Every person on earth right now is praying for one treatment that can cure Covid-19 completely and not just reduce the severity of symptoms in moderate cases. Even the vaccines are not completely effective and your risk of suffering from a severe disease if you are immuno-compromised is still there.
Out of so many clinical trials conducted on the efficacy of various drugs to treat covid-19 patients, only a handful can be effective in some scenarios. Dexamethasone and tocilizumab are 2 drugs that are used by the majority of hospitals for treating patients who require supplemental oxygen due to treating respiratory failure secondary to covid-19 pneumonia.
N-acetylcysteine or NAC long is another potential candidate that is currently under study in the search for finding the therapeutic modality that can stop the progression of the covid-19 disease. SM pharmaceutical in Bangkok sells Fluimucil which contains Acetylcysteine, the drug that has the potential to reduce symptoms of covid-19.
Mechanism of action of N-Acetylcysteine
In severe cases of covid-19 pneumonia, many inflammatory markers such as IL-6 and CRP increase many folds. This is associated with low blood levels of hydrogen sulfide.
Hydrogen sulfide is supposed to be a defense factor that our body uses against SARS-CoV-2 viral infection. When the levels of hydrogen sulfide become low, the prognosis of recovering from a severe disease dramatically becomes poor.
NAC or N-acetylcysteine administration can produce the following actions in treating covid-19 infections:
- Therapeutically increasing hydrogen sulfide production endogenously.
- Providing L-cysteine to replenish the intracellular pool of glutathione which is essential for restoring the redox state.
- Exhibiting mucolytic effect and thus lowering the viscosity of the mucus.
- Blocking angiotensin II production to reduce the severity of pulmonary disease caused by covid-19 infection.
SARS-CoV-2 has an E protein with a triple cysteine motif that interacts with an S protein terminal motif by disulfide bonds. Since NAC can cleave the disulfide bond. This can prevent these motifs from interacting and reduce the rate of infectivity of the virus.
Clinical trials on NAC till now are done on very small groups and thus, the results remain inconclusive. However, larger studies are going to determine the effect of N-acetylcysteine on reducing the infection severity in covid-19 patients.
NAC can be given in a nebulized form, as an oral drug, or through IV administration. In patients who are on a ventilator to treat respiratory failure, nebulized N-acetylcysteine can be combined with heparin to reduce the need for ventilation. At the dose of 6g per day, it can be administered via IV route to hospitalized covid-19 patients to reduce the need for critical care.
It can also be used as a preventive therapy at an oral dose of 600 mg per day in people who are at high risk of exposure to the SARS-CoV-2 virus.
The scale and length of clinical studies need to be increased to get strong evidence about the ability of NAC therapy in reducing the severity of covid-19 infections in patients. Other drugs are simultaneously under trials to find one effective solution that can give us some relief from the pandemic and the stress of a closed one succumbing to the disease.
