Date of report 22 Jun 2020
Reported case interaction between
 Ritonavir and Triamcinolone

FLS Science

Drugs suspected to be involved in the DDI

Perpetrator
Ritonavir
Daily Dose
200 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
June 1, 2002
End date
Ongoing
Victim
Triamcinolone
Daily Dose
40 (mg)
Dose adjustment performed
No
Administration Route
Other
Start date
June 18, 2019
End date
June 18, 2019

Complete list of drugs taken by the patient

Antiretroviral treatment
Darunavir (with Ritonavir or Cobicistat)
Etravirine
Complete list of all comedications taken by the patient, included that involved in the DDI

Triamcinolone; Metformin (850 mg /12h); Enalapril 10 (mg/12h); Atorvastatin (40 mg/24h)

Clinical case description

Gender
Male
Age
53
eGFR (mL/min)
>60
Liver function impairment
No
Description

53 years old man diagnosed with HIV in 1993. ART was initiated in 1993 and he has needed several changes of the ART regimens because virological failures and resistance selection. Since 2006 plasma viral load is persistently undetectable. Current ART (DRV/r 600/100 mg BID + ETR 200 mg BID) was initiated in 2009. Current CD4+ T cell count is 583/µL (29%). He also presents other co-morbidities: obesity (BMI 29.26), diabetes mellitus, dyslipidemia and hypertension. In June 2019 he was diagnosed with subacromial subdeltoid bursitis that was treated with triamcinolone (40 mg, single dose) administered as subacromial bursa injection. Despite the interaction between triamcinolone and darunavir/ritonavir (Triamcinolone is metabolised by CYP3A4 and coadministration with ritonavir-boosted darunavir can highly increase concentrations of triamcinolone and cause Cushing syndrome and/or adrenal suppression) this treatment was well tolerated and no adverse effects were observed.

Clinical Outcome

No unwanted outcome

Editorial Comment

Coadministration is not recommended unless the potential benefit of treatment outweighs the risk of systemic corticosteroid effects. Triamcinolone is metabolised by CYP3A4 and coadministration with boosted PIs could increase concentrations of triamcinolone. There are several case reports of Cushing's syndrome with the use of intra articular triamcinolone injections in patients on boosted PIs, even after a single dose (as in this clinical case). A reduced dose of methylprednisolone has been suggested as a possible safer alternative to triamcinolone injection although there is insufficient information to indicate whether other injectable steroids present a lower risk than triamcinolone.

University of Liverpool Recommendation

These drugs should not be coadministered
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