According to reports from many domestic media on December 13, many Internet medicine platforms have begun or are about to open up the sales of COVID-19 oral medicine in the combined packaging of Nematovir/Litonavir tablets (Paxlovid) developed by Pfizer. Patients can only upload nucleic acid or antigen positive certificates and be diagnosed with COVID-19 infection to issue prescriptions for online purchase at a price of nearly 3000 yuan per box. However, the relevant platforms later denied the above information, and the pre-sale information could not be found in their applications and web pages. Pfizer COVID-19 medicine, can you take it when it's really positive? There are many restrictions on drug use. Watch out for side effects. First of all, Paxlovid is only approved by the U.S. Food and Drug Administration (FDA) for the treatment of COVID-19 infected people over 12 years old, with mild to moderate symptoms, and with a high risk of disease deterioration. In China and Europe, it is only approved to treat adults with mild to moderate COVID-19 accompanied by severe high-risk factors. In other words, the drug is not suitable for people with low risk of severe diseases, such as young people without basic diseases and vaccinated. At the same time, the EPIC-HR (evaluation of protease inhibition of COVID-19 in high-risk patients) study released by Pfizer pointed out that the drug has a wide range of drug contraindications. Paxlovid is a powerful CYP3A inhibitor, and CYP3A is a very important drug metabolizing enzyme in human body. More than 50% of clinical drugs are metabolized by CYP3A. Therefore, taking Paxlovid or significantly increasing the concentration of CYP3A metabolic drugs in human blood may cause very serious side effects. According to Paxlovid's instructions, the drug is forbidden to use with the commonly used drugs for the treatment of hypertension and benign prostatic hyperplasia, such as alfazosin, ranolazine, amiodarone, dronedarone, flucarnet, propafenone, quinidine, colchicine, the cardiovascular drugs epridone, ivabradine, the commonly used lipid-lowering drugs lovastatin, simvastatin, and the migraine drugs eletroptan, And dozens of drugs such as sildenafil are used together, otherwise it may cause serious or even life-threatening reactions. At the same time, some commonly used drugs, such as warfarin, digoxin, clarithromycin and erythromycin, need to closely monitor the blood drug concentration or adjust the dose when used with Paxlovid. Israel is one of the first countries in the world to approve the use of Paxlovid. According to the medical guidelines issued by Clalit, the largest medical service organization in Israel, Paxlovid is only used for the elderly or "high-risk groups" suffering from certain diseases. Before using the drug, patients must report their medical history to doctors or pharmacists, especially allergies, liver and kidney diseases, as well as any other drugs they are taking, including dietary supplements and herbs, Do not take any new drugs without informing your doctor. The drug effect may not be obvious for young people, but more effective for the elderly. In September this year, the Clalit research team published a paper in the New England Journal of Medicine. According to the relevant data provided by the team, from January 9 to March 31, 2022