Date of report 16 Jul 2024
Reported case interaction between
Cobicistat and DROSPIRENONE

FLS Science

Drugs suspected to be involved in the DDI

Perpetrator
Cobicistat
Daily Dose
150 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
March 10, 2020
End date
May 2, 2024
Victim
DROSPIRENONE
Daily Dose
4 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
April 16, 2024
End date
Ongoing

Complete list of drugs taken by the patient

Antiretroviral treatment
Darunavir/Cobicistat/Emtricitabine/Tenofovir-AF
Complete list of all comedications taken by the patient, included that involved in the DDI

Drospirenone 4mg/d

Citalopram 10mg/d

 

Clinical case description

Gender
Female
Age
35
eGFR (mL/min)
>60
Liver function impairment
No
Description

A female patient with HIV had a history of poor adherence to ART, leading to a switch from RPV/FTC/TAF to DRVc/FTC/TAF in 2020. She had a medical history of depression, for which she was on citalopram therapy, and ovarian cysts. For the latter, her gynecologist prescribed drospirenone without checking for potentially relevant drug-drug interactions (DDIs). Despite not experiencing any adverse events (which may be more frequent due to increased exposure to drospirenone), at her next visit with her HIV doctor, ART was modified to BIC/FTC/TAF.

Most guidelines recommend removing PK enhancers whenever possible to avoid risky DDIs with drugs that may be prescribed by other healthcare professionals.

Clinical Outcome

No unwanted outcome

Editorial Comment

Cobicistat is a potent inhibitor of CYP3A4 which is involved in drospirenone metabolism.  Drospirenone AUC increased by 58% when a combined oral contraceptive containing drospirenone and ethinylestradiol was coadministered with darunavir/cobicistat. When darunavir/cobicistat is coadministered with a drospirenone-containing product, clinical monitoring is recommended due to the potential for hyperkalaemia.

University of Liverpool Recommendation

Potential interaction - may require close monitoring, alteration of drug dosage or timing of administration
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