Interaction Checker

Prescribing Resources

We have produced various materials in PDF format to aid the use of experimental agents in the treatment of COVID-19.

These resources are freely available and the Liverpool Drug Interactions Group would like to encourage the dissemination (with an appropriate acknowledgement) of this drug-drug interaction information for non-commercial use. If referencing these Prescribing Resources, it is important to include the publication date since these resources are updated as new data come to light. Please cite as: [Prescribing Resource Title], [PDF Publication Date], University of Liverpool, available from www.covid19-druginteractions.org, [accession date].

Evaluating the interaction risk - methods and metabolism

Evaluating the interaction risk of COVID-19 therapies

Updated November 2022

This document explains how we have evaluated the drug-drug interaction risk of the COVID-19 therapies (licensed and under clinical investigation) and gives details of their metabolism, interaction potential and cardiac effects.

Resources for nirmatrelvir/ritonavir (Paxlovid; 5 day administration)

Assessing a patient for treatment with Paxlovid

Updated March 2023

UPDATED

This flow chart shows how a patient may be assessed when considering treatment with Paxlovid (nirmatrelvir/ritonavir; NMV/r).

Interactions with selected outpatient medicines and Paxlovid

Updated May 2023

UPDATED - latest revisions to interactions added

This document allows users see at-a-glance the risk and management of drug-drug interactions between Paxlovid and selected drugs that may be used in the outpatient setting.

Interactions with selected WHO Essential Medicines and Paxlovid

Updated May 2023

UPDATED - Latest revisions and 9 new comedications added.

This document was developed for use in resource-limited settings where internet access is not always available and was designed to allow users see at-a-glance the risk and management of drug-drug interactions between Paxlovid and selected drugs from the WHO Essential Medicines list.

Guidance for Paxlovid dosing in patients with renal disease and patients on dialysis

Updated January 2024

UPDATED - new references added

This document summarises proposed dosing guidance for Paxlovid when administered to patients with renal impairment and to patients on dialysis.

Guidance for resuming paused or dose-adjusted comedications with Paxlovid

Updated May 2022

This document gives details of the duration of the CYP3A4 inhibitory effect of ritonavir and guidance as to how to manage comedications that may have been paused or dose-adjusted during treatment with Paxlovid (nirmatrelvir/ritonavir).

Administering Paxlovid as crushed tablets

Updated November 2022

UPDATED

Data supporting the crushing nirmatrelvir and ritonavir tablets for administration in cases of swallowing difficulties or via feeding tubes are given in this document.

Drug interactions when using Paxlovid for an extended duration

Updated October 2023

This document gives details of how the interaction profile of Paxlovid differs when used for a 5 day treatment duration or for an extended treatment duration.

Treatment Selectors and Interaction Summary Tables (All COVID Therapies)

"Treatment Selector" for Key COVID-19 Therapies

Updated December 2023

UPDATED - Nirmatrelvir/ritonavir (10 days or longer) and ~100 new comedications (including some herbal preparations) added.

Details of the nature of drug interactions with key COVID-19 therapies and many comedication classes are given in this PDF.

At-a-glance summary of interactions with COVID-19 antiviral therapies

Updated December 2023

UPDATED - Nirmatrelvir/ritonavir (10 days or longer) and ~100 new comedications (including some herbal preparations) added.

A summary of interactions with COVID-19 antiviral therapies (licensed or under clinical investigation) and over 1000 comedications are given in this PDF.

At-a-glance summary of interactions with COVID-19 host-directed therapies

Updated December 2023

UPDATED - Nirmatrelvir/ritonavir (10 days or longer) and ~100 new comedications (including some herbal preparations) added.

A summary of interactions with COVID-19 host-directed therapies (licensed or under clinical investigation) and over 1000 comedications are given in this PDF.

Prescribing and Dosing Guidance (All COVID Therapies)

Administration in cases of swallowing difficulties

Updated April 2023

UPDATED - ensitrelvir included and new information for NG/OG administration of molnupiravir added.

Advice for administering COVID-19 therapies (licensed or under clinical investigation) to patients who cannot swallow is given in this PDF.

Dose recommendations for patients with renal impairment

Updated September 2023

UPDATED - revised recommendations for remdesivir.

Details of dose modifications for COVID-19 therapies (licensed or under clinical investigation) which may be required for patients with renal impairment are given in this PDF.

Dose recommendations for patients with hepatic impairment

Updated September 2023

UPDATED - revised recommendations for remdesivir.

Details of dose modifications for COVID-19 therapies (licensed or under clinical investigation) which may be required for patients with hepatic impairment are given in this PDF.

Academic Sponsors / Collaborators
Editorial Sponsors / Research Funders