decrease may be needed for these drugs when co-administered with ritonavir.
Antidepressant:
bupropion
↓ bupropion
↓ active metabolite, hydroxybupropion
Concurrent administration of bupropion with ritonavir may decrease plasma levels of both bupropion and its active metabolite (hydroxybupropion). Patients receiving ritonavir and bupropion concurrently should be monitored for an adequate clinical response to bupropion.
Antidepressant:
desipramine ↑ desipramine Dosage reduction and concentration monitoring of desipramine is recommended.
Antidepressant: trazodone ↑ trazodone Concomitant use of trazodone and NORVIR increases plasma concentrations of trazodone. Adverse events of nausea, dizziness, hypotension and syncope have been observed following co-administration of trazodone and NORVIR. If trazodone is used wi
