Analysis of anti-FIP drugs with detected Molnupiravir content
We have received information that several Chinese drug manufacturers, in an effort to reduce the production costs of drugs and their sales price as much as possible while maintaining the largest possible margin, have started to use Molnupiravir (EIDD-2801) as an active ingredient.
The information came from the global group FIP Warriors 5.0, which published several analyzes of drugs declaring GS441524 or GC376 as the active ingredient, but the results of the analyzes show that the drugs contain the already mentioned Molnupiravir. You can see one of the analyzes below. If someone would object that analytics are some means of competitive struggle, it is not so. There were several independent analyses, we also know about the analysis from Bulgaria, one analysis also took place in Slovakia, but the one published by the global FIP Warriors group is the most complex.
Medicines in the CR/SR with the declared content of GS441524 containing EIDD-2801
This fact also affects our group. One of the drugs where the presence of EIDD-2801 was detected is the widely distributed Suyi brand. The fact that the medicine contains another active substance is not a problem for the person himself. The problem is that the manufacturer hid this fact and declared GS441524 as the active ingredient of their products. This fact should apply to "water" based injectable solutions, which do not sting when applied and whose pH is around 6.
It should be emphasized here that both EIDD2801 and GS441524 are very effective in the treatment of FIP. However, some specifics apply to their use. For example, they have different pharmacokinetics. The one with GS441524 allows application once every 24 hours, while Molnupiravir should be administered twice a day. Anyway, GS441524 is already a very well-proven drug with a minimum of side effects. EIDD-2801 has been used in the treatment of FIP for a shorter time and the official clinical trial is only ongoing, or has not yet been published. That is why other drug manufacturers have so far only recommended it for the treatment of relapses, or in case the cat does not respond to treatment with GS441524. In other words, the drug of first choice is still GS441524. On the other hand, precisely because of the policy of Gilead, which holds the patent for GS441524, hope has dawned for the official treatment of FIP with Molnupiravir, as it has been registered and approved for the treatment of Covid-19 in humans. As a result, a legally available drug (Lagevrio) also appeared in the Czech Republic, but its price was and still is very high and its availability for veterinary use is very complicated.
In an effort to ensure the cheapest possible medicines in order to save as many cats as possible, very cheap medicines also entered our market. The truth is that medication works. We also encountered versions of the solutions that really stung a lot, so it's quite possible that Suyi actually contained GS441524, but over time the manufacturer decided to arbitrarily change the active ingredient, but still declared that it supplied GS441524.
But Suyi is not the only drug containing EIDD-2801 available on our market, about which its manufacturer provided misleading information. In the "How we defeated FIP" group, the drugs from Figure 2 are used.
Why is information about the active substance important?
- GS441524 and Molnupiravir have a slightly different mechanism of action. GS441524 acts as a terminator of the viral RNA chain, thereby preventing the virus from replicating. EIDD-2801 integrates into the virus's genome, where it causes an accumulation of virus mutations known as a viral error catastrophe, rendering the virus unable to replicate.
- The pharmacokinetics of GS441524 allows application once a day, while EIDD-2801 in oral form should be applied twice a day according to current knowledge. Official information on the frequency of application of the injection form does not yet exist.
- GS441524 has already been used for several years in the treatment of FIP, several clinical trials, while the use of EIDFD-2801 in clinical practice is relatively new.
- The cytotoxicity of GS441424 is lower than that of EIDD-2801. However, it should be noted here that both substances are safe if the recommended dosage is not exceeded. However, if the dosage is significantly exceeded, side effects may appear in the form of significant neutropenia, drooping/dropped ears, etc.
- GS441524 was originally created for injection use, later a tablet form was added. EIDD-2801 was initially intended only for oral use (tablets), while the injectable form was never the subject of a clinical trial. It is only assumed that EIDD and GS have similar bioavailability limits as GS. This means that approximately 50% of the active substance is used for the tablet.
- There is a lack of information on the potential side effects of EIDD-2801 in the long term. Considering that the active substance - N4-hydroxycytidine - is a strong mutagen, it is not clear whether after 12 weeks of treatment, which is much longer than the recommended period of 5 days in human medicine, the side effects cannot manifest/accumulate more significantly way.
What is the impact of using another active substance to treat FIP?
- Pills
In principle, there is no problem with tablets, provided that the content of Molnupiravir corresponds to the stated content of GS. The dosage remains the same, we only recommend dividing the dose calculated for GS into 2x a day. This means, for example, that if you administered 1 tablet of Suyi once a day, you will administer 1/2 tablet twice a day. Actually, even with GS, it is recommended, especially with higher dosages, to administer the medication twice a day. - Injection solutions
With them, the situation is a bit more complicated, as the indicated concentration of 20mg/ml differs considerably from the measured one (Suyi 40mg/ml, while the real measured concentration of the second solution "Cat rehabilitation nutrition supplement" is up to 70mg/ml). Due to the relatively unclear dosage of EIDD in injectable form and the significantly higher concentration, we recommend not to overdo the dosage. The manufacturer Suyi rejects the accusation regarding the change of the active ingredient.
Previous experience with the use of Suyi medicines
Given that the manufacturer still claims that Suyi products contain GS441524, the drug was used and dosed as GS441524, including application only once a day. After more than 9 months, we can declare that its therapeutic effect is indisputable, we register a large number of cured cases, the price of the treatment is favorable, so it would probably be a hasty decision to stop recommending this medicine. However, due to the manufacturer's attitude, we cannot really guarantee the active ingredient in Suyi products. Again, I emphasize that both GS441524 and EIDD-2801 are effective in treating FIP, so it cannot be said that the drug itself is a scam. Of course, it would be better if the manufacturer, instead of ignoring the analyses, simply and clearly declared the active substance according to reality. Until that happens, it is important that you share your experiences with this medicine. For example, in the form of reviews on the website, or directly in the FIP Warriors CZ/SK group.
We certainly do not want to cause panic with this warning. The truth is that the drop in the price of treatment has made it available even for cases where their owners would otherwise have decided on euthanasia. However, in light of the above findings, it is up to you which medication you decide to use. In any case, pay extra attention to checking/monitoring the cat's condition.
Medicines with directly declared EIDD-2801 content
If the manufacturer openly produces drugs containing EIDD-2801, this is of course a good and serious approach. You can find some medicines containing EIDD-2801 here:
https://www.fipwarriors.eu/kategoria-produktu/molnupiravir/
More information about molnupiravir and the treatment of FIP using it
Treatment of 18 cats with FIP with molnupiravir: A case series
Antivirals and FIP treatment protocols
Tablets GS-441524 vs. Molnupiravir (EIDD-2801)
The role of molnupiravir in the treatment of cats with FIP in Australia
Alternative treatments for cats with FIP and natural or acquired resistance to GS-441524
EN 
SK
Unfair practices of some manufacturers of anti-FIP drugs
What about BasmiFIP? I am using BasmiFIP, is it a safe drug for FIP treatment?
https://www.basmifip.com/
As far as I know according to pictures it looks like CureFIP.