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Emetine looks like a potent antiviral in vivo for coxsackievirus B, echovirus and cytomegalovirus

Hip

Senior Member
Messages
17,976
Emetine looks like a potent antiviral for coxsackievirus B, echovirus and cytomegalovirus.

Emetine is one of the main alkaloids found in the roots of the ipecacuanha plant.

Emetine EC50 values for CVB, echovirus and CMV are very low, around the 0.05 μM mark (see table 1 of this study). This is what makes emetine a potent antiviral at low doses.

Emetine EC50 Values for Various Viruses

Cytomegalovirus
EC50 = 0.04 μM.
Echovirus 1 EC50 = 0.14 μM.
Echovirus 6 EC50 = 0.045 μM.
Coxsackievirus A16 EC50 = 0.083 μM.
Coxsackievirus B1 EC50 = 0.05 μM.
SARS-CoV-2 EC50 = 0.50 μM.
Zika virus EC50 = 0.053 μM
Ebola virus EC50 = 0.017 μM
HIV EC50 = 0.03 μM
Source: table 1 of this study.

The emetine EC50 for Zika virus is also around 0.05 μM, and emetine was demonstrated in this study to reduce Zika viral loads in mice by 10 times, which is a major reduction. This was achieved at safe dose levels: the mice were given 1 mg/kg of emetine by injection daily; this is equivalent of a human dose of 0.08 mg/kg, which works out at around 6 mg for an adult human, which is considered safe (see toxicity section below).

So since emetine works for Zika virus in vivo, it should also work for coxsackievirus B, echovirus and cytomegalovirus in vivo, as all these viruses have more or less the same EC50 of around 0.05 μM.

It's not often that you find an antiviral that can target a range of ME/CFS viruses like CVB, echovirus and CMV.

Emetine also has some efficacy against SARS-CoV-2, but it is about 10 times weaker for SARS-CoV-2 compared to CVB, echovirus and CMV, as the SARS-CoV-2 EC50 is 10 times higher at 0.50 μM.



Emetine Sources

Emetine is incredibly cheap, costing about $5 for a kilogram on IndiaMart.

Emetine is found in syrup of ipecac, with 30 ml of the syrup providing emetine 13.8 mg and cephaeline 45 mg.

In India, a safer synthetic analogue of emetine called dehydroemetine is available as an injection called Tilemetin. But it is not known if dehydroemetine has the same antiviral effects as emetine. Ref: 1. It is safe as it has a lower cardiovascular risk.

Tilemetin is cheap, costing about $0.50 for a 60 mg injection. One such injection vial could provide 10 x 6 mg oral doses.

EDIT: one study examining the antiviral effects of emetine and dehydroemetine on SARS-CoV-2 found both have similar antiviral potency, but with dehydroemetine, only one of its four isomers (named the (-)-R,S isomer) worked as an antiviral; the other three isomers of dehydroemetine did not have any antiviral action. So may be best to use emetine, because we don't know which dehydroemetine isomer is present in the Tilemetin injections.



Emetine Administration and Toxicity

High doses of emetine (20 to 60 mg daily) can be toxic to the nerves, the heart, and can also cause nausea. But low doses of 6 mg daily are considered safe and do not create nausea, according to the "Toxicity of Emetine in Clinical Practice" section of this paper.

This paper (full text on SciHub) delves more deeply into the cardiotoxic effects of emetine. I have not yet fully examined this study.

This paper says that when a 30 ml oral dose of ipecac syrup (containing 13.9 mg of emetine) was administered to 10 people, all these people vomited, due to the nausea effect. So if oral doses are taken, these need to be low. Note though that ipecac syrup also contains cephaeline, which is more nausea-producing than emetine.

If any nausea does occur with emetine, it can be treated with 5-HT3 antagonists such as ondansetron. Ref: 1 Lemon essential oil 5 or 10 drops is also a good 5-HT3 antagonist.

Unfortunately when emetine is injected, it causes pain at the injection site which can last hours or days. This pain is experienced in both subcutaneous and intramuscular injections, and for low and high doses of emetine.

So oral dosing may be better. Though one issue with oral dosing is that "emetine absorption from oral ipecac displays considerable inter-patient variation. Some patients may not absorb sufficient emetine or alkaloids to be therapeutically effective". Ref: 1



Emetine Pharmacokinetics

Emetine has a half-life of 35 hours.

In tests in mice, rats and dogs, it was found that emetine concentrations in the tissues were relatively low, but the drug was found at very high concentrations in the tissues. Ref: 1. This may be appropriate for ME/CFS, because in ME/CFS the viral infections are found in the tissues, not so much the blood.
 
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Hip

Senior Member
Messages
17,976
Here are some issues I found with emetine, regarding its toxicity to the heart: This paper, in the full text on SciHub, it says:
Six deaths were described as occuring after a total of only 0.6 grams, but the majority followed 1.2 grams.

The paper later says:
The total dose of emetine should not exceed 0.6 grams in any one course; at least two months should elapse between courses of treatment in patients who show any electrocardiographic changes

So it looks like you should never go over a total of 600 mg of emetine total accumulative dose. That equates to a 100 days on 6 mg daily.

It seems that it is the total accumulative dose that counts regarding heart damage, and the more emetine you take in total, the higher the chances of heart damage.

This presents a problem, because with ME/CFS, if any antiviral works, it is likely you will need to take that antiviral indefinitely, in order to keep the virus supressed. But if you take emetine indefinitely, you accumulated dose will get higher and higher, so there is a risk that heart damage might appear.


Short courses of were emetine used by 10s of millions of people up until the 1970s to treat amoebiasis (infection with the amoeba Entamoeba histolytica). They would typically get 60 mg daily for 7 days for amoebiasis.

For antiviral purposes, 6 mg daily should work. But in the long run, your total accumulated dose will build up, and so there is the potential for heart damage.
 

Hip

Senior Member
Messages
17,976
Considering all this, is it worth trying for EV?

Unfortunately I think emetine will be too toxic to the heart for ME/CFS purposes.

This is because for treating ME/CFS, you would need to take any antiviral for months and probably indefinitely for it to have effect. And it's when you take emetine for a long time that you get heart toxicity, from the total accumulated amount ingested.


You might like to look into salidroside (from the herb Rhodiola rosea) as an alternative enterovirus antiviral.
 
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Messages
97
Could emetine be used for short treatment periodes in combination with other anti EV drugs to reduce viral loads. Lets say for 1 or 2 weeks at 6mg?

https://www.mdpi.com/1999-4915/12/10/1178

For example emetine in combination with vemurafinib seems to have synergetic effects on EV. Plus you reduce the chances of drug resistance and you can lower the dose of each drug when taken in combination.

But it seems quite hard to get emetine...
You might like to look into salidroside (from the herb Rhodiola rosea) as an alternative enterovirus antiviral.
This looks promising as well!
 

Hip

Senior Member
Messages
17,976
Could emetine be used for short treatment periodes in combination with other anti EV drugs to reduce viral loads. Lets say for 1 or 2 weeks at 6mg?

My guess is that you might possibly make some gains in health with a short course of emetine, but you might lose those gains within weeks or months of stopping. This is often the case when using antivirals to treat ME/CFS.

Also, we don't know that emetine is safe even for short treatment periods. You may not die from a short course of treatment, but it's possible that some subclinical heart damage might still occur.

If we knew that a short course of emetine could cure ME/CFS, it might be worth taking that risk, as emetine was given to millions of people in a short course to treat amoebiasis. But usually with antivirals in ME/CFS, there is relapse if you stop them. Though with Valcyte and tenofovir, some patients have reported permanent gains that were maintained even after stopping, after a year long course of these drugs.



I've looked into hundreds of antiviral substances for enteroviruses (listed in this post) and other ME/CFS viruses, but almost all don't work out for some reason or other.
 

Cipher

Administrator
Messages
1,001
EDIT: one study examining the antiviral effects of emetine and dehydroemetine on SARS-CoV-2 found both have similar antiviral potency, but with dehydroemetine, only one of its four isomers (named the (-)-R,S isomer) worked as an antiviral; the other three isomers of dehydroemetine did not have any antiviral action. So may be best to use emetine, because we don't know which dehydroemetine isomer is present in the Tilemetin injections.
It seems like the clinical formulations of dehydroemetine contain both the (-)-R,S isomer and other isomers. In this supplementary material to the paper you linked the following can be read:

DHE4
An active ingredient of the clinical formulation of dehydroemetine. Also known as 2,3 (-) dehydroemetine or dehydroemetine
DHE2 OR DHE3
1S, 11bS dehydroisoemetine (DHE2 OR DHE3) is considered as an inactive component of the dehydroemetine sample used in clinic against amebiasis

This old paper from 1968 says that:
The dehydroemetine available for clinical use is a synthetic racemic mixture consisting of equal proportions of the laevorotatory (- ) and dextrorotatory ( +) enantiomers.

I also found this study indicating that dehydroemetine is antiviral in humans (against VZV), and not only in vitro:
A study involving forty patients, all sixty years of age or over, compared the use of dehydroemetine in twenty and triamcinolone in twenty for the treatment of herpes zoster. Pretreatment evolution was less than ten days. Patients treated with dehydroemetine did not experience postherpetic neuralgia, and in fourteen pain completely disappeared at the end of only one series of treatment, which in four patients consisted of only three injections. Postherpetic neuralgia developed in only eight patients out of those treated with triamcinolone, and in four pain persisted for more than six months. The results of laboratory tests, including cardiovascular evaluation, remained normal with both drugs.
There's also this paper on the same topic but there's no online abstract available.
 
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