Paxlovid: Pfizer, Prescription, Price, Contraindications

The drug Paxlovid, produced by Pfizer, is prescribed in France against covid infection. The Haute Autorité de Santé is in favor of its reimbursement. What are the indications for Paxlovid? What is the composition? His price? The contraindications and side effects? Its effectiveness against Omicron?

the Paxlovíd is a drug manufactured by the laboratory Pfizer be administered oral (in tablets). The recipe is ready at the first sign of infection covid to avoid serious forms. It is available since February 2022 In Francein pharmaciesOn April 25, the High Authority for Health (HAS) spoke out in favor of refund of this treatment. The Paxlovid Features contraindications before taking it. This drug treatment comes in addition to vaccination not “as a substitute”. What is the composition Paxlovi? Which indication? Its effectiveness against Covid? what is being price The side effects?

What is Paxloved?

Photo of a box of Paxlovid © Ministry of Health

The American pharmaceutical company Pfizer developed antiviral treatment, marketed under the name Paxlovíd is made from nirmatrelvir and from ritonavir† It comes in the form of tablets to be taken as soon as possible after the positive diagnosis for Covid-19 and maximum within 5 days after the onset of symptoms. This treatment targets the enzyme needed for viral replication, the 3C-like protease, and by inhibiting its action, it blocks SARS-CoV-2 replication in the body. She was granted a Marketing Authorization (AMM) on January 28, 2022.

What are the indications for Paxlovid against Covid?

Treatment with Paxlovid is reserved for people who are at risk for severe forms of Covid-19. It must be started in 5 days after the onset of Covid symptoms. To be eligible, the patient must meet all of the following criteria:

  • Be at least 18 years old
  • Having a positive SARS-CoV-2 test (RT-PCR or antigen)
  • Appearance of first symptoms attributable to COVID-19 disease < 5 days
  • Patient not requiring oxygen therapy due to COVID-19
  • Patient at high risk of progression to severe form of COVID-191
  • No contraindication for treatment
  • Risk of drug interactions assessed and treatment initiation deemed possible by the prescriber
  • Patient clearly informed about the procedures for carrying out this treatment

How to get Paxlovid in pharmacies?

The Paxlovid is the first treatment for Covid-19 available in city pharmacies. It can be prescribed by general practitioners ever since February 3, 2022. Public pharmacies in the city on presentation of the prescription stating the barcode with which the pharmacist can check whether the prescribing doctor has validated the suitability of the treatment. The order is placed by the pharmacist after delivery of the prescription by the patient. Therefore, in order to take delivery times into account and to respect the taking of the medicine within 5 days of the appearance of symptoms, it is necessary that the patient goes to the community pharmacist quickly after the medical consultation and the starting symptoms.

How effective is it against Covid and against Omicron?

According to the High Authority of Health, Paxlovid “retains antiviral activity on the different variants“The data available to assess the efficacy of this treatment have shown that reducing the risk of progression to a severe form of Covid-19 (admission or death) by approximately 85.2% after his reign.” In addition, Paxlovid’s mechanism of action gives hope for continued efficacy on its various variants, including Omicron. Preliminary in vitro data indeed suggest that the variants of concern currently in circulation are amenable to treatment.

What is the composition of Paxlovid?

Paxlovid consists of two molecules:

► The first PF-07321332 is the active agent that prevents the virus protein from multiplying.

► The second is ritonavira protease inhibitor, normally used to treat HIV infections. †HIV is not related to coronaviruses and the replication of the genetic material occurs through a different mechanism. But it produces him too a poly-protein that needs to be cut 9 times each a protease to form new viral particles’, explains an article published in June 2020 in the scientific journal Medicine Science.

Paxlovid would prevent the coronavirus protease from replicating.

A protease is a virus-specific enzyme which acts on viral proteins to promote virus replication† Therefore, in order to stop the replication of a virus, it is necessary to reduce or prevent the action of the protease. Coronaviruses have two proteases, one of which is named SARS-CoV-2, 3CL† It is on this protease that the oral treatment Paxlovid works.

What is the dosage of Paxlovid?

The recommended dosage for PAXLOVID® is: 300mg PF-07321332 (2 tablets of 150 mg) and 100mg ritonavir (1 tablet of 100 mg), to be taken together (3 tablets in totaloral, 2 times a day for 5 days† PAXLOVID can be taken with or without food. The tablets should be swallowed whole and should not be chewed, broken or crushed. It should be administered as soon as possible after obtaining a positive result in a direct virological screening test for SARS-CoV-2 (PCR or TAG) and at the latest within 5 days of the onset of symptoms.

What are the side effects of Paxlovid?

Of the patients enrolled in the Pfizer study published in November 2021 who received Paxlovid, 1.7% had serious side effects and had to stop treatment. Indeed, the active ingredient in this drug, ritonavir, can cause side effects such as:

  • diarrhea,
  • nausea and vomiting
  • stomach ache
  • sore throat or cough,
  • headache and dizziness
  • rash and itching
  • disorders in the metabolism of sugars and fats with abnormal redistribution of fat observed after several months of treatment (called lipodystrophy
  • toxicity to the liver (increase in transaminases) and the pancreas.

What are the contraindications of Paxlovid?

The antiviral agent is contraindicated in people with severe hepatic impairment or severe renal impairment (eGFR < 30 ml/min), including patients with end-stage renal disease on hemodialysis. Dose adjustment is necessary in patients with moderate renal impairment. Furthermore, it is not the use of Paxlovid during pregnancy and in women of childbearing potential not using contraception is not recommended. Breast-feeding should be discontinued during treatment with PAXLOVID® and, as a precaution, for 7 days after the end of treatment. The use of ritonavir may reduce the effectiveness of combined hormonal contraceptives. Patients using combined hormonal contraceptives should be advised to use an effective alternative method of contraception or an additional “barrier” method of contraception during treatment with PAXLOVID® and until the menstrual cycle after discontinuation of PAXLOVID®

What is the price of Paxlovid?

The price of the Paxlovid pill is unknown. Nevertheless, Pfizer announced in its press release that tiered prices based on each country’s income level to ensure equitable access for all and an affordable price. In other words, high- and upper-middle-income countries will pay more than low-income countries. The specialty PAXLOVID® (PF-07321332 150 mg/ritonavir 100 mg film-coated tablets) is distributed free health facilities and pharmacies. The user therefore benefits from this with full support.

Will Paxlovid be reimbursed?

On April 25, the HAS voted in favor of reimbursement of this treatment. †It confirms the progress made by this drug by awarding it a Level 3 Improvement of True Benefit (ASMR). Registration for reimbursement of this treatment should facilitate the prescribing of Paxlovid® in public medicine and thus its access for patients. In addition, GPs can rely on the Rapid Responses published by the HAS to prescribe this drug” specifies the authority in a press release.

sources

– Covid-19: granted early access to Paxlovid® as a curative treatment. HAS. Press release 21 January 2022.

– PFIZER’S NOVEL COVID-19 ORAL ANTIVIRAL TREATMENT CANDIDATE REDUCED HOSPITAL OR DEATH RISK BY 89% IN INTERIM ANALYSIS OF PHASE 2/3 EPIC-HR STUDY, November 5, 2021.

– Targeting the key protease of SARS-CoV-2 to produce an effective drug against this coronavirus, Medicine Science, June 2020.

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