It wouldn't be unreasonable to suspect that smoking methamphetamine, one of the most widespread and damaging illicit drugs, would lead to enhanced susceptibility to various respiratory pathogens, such as influenza. That's what Chen et al had in mind when they set out to see whether meth had such an effect on influenza replication in cell culture; after all, it's already associated with enhanced susceptibility to other pathogens such as HIV and HCV (due to biological, as well as behavioural, factors). It seems this may not be the case. The study used levels of meth which are likely to be found in meth users blood, so in that sense it's realistic. When they tried infecting cells pre-treated with meth with influenza A virus, whilst the virus was able to replicate, it didn't reach the levels of control cells which hadn't been treated with meth. Similarly, when they looked for the expression of viral proteins in infected cells, they found that, as the concentration of meth increased, the level of viral protein decreased, further showing that meth is detrimental to influenza replication in this system.
|Treating cells with increasing amounts of meth resulted in a does dependent reduction in the expression of the viral proteins M1 and NS1.|
So how does meth affect the influenza virus lifecycle? Treating the virus with meth and then infecting untreated cells didn't make a difference to the number or size of the plaques which were formed, suggesting that meth doesn't affect the ability of the virus particles to infect and replicate in the cells. Therefore it's presumably downstream of entry; extrapolating to a human, meth therefore might not prevent the chances of becoming infected. Indeed, the study found the inhibitory effects to occur during the actual replication. Interestingly, the inhibitory effect doesn't appear to be significantly linked to enhancing the interferon response.
|Treating influenza virus with meth didn't alter the development or size of plaques|
This all leads to the tongue in cheek suggestion that if you catch influenza then smoking a bit of crystal meth may help treat the infection. Perhaps it does, and it will be intriguing to see whether the method of action can be determined and therefore less damaging drugs discovered, but that would not justify consuming meth, one of the most ravaging and repulsive drugs around. For a start, one of the stark realities about this paper is that it is using cultured cells, which doesn't really mimic the complexity of the respiratory tract. Then there are the effects of the drug: enhanced susceptibility to other pathogens, addiction, depression, heart disease, anxiety, 'meth mouth', altered heart and breathing rates, diahorrea, constipation, insomnia, hallucinations etc. etc.........
......anyone fancy a cohort study???
Chen, Y., Wu, K., & Chen, C. (2012). Methamphetamine Reduces Human Influenza A Virus Replication PLoS ONE, 7 (11) DOI: 10.1371/journal.pone.0048335