Paracetamol is one of the most ubiquitous and multipurpose medications. It is also affordable and easily accessible. Everyone in the world would have at least taken a tablet during their lifetime. Most of the time paracetamol is used to relieve fever. This action is such a common practice especially as the world vaccinates everyone against COVID-19 because one of the commonest side effects of the vaccine is fever and sore arm. However, certain people try to get in front of these side effects and take paracetamol before their vaccine administration. Is this advisable? What are the outcomes of taking paracetamol before COVID-19 vaccine?
What is Paracetamol and how does it work?
Paracetamol is an active ingredient that has analgesic, antipyretic and weak anti-inflammatory properties. Its analgesic action is evidenced by preventing pain impulse generation via peripheral blockage. It also acts on the hypothalamic temperature-regulating centre that offset raised body temperature and fever. In addition it also acts on CNS (central nervous system) prostaglandin synthesis inhibition, giving weak anti-inflammatory actions. Hence why it is commonly prescribed as antipyretic and analgesics.
It is usually taken orally in the form of tablets for adults and liquid for children. Other less common routes of intake are IV and rectal suppository, depending on doctors’ advice. It takes less than one hour to achieve the intended effect. As paracetamol enters the body, it moves from the gut into the liver to be metabolized into NAPQI (N-acetyl-p-benzoquinone). There are also a myriad of drugs that metabolize at the liver, therefore, it is very important to inform doctors or pharmacists if you are on any type of medications beforehand. After the metabolization, paracetamol will be excreted in the urine at a half-life rate of 1 to 3 hours.
Who can and cannot use paracetamol?
MIMS (Monthly Index of Medical Specialties) Malaysia outlined that the use of paracetamol is indicated in treating symptoms of fever, post-immunisation fever and mild to moderate pain. For the purpose of post-vaccine fever control, the suggested dose for normal adults is 1g Paracetamol every 3-hourly.
It is not suitable for individuals with severe liver dysfunction, currently diagnosed with liver disease or history of hypersensitivity with paracetamol.
In some instances, paracetamol can be used but only on doctors’ observation and prescription. This special precautions are mainly for the people listed below:
- Pregnant and breastfeeding women
- Children
- Chronic dehydration or malnutrition
- Alcoholics
- Weight below 50kg
- Liver and kidney impairment
- G6PD (glucose-6-phosphate dehydrogenase) deficiency
Is it safe to be used before COVID-19 vaccination? Why or why not?
First and foremost, there is no evidence of alleviating vaccine side effects by the use of oral antipyretics and analgesia before vaccine administration. This means, consumption of paracetamol before vaccine injection is of no benefit at all.
Secondly, the WHO (World Health Organisation) agrees that painkillers such as paracetamol should not be taken before vaccination. Since the development of COVID-19 vaccine is still recent, they worry that painkillers will disrupt vaccine efficacy if taken before injection. These painkillers are not limited to paracetamol, it includes aspirin, acetaminophen and ibuprofen. However, if you are already on these medications for an underlying condition, do consult your doctors before vaccination.
How long does paracetamol stay in the body? When can you take COVID-19 vaccine?
Rapidly after paracetamol ingestion, it will be absorbed via the gut and instantaneously go through an excretion process after being metabolized. It stays in the body for 24 hours before being excreted completely via urine. Hence, if you took paracetamol, it is advisable to change your vaccination date to another day if possible. Please ensure the new appointment is more than 24 hours from the time of paracetamol intake.
Conclusion
In conclusion, paracetamol or painkillers should only be taken after COVID-19 vaccine injection. It does help in managing vaccine side effects when taken according to recommended dosage.