https://interactions.guidetherapeutiquevih.com/en/interaction-details?id=1225

Ritonavir

Rifampicin

Contraindicated.

No pharmaceutical opinion available for this interaction.

Mechanism

Rifampicin may possibly induce the metabolism (CYP 3A4) and consequently decrease the concentration of Ritonavir.

Ritonavir

Pharmacodynamic effects

Possible decrease of clinical efficacy.

Risk of a possible development of resistance to antiretroviral class.

Recommendations

–

Alternative solution(s)

In patients without resistance to integrase inhibitors, dolutegravir 50 mg BID or raltegravir 800 mg BID : see dolutegravir + rifampicin or raltegravir + rifampicin.

Rifampicin

Pharmacodynamic effects

Increased risk of hepatotoxicity.

Recommendations

Contraindicated. Use alternative.

Alternative solution(s)

Rifabutin either 150 mg QD, every 2 days or 3 times a week (see rifabutin with PIs) or choose an antibiotic that does not interact with PIs.

Monitor

Hepatotoxicity: elevation of hepatic transaminases by 3 to 5 fold, fatigue, unusual weakness, nausea, vomiting, anorexia, abdominal pains, pale stools, dark urine, jaundice.

Tests

–

Pharmacokinetic parameters
Parameters
Reference number
# patients
AUC
Cmax
Dose
Frequency
Duration (days)
Cmin
HIV
Ritonavir
122 1443
7 8
- 35%  
- 25%  
500 mg 600 mg
Q12H Q12H
20 56
- 49% *
  +
Rifampicin
122 1443
7 8
   
   
300-600 mg 600 mg
QD QD
10 56
   
  +
Comment

* Cmin values ranged from 350 to 5630 ng/mL and were above 650 ng/mL in all but one subject.

Co-administration of rifampicin 600 mg QD with protease inhibitors such as lopinavir/ritonavir, darunavir/ritonavir, atazanavir/ritonavir and atazanavir alone causes a decrease in AUC and Cmin of approximately 75% to 80%.

Ref #3116 : To increase the chance of achieving therapeutic serum levels and reduce the development of resistance and treatment failures some experts, as well as the CDC, recommend a 150mg QD dose. See rifabutin + PIs.

Comment
Reference
  • 1
    Tatro DS, Olin BR, Hebel SK et al. Drug Interaction Facts, St-Louis, Missouri: Facts and comparaisons, 2007.
  • 6
    Hansten PD et Horn JR. Drug interactions analysis and management. Applied therapeutics inc. Washington, USA 2000.
  • 122
    Ritonavir (Norvir), Corporation AbbVie, Quebec, Canada, 5 juillet 2021.
  • 144
    Cotton DJ. Treating concurrent HIV and TB: A clinical alert from the CDC. AIDS Clin Care. 1996;8(12):97-99.
  • 289
    Sun E, Heath-Chiozzi M, Cameron DW et al. Concurrent ritonavir and rifabutin increases risk of rifabutin-associated adverse events. 11th International Conference on AIDS Vancouver;1996. Abstract Mo. B. 171.
  • 402
    Strayhorn VA, Baciewicz AM and Self TH. Update on rifampin drug interactions. Arch Intern Med 1997;157:2453-2458.
  • 1443
    Moreno S, Podzamczer D, Blazquez R, et al. Treatment of tuberculosis in HIV-infected patients: safety and antiretroviral efficacy of the concomitant use of ritonavir and rifampin.[Letter] AIDS. 2001 June;15(9):1185-1187.
  • 3116
    Center for Disease Control and prevention. Managing Drug Interactions in the Treatment of HIV-Related Tuberculosis. Disponible: http://www.cdc.gov/tb/publications/guidelines/tb_hiv_drugs/recommendations03.htm Publié le 22 sept 2014. Consulté le 11 janvier 2018.