Liverpool COVID-19 Interactions

Do Not Coadminister

Nirmatrelvir/ritonavir (5 days)

Colchicine

Quality of Evidence: Very Low

Summary:

Coadministration with nirmatrelvir/ritonavir has not been studied. Colchicine is a CYP3A4 and P-gp substrate. Coadministration of ritonavir (100 mg twice daily for 5 days) and colchicine (0.6 mg single dose) increased colchicine Cmax and AUC by 2.7-fold and 3.5-fold, respectively. In addition, there is the potential effect of inflammation to increase colchicine exposure so extreme caution is necessary. Unless there is a compelling reason to administer (with dose reduction) coadministration is not recommended. Note, coadministration of colchicine and P-gp inhibitors or strong CYP3A4 inhibitors is contraindicated in patients with renal or hepatic impairment.

Description:

Coadministration is contraindicated. Increased plasma concentrations of colchicine may result in serious and/or life-threatening reactions in patients with renal and/or hepatic impairment. Concentrations of colchicine are expected to increase when coadministered with ritonavir. Life-threatening and fatal drug interactions have been reported in patients treated with colchicine and ritonavir (CYP3A4 and P-gp inhibition).

Paxlovid GB Summary of Product Characteristics, Pfizer Ltd, December 2024.

Coadministration is contraindicated. Concentrations of colchicine are expected to increase when coadministered with ritonavir. Life-threatening and fatal drug interactions have been reported in patients treated with colchicine and ritonavir (CYP3A4 and P-gp inhibition). Concomitant use of colchicine with Paxlovid is contraindicated.

Paxlovid EU Summary of Product Characteristics, Pfizer, November 2024.

Co-administration may increase colchicine concentrations. Co-administration contraindicated due to potential for serious and/or life-threatening reactions in patients with renal and/or hepatic impairment.

Paxlovid US Prescribing Information, Pfizer Inc, November 2024.

Coadministration of ritonavir (100 mg twice daily for 5 days) and colchicine (0.6 mg single dose) was studied in 18 subjects. Ritonavir significantly increased colchicine Cmax and AUC (by 2.7-fold and 3.5-fold, respectively). Dosage adjustments of colchicine are required when given with CYP3A4 and/or P-gp inhibitors.

Novel evidence-based colchicine dose-reduction algorithm to predict and prevent colchicine toxicity in the presence of cytochrome P450 3A4/P-glycoprotein inhibitors. Terkeltaub RA, Furst DE, Digiacinto JL, et al. Arthritis Rheum, 2011, 63(8): 2226-37.