was released to the public, widespread infections occurred across the country. When a large number of people are infected, the treatment of critically ill patients, especially how to prevent high-risk groups from developing critical illness and reduce the incidence and mortality of critical illness, has become one of the important issues that need to be solved in this "post-epidemic" era.
If you want to fight against the virus , drugs are an indispensable and important part. Although the new crown epidemic has been around for three years, there are only a few drugs that are truly targeted against the new coronavirus. Except for some monoclonal antibody drugs for people with low immunity, there are even fewer oral drugs with anti-new crown effects. Among the few drugs, hui The anti-COVID-19 drug nematvir/ritonavir tablets (Paxlovid) of Swiss Pharmaceutical Co., Ltd. can be regarded as a drug with more prominent effects. Today, it is reported on the Internet that Beijing has also begun to distribute Pfizer’s anti-COVID-19 oral drug to community health service centers. Its purpose is also an important measure to reduce the aggravation of high-risk patients. Is this drug useful? What are the precautions for using the drug? In today’s popular science article, let’s talk about this topic with you.
How does anti- new coronavirus "Special Drug" Paxlovid fight against the new coronavirus
Different from our commonly used single drugs and compound drugs, Paxlovid is a drug combination Form, this medicine contains two drugs, nematvir and ritonavir . The two drugs are packaged separately and taken together. The dosage of each dose is nematvir 300mg (2 tablets) and ritonavir 100mg (1 tablet). Take it twice a day, and a course of treatment is 5 days.
Two of the drugs are antiviral drugs, but ritonavir is an anti-HIV drug and has almost no effect on the new coronavirus. The "main drug" that mainly plays an anti-new coronavirus effect is nematvir. This drug is a 3CL protease inhibitor. 3CL protease is the main protease in the virus's own code that cuts and processes RNA. Therefore, for RNA viruses such as the new coronavirus, inhibiting the activity of the 3CL protease can inhibit the replication of the new coronavirus and achieve antiviral effects.
Then why should we take ritonavir? Ritonavir is also an antiviral drug, but in this drug combination, its main function is a "synergistic" effect. This drug is a powerful liver drug enzyme CYP3A4 inhibitor. By inhibiting the activity of liver drug enzymes, it can increase the blood concentration of another antiviral drug, nematvir, when it is metabolized in the human body, so that it can remain in the human body for a longer time at a higher concentration, thereby achieving better antiviral effects.
Simply put, nematvir has an anti-COVID-19 effect, but it requires high concentration and long-term retention in the body to achieve a good effect. Ritonavir helps it achieve this. The combination of the two drugs has a more efficient anti-viral effect.
In terms of its mechanism of action, this drug has an anti-coronavirus effect, but can everyone use it, and what are the precautions for using it? It is important to understand the following three aspects of knowledge.
Paxlovid is not available to everyone.
If we look at the instructions for the drug, the instructions for Paxlovid indicate that this drug is mainly used for people over 12 years old, for people with mild or common symptoms, and for people with a high risk of disease progression. The approved indications in my country are for the treatment of adult patients with moderate to severe COVID-19 infection who have high risk factors for developing severe disease.
In other words, for people infected with the new coronavirus, not everyone needs to take this drug. The main role of this drug is to prevent and reduce the risk of severe illness. In the face of Omicron variant, is this drug effective? Let's look at one of the largest clinical studies to date.
This study comes from Israel . The study period was from January 9 to March 31, 2022. The research target was people infected with the new coronavirus over the age of 40. At this time, the main strain in Israel was the early Omicron variant. During this period, more than 1.1 million people were infected with the new coronavirus, and 109,000 patients were considered high-risk, and 3,900 of them received Paxlovid treatment.
Two conclusions in the research results are very meaningful -
First, among people aged 40 to 64 years old, the odds of hospitalization due to new coronavirus infection between treated patients and untreated patients are very close (those who take medicine (15.2 cases/100,000 people, 15.8 cases/100,000 people without medication), indicating that the drug cannot reduce the risk of hospitalization in people over 65 years old, and in terms of death risk, the drug has not shown any significant effect..
Among people over 65 years old, the rate of hospitalization due to new coronavirus infection in treated patients was 14.7 cases per 100,000 people, while the rate of hospitalization for new coronavirus infection among people over 65 years old who did not receive Paxlovid treatment was 58.9 cases per 100,000 people. The risk of hospitalization was reduced by 73%, and the risk of death was reduced by 79% for people over 65 years old who received Paxlovid treatment. Real-world clinical studies such as
tell us that this drug should be effective against the Omicron variant in terms of its mechanism of action and clinical research results, and its main function is to protect high-risk infected people. Through the antiviral effect of the drug, it can reduce the replication of the virus in the human body, thereby reducing the risk of severe hospitalization and death. Especially for the elderly over 65 years old, most of them are at risk of severe illness. Therefore, if the risk situation can be assessed and drugs are applied in a timely manner, they can still be used to reduce the risk of severe illness and death.
The timing of drug selection is very important.
This is another point that needs attention, that is, the timing of drug administration. Paxlovid does not have a good antiviral effect throughout the entire course of the disease after infection with COVID-19. The best time to administer Paxlovid is to apply the drug within 5 days of the onset of the disease, especially when it does not develop into severe disease. For high-risk patients with severe disease, using the drug in the early symptomatic stage will have a better antiviral effect. And if the drug is used again when the patient has already developed into a critical illness, the effect will not be obvious, and the effect of the drug on improving the mortality rate of severe disease will be greatly reduced.
Therefore, we should treat the drug Paxlovid rationally. Its antiviral effect is to inhibit the replication of the virus. On the premise that the virus has not yet formed large-scale replication in the body, taking drugs to prevent severe disease may be useful. However, if the timing of medication is missed and the medication is taken too late, the effectiveness of the drug will not be that high.
Pay attention to the risk of drug interactions
Ritonavir in the Paxlovid drug combination is a powerful liver drug enzyme inhibitor. Although it plays a positive role in improving the anti-COVID-19 effect of nematvir, many drugs that may need to be used together are also metabolized by the liver drug enzyme CYP3A4. If you do not pay attention to drug interactions, taking these drugs with Paxlovid may bring about the risk of adverse reactions. Let me briefly share with you common drugs that should be used with caution and prohibited drugs during the use of Paxlovid -
- commonly used cardiovascular beta-blocker drugs, metoprolol, bisoprolol, carvedilol, etc., can be used together with confidence.
- Among antihypertensive drugs, valsartan , nifedipine , amlodipine , diltiazem, terazosin and other drugs should be used with caution. Try to stop or switch to other antihypertensive drugs while taking Paxlovid.
- Among the lipid-lowering drugs, simvastatin should be banned, atorvastatin and rosuvastatin should be used with caution, ezetimibe should be used with caution, and other statins and fibrates can be used together with confidence.
- Among antiplatelet and anticoagulant drugs, aspirin, dipyridamole , heparin , etc. can be used together with confidence, but warfarin should be used with caution, and rivaroxaban, clopidogrel , and ticagrelor have been banned.
- For sedative-hypnotic drugs, lorazepam can be used, while zopiclone and zolpidem should be used with caution, and estazolam, diazepam and other drugs should be banned.
- Commonly used drugs such as acarbose , metformin, insulin , linagliptin, sitagliptin, liraglutide , dapagliflozin , empagliflozin, glimepiride and other anti-diabetic drugs can be used together with confidence. Be careful when using pioglitazone and glibenclamide.
- Antipyretic and analgesic drugs, ibuprofen , diclofenac sodium , acetaminophen , and celecoxib can be used together with safety, while codeine, fentanyl, oxycodone, tramadol, etc. should be used with caution.
- Among the drugs that dilate the bronchus and improve cough and other problems, ipratropium bromide , salbutamol, olodaterol, montelukast and other drugs can be used together, but salmeterol should be banned.
- Gastrointestinal medications omeprazole , pantoprazole , rabeprazole , famotidine , and metoclopramide (metoclopramide) can be used together, loperamide should be used with caution, domperidone should be banned.
Having said so much, I believe everyone will have a deeper understanding of this drug. We don’t need to be overly mythical about the drug Paxlovid. Its main function is to inhibit the replication of the virus. In the early stages of the disease, there is a risk of severe illness, especially in the elderly group. It can reduce the risk of severe illness and death. In the process of taking the drug, there are also many precautions and drug contraindications. I would also like to appeal to everyone not to blindly believe in "special effects". With the current epidemic spreading on a large scale, it is also very important to concentrate superior resources on high-risk groups who need it more. #Where to buy Pfizer’s new crown oral medicine#
