the term 'rapid weight gain'......until it happened to me and this was when I was put on Lyrica (much higher dose than yours)....... However I don't know that I can put the entire blame on that particular med, as I was also put on others and was dealing with Hypothyroid in that same timeframe.

But, what scared me the most about the 'rapid' weight gain (as in 9 pounds in one month!) was becoming short of breath and the high blood pressure that went along with it. This was downright SCARY! It seemed like it became out of my 'control' and I wasn't really eating much at all!

It was a Neurologist who put me on this 'instant' high dose cocktail of Lyrica, Amitriptyline.....and whatever else I was taking at the time (can't recollect)....it just ended up being a very bad 'mix' for me and the confusing condition/symptoms I was facing.
Obviously too much too soon....

This was a few years ago and I've since lost the weight and won't ever go on that high a dose ever again....... I do take a very low dose of Neurontin (Lyrica's cousin) and seem to be ok.

You 'know' your body. If you notice what seems to be 'rapid' weight gain....I'd certainly not put off keeping it in check, cuz it can get out of control, fast.
And yes, the liver enzymes shot up too.

Wishing you the best
Rae