There is a study being done to try to bring together the findings of many existing experiments which have tested the medication used to “prevent” MAV.
The researchers appear to be doing their best to exclude any bias and make their findings as objective as possible (not easy in my opinion as it is very hard to objectively measure MAV!)
Here’s the link:
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010600/full
Hopefully the results will appear soon.
Sparks