How does Paxlovid, the new COVID-19 pill work?

The corona virus consists of components that include proteins, RNA, and these components give

rise to virus particles that are functional and cause disease. Paxlovid is a new pill that can block the action of some of the functional proteins, resulting in a virus that is defective and unable to function.

The virus infects the cells. After that, it copies its RNA genome, transforms that RNA into proteins, & then assembles proteins into a new form of viruses (virions).

During the conversion of RNA to protein, some of the proteins are first strung together, but they still need to be freed from each other to perform their job. The 'molecular scissor' that can free these proteins is called protease. If the protease does not separate the proteins, the virus can't copy itself.

Paxlovid is the magic Drug that holds the protease and then neutralizes it & prevents the virus from replicating. Pfizer's scientists have created Paxlovid with the X-rays of the Advanced Photon method.

People at a high risk of severe COVID-19 need to consult with their physicians and a pharmacist in advance of needing Pfizer's oral pill called Paxlovid, because medications can interact harmfully with coronavirus treatment.

Claims Regarding the Drug

Pharmacists are very confident that most people take Paxlovid very safely. Physicians and pharmacists might advise certain people to adjust their medications taken for other conditions to ensure they are safe. People should only make these decisions with the advice of related experts.

Composition of the Drug

The Paxlovid pill comprises two tablets of the antiviral drug nirmatrelvir and one tablet of the drug ritonavir; this Drug has long been used as a boosting agent in HIV treatment. Ritonavir decreases the function of a key liver enzyme called CYP3A, which can metabolize many medications, such as nirmatrelvir. In the case of Paxlovid treatment, ritonavir can slow down the body's breakdown of the antiviral and help it stay at a therapeutic level for a longer period.

Interaction of the Drug

When this Drug Paxlovid is given with any other medication also metabolized by CYP3A enzyme, the main worry is that the drug ritonavir component can boost the drugs administered together to toxic levels.

The drugs that can pose interaction risks are commonly prescribed to people at the greatest risk of COVID complications because of co morbid health conditions.

The medications are but are not only limited to: certain blood thinners; some anti-seizure medications; a few drugs for irregular heart rhythms, high blood pressure, and increased cholesterol; antidepressants and certain anxiety medications; such as immunosuppressant’s; certain steroids (including inhalers); HIV treatment; and medicines for erectile dysfunction.

Challenges with the Drug

Many challenges can prevent people from using the complete power of the tool. The first is not a sufficient supply of the Drug. The US has made a contract to receive pills that can cover 65,000 Americans in the upcoming week. With current daily cases of 242,794 people affected nationwide, that wouldn't cover half of the people contracting the virus daily. Pfizer should be working with other manufacturers simultaneously to increase production. 

Recommendation of Usage

The COVID treatment protocol is to use nirmatrelvir 300 mg along with ritonavir 100 mg (Paxlovid) by oral mode twice for five days in patients who are not in the hospital with mild and moderate COVID-19 cases in ages greater than 12 years and weight greater than 40 kg who are at a high risk of disease; the treatment should be started as soon as possible and in 5 days of the start of symptoms.

• Ritonavir and nirmatrelvir have great and complex drug interactions, mainly due to the ritonavir part of the combination.
• Before giving ritonavir-boosted nirmatrelvir, clinicians must carefully review the patient's history and medications, including OTC medications, any herbal supplements they are taking, and drugs used for recreational purposes, to evaluate the potential drug-drug interactions.

Side effects of the Drug

The common side effects of ritonavir and nirmatrelvir are diarrhea, dysgeusia, hypertension, and body aches.

The dose needs to be reduced to nirmatrelvir 150 mg and ritonavir 100 mg two times daily in patients with a  moderate renal issue (i.e., those with a glomerular filtration rate of greater than 30 and less than 60 mL/min). Ritonavir and nirmatrelvir are not advised to patients with an eGFR of greater than 30 mL/min until more data are available. The dose for patients with the severe renal issue has not been determined.

Ritonavir-boosted nirmatrelvir is not advised for patients with a severe hepatic issue (i.e., Child-Pugh Class C). It needs to be used with care in patients with already existing liver diseases, liver abnormalities of enzymes, or hepatitis. No pharmacokinetics are available for this patient population.

Conclusion

Despite the impact that antiviral drugs can have over the pandemic, one must still proceed with care and test the Drug enough to administer to people. The patient's history needs to be taken, and more clinical trials should occur. People need to know the potential side effects that can affect their health. On the other hand, this major advancement will pave the way for more research on COVID treatment.