The drug for COVID-19 Paxlovid has been available in Australia under the Pharmaceutical Benefits Plan (PBS) since early May, with eligible patients directed to speak with their GP for a prescription.
Paxlovid is an oral treatment for mild COVID, taken as a tablet, that has two active ingredients: nirmatrelvir and ritonavir. Taken together, they reduce the ability of SARS-CoV-2, the virus that causes COVID, to multiply in your body.
So who should access Paxlovid? And what are the possible benefits and side effects of using this drug for mild COVID?
Read more: What is Paxlovid and how will it help fight the coronavirus? An infectious disease doctor answers questions about the COVID-19 pill
How effective is it?
Evidence for the effectiveness of Paxlovid comes from a study comparing it with a placebo (an inactive treatment) in 2,246 unvaccinated adults who had mild to moderate COVID. They had serious disease risk factors but did not need hospitalization.
The group that took Paxlovid was less likely to be admitted to the hospital, with a rate of eight per 1,000 people. This compares to 63 per 1,000 in the group that did not receive Paxlovid – a big reduction.
Paxlovid can also prevent people from dying from COVID, although this is less clear, as there were only a small number of deaths in the study.
The study found that taking Paxlovid reduced the chance of needing to be hospitalized for severe COVID. Shutterstock
The study did not include children, adolescents, pregnant or lactating women or people who had been vaccinated, so the safety and efficacy of Paxlovid in these groups is less certain. More research in these groups, and compared to other treatments, would be very helpful.
The study was also conducted before the Omicron variant circulated. There are no data on the effectiveness of Paxlovid against Omicron specifically, but there is no particular reason to think that it would be less effective.
What are the drawbacks?
The biggest drawback of Paxlovid is that it can cause serious side effects if combined with many commonly used drugs for a wide range of other conditions.
In some cases, people taking these drugs should not receive Paxlovid; in other cases, it may be possible to stop or change the dose of the other medicine during the five days you are taking Paxlovid.
It is important to discuss all of your medications, including herbal and over-the-counter medications, and any plans to change them, with your doctor and pharmacist before starting Paxlovid.
Drug interaction checkers can help identify which drugs may interact with it. Detailed information on possible drug interactions can be found in the Paxlovid Therapeutic Product Administration product information.
Other commonly reported side effects include headache, diarrhea, vomiting, and dysgeusia, or “mouth Paxlovid,” where food tastes metallic, sour, or bitter.
There are some reports of people experiencing symptoms of COVID again after completing the Paxlovid course. Researchers and health authorities are continuously monitoring emerging evidence of the damage associated with taking the drug.
Read more: COVID made things taste weird, now “Paxlovid’s mouth” sounds disgusting. What causes dysgeusia?
What are the serious risk factors for COVID?
Paxlovid is very useful for people with mild symptoms of COVID who are at high risk of developing a serious illness. Because it works by preventing the virus from making copies of itself, to be effective, it must be started within five days of the development of COVID symptoms.
The study that showed the effectiveness of Paxlovid included people who were not vaccinated with one or more of the following risk factors for progressing to severe COVID disease:
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60 years or older (although the Australian limit is 65)
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diabetes requiring medication
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obesity (defined in the study as a BMI of 25 kg / m² or more)
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heart disease
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high blood pressure
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chronic lung disease.
Older people with chronic illnesses are at higher risk for severe COVID-19. Shutterstock
There are other people who are at higher risk for serious COVID disease and may benefit from Paxlovid. This includes some people with reduced kidney function, reduced immune function due to medication or HIV infection, severe disability, some cancers and blood disorders.
If you are not vaccinated or are partially vaccinated, or are fully vaccinated but have a combination of these risk factors, and you have mild COVID in the first few days of symptoms, your doctor may recommend Paxlovid.
How do I access Paxlovid?
Paxlovid should be prescribed by a doctor or nurse.
PBS is included for adults who have mild to moderate COVID confirmed by PCR or a positive fast antigen test verified by a doctor or nurse, and who can start treatment within five days of the onset of symptoms. That means the prescription will cost A $ 42.50 (or $ 6.80 for health card holders).
People who meet the following criteria can get a PBS-subsidized Paxlovid prescription from their doctor or nurse if:
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they are 65 years of age or older, with two other risk factors for serious illness
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You are 75 years of age or older with another risk factor for serious illness (as increasing age is a risk factor)
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they are identified as aboriginal or island in the Torres Strait and are 50 years of age or older with two other risk factors for serious illness.
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they are immunocompromised from moderate to severe.
There are other medications available to treat mild COVID in people who are at risk of developing a serious illness. Each of the medications has pros and cons. Your doctor will discuss with you the best treatment options available.
Paxlovid is not a treatment for people who are very ill with COVID. If you are in the hospital with COVID, your clinical team will discuss other treatment options with you.
Read more: I’m at home with COVID. When should I see a doctor? And what treatments are available?