The COVID drug Paxlovid has been available in Australia under the Pharmaceuticals Benefits Scheme (PBS) since early May, with eligible patients being advised to contact their GP for a prescription.
Paxlovid is an oral treatment for mild COVID that is taken as a tablet and contains two active ingredients: nirmatrelvir and ritonavir. 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 potential benefits and side effects of using this drug for mild COVID?
Read more: What is Paxlovid and how does it help fight the coronavirus? An infectious disease doctor answers questions about the COVID-19 pill
How effective is it?
Evidence of the effectiveness of Paxlovid comes from a study that compared it to placebo (an inactive treatment) in 2,246 unvaccinated adults with mild to moderate COVID-19 infection. They had risk factors for serious illness but did not require hospitalization.
The group that took Paxlovid had a lower chance of being hospitalized, at a rate of eight per 1,000 people. This compares to 63 out of 1,000 in the group who 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 did not include children, adolescents, pregnant or breastfeeding women, or people who had been vaccinated, so the safety and effectiveness of Paxlovid in these groups is less certain. More research into these groups and in comparison to other treatments would be very helpful.
The study was also conducted before the Omicron variant was released. There is no data specifically on the effectiveness of Paxlovid against Omicron, but there is no particular reason to think it would be any less effective.
What are the disadvantages?
The main disadvantage of Paxlovid is that it can cause serious side effects when combined with many commonly used medications for a variety of other conditions.
In some cases, people taking these medications should not receive Paxlovid; in other cases, it may be possible to interrupt or change the dose of the other drug for the five days that you take Paxlovid.
It’s important to discuss all your medications – including herbal and non-prescription medications, and any plans to change them – with your doctor and pharmacist before starting treatment with Paxlovid.
Drug interaction checkers can help identify which drugs might interact with it. Detailed information on potential drug interactions is available in the Therapeutic Goods Administration Product Information for Paxlovid.
Other commonly reported side effects include headaches, diarrhea, vomiting, and altered taste, or “paxlovid mouth,” where foods taste metallic, sour, or bitter.
There have been some reports of people having COVID symptoms again after completing their Paxlovid cycle. Researchers and health officials are constantly looking for signs of harm associated with taking the drug.
READ ALSO: COVID Made Things Taste Strange, Now ‘Paxlovid Mouth’ Sounds Disgusting. What causes dysgeusia?
What are the risk factors for severe COVID?
Paxlovid is most helpful for people with mild COVID symptoms who are at high risk of developing serious illness. Because it prevents the virus from making copies of itself, to be effective, it must be started within five days of the onset of COVID symptoms.
The study that showed the effectiveness of Paxlovid included unvaccinated people with one or more of these risk factors for progression to severe COVID-19 disease:
Age 60 or older (although the Australian limit is 65)
Diabetes that requires medication
Obesity (defined in the study as a BMI of 25 kg/m² or more)
high blood pressure
chronic lung disease.
There are other people who are at higher risk of serious illness from COVID who could benefit from Paxlovid. These include some people with impaired kidney function, compromised immune function due to drugs or HIV infection, severe disability, some cancers, and blood disorders.
If you are unvaccinated, partially vaccinated, or fully vaccinated but have a combination of these risk factors, and have mild COVID for the first few days of symptoms, your doctor may recommend Paxlovid.
How do I access Paxlovid?
Paxlovid must be prescribed by a doctor or healthcare professional.
It is listed on the PBS for adults who have mild to moderate COVID that has been confirmed by a PCR or a positive rapid antigen test result confirmed by a doctor or nurse, and who have had symptoms within five days of onset treatment can begin. This means the prescription costs AUD$42.50 (or $6.80 for health card holders).
People who meet the following criteria can get a prescription for PBS-subsidized Paxlovid from their doctor if they:
Age 65 or older with two other risk factors for serious illness
Are 75 years or older with another risk factor for serious disease (as increasing age is a risk factor)
identify as Aboriginal or Torres Strait Islander and are at least 50 years of age and have two other risk factors for serious illness
are moderately to severely immunocompromised.
Other drugs are available to treat mild COVID in people who are at risk of developing serious illness. Each of the drugs has advantages and disadvantages. Your doctor will discuss with you the best treatment options available.
Paxlovid is not a treatment for people who are very unwell with COVID. If you are hospitalized with COVID, your clinical team will discuss other treatment options with you.
Read more: I’m at home with COVID. When do I have to see the doctor? And what treatments are there?