Guidelines say Paxlovid more effective than Lagevrio – yet prescribing rates appear to be similar

GPs are still recommending Lagevrio (molnupiravir) almost as often as Paxlovid (nirmatrelvir/ritonavir), despite evidence that it lags far behind in effectiveness, Healthed’s latest survey suggests.

In December, the National Clinical Evidence Taskforce updated their guidelines to recommend against the routine use of Lagevrio. The move came after a large open-label randomised controlled trial in the UK “found that molnupiravir does not have an impact on hospitalisation or mortality in vaccinated adults with mild COVID-19 and at least one risk factor for disease progression.”

An administrative note on the molnupiravir PBS listing states that the drug should only be considered if nirmatrelvir and ritonavir is contraindicated or otherwise unsuitable.

However, Healthed’s survey suggests that many GPs are still recommending Lagevrio, though Paxlovid prescribing is on the rise.

When Healthed surveyed GPs about the two antiviral treatments in June, more GPs were recommending Lagevrio to their patients than were recommending Paxlovid, but the latest data shows that trend has reversed.

• In a survey of more than 1600 GPs, slightly more GPs (31%) had recommended Paxlovid to one or more patients in the past week, compared with 27% who had recommended Lagevrio.
• But the proportion of GPs recommending Paxlovid has increased significantly since Healthed’s previous survey in June, when only 18% had recommended it in the past week.
• And slightly fewer GPs are recommending Lagevrio now; 27% in March compared with 31% in June.

Dr Alexander Padiglione, an infectious diseases physician at Monash Medical Centre and The Alfred Hospital, said there is “fairly clear evidence” that Paxlovid is the more effective agent, and hence is preferred unless there are contraindications.

The Taskforce said non-routine use of molnupiravir could be considered in “specific circumstances for the highest risk patients, where all other treatment options are contraindicated or inappropriate,” but noted that evidence is limited in the highest risk patients, such as those who are highly immunosuppressed or in residential aged care.

So why are many GPs still reluctant to prescribe Paxlovid?

When Healthed asked GPs about barriers, 58% said concerns about drug interactions prevents them from prescribing Paxlovid more often. Almost one fifth of GPs (19%) said they are also concerned about side effects.

Dr Padiglione has years of experience managing the risk of drug interactions in patients with HIV. He says there are excellent tools available, such as the University of Liverpool interaction checker which allows doctors to rapidly check if there are significant interactions. The Liverpool site uses a ‘traffic light system’ to tell you if the drug should not be used at all (red), if it’s totally fine (green) or if some adjustments or precautions may be necessary (yellow).

“Hopefully using those tools will make it easier for GPs to prescribe these drugs. In some complicated patients, thinking and planning ahead might also be useful. For example, there are some drugs that might interact, but could be safely withheld for a period of time whilst they’re on the Paxlovid. So those sorts of planning ahead kind of decisions could also assist in using this drug”, Dr Padiglione explained.

“GPs can be reassured that there is a wealth of experience with prescribing this drug, internationally and here in Australia, and it’s an extremely safe and highly effective drug.”

“Like all drugs, it’s a familiarity issue… the first couple of times that we prescribe these drugs they feel unfamiliar and we’re a bit uncertain, but we have tools at our hand to assist prescribing to ensure that we don’t get interactions,” Dr Padiglione said.

He said GPs can also seek assistance from pharmacists, adding that “it’s also their responsibility, not just ours, to ensure safe prescribing”. He noted that the Alfred Hospital has a hotline staffed with pharmacists to assist GPs with prescribing, available on (03) 8290 3801 from 8am to 5pm seven days per week.

However, Dr Padiglione also acknowledged the difficulties in keeping up with changing guidelines, especially in the GP setting where there is less support from pharmacists and significant time pressures.

RACGP says prescribing decisions should be made on a case by case basis

Dr Glynn Kelly, Chair, RACGP Disaster Management Specific Interest Group, said “Not everyone who tests positive for COVID-19 will benefit from oral antiviral medications,” and that GPs should assess the appropriateness of these medicines “based on the person’s individual risk for disease progression, medical history, current medicines, age, and COVID-19 vaccination status, including time since vaccination”.

“I note that the survey results show a minority of GPs are using Lagevrio and Paxlovid, and typically not more than once a week among those who do prescribe these medications. Given the contraindications for both medications, this is not unexpected, but the RACGP advises GPs to follow the Taskforce’s recommendation that Lagevrio (molnupiravir) should only be used where all other treatment options are inappropriate”.

Hear from Associate Professor Nigel Crawford, ATAGI Chair, at Healthed’s upcoming COVID update. Register here.

A total of 1,774 GPs responded to Healthed’s survey, which opened on 7 March 2023. GPs were allowed to skip questions, which is why each question has a different number of GP participants.

Credits

Survey conception and design– Dr Ramesh Manocha
Survey analysis and visualisation; Reporting – Yasmin Clarke
Editing – Lynnette Hoffman