"Serious Mass" weight gain + Acne antibiotics

Ok I know this gets asked a lot but I'm yet to see a well put together answer.

I'm taking "Tetralysal 300 (lymecycline)" which is an antibiotic for Acne, with a course lasting around 6 months (I'm on my 6 month now and my doctor has prescbribed it for another 2 atleast)

It states on the box that I should avoid Milk and medicines containing Zinc and Iron (It says in the instructions "Moderate levels of milk should not effect the absorbtion of Tetralysal" and to "Wait atleast 2 hours after taking the medication before eating or taking remedies containing Zinc or Iron.

Problem is my weight gain shake contains all of what I'm told to avoid

I spoke to my doctor about taking protein at the same time as the medication and she wasn't even aware I was to avoid dairy/zinc/iron.... infact her response was "I didn't know you have to avoid them.... if it says to avoid it on the box avoid it" but in reality all I want to know is can I take them at different times of the day? if not.... why not?

Any answers based on experience would be great!

Thanks!

Lymecycline is from a group of antibiotics called the tetracyclines. The problem is that one of their characteristics is to bind to metal ions in your diet, such as zinc and calcium, which inactivates them. Hence you're advised against zinc/calcium supplements or consuming zinc/calcium rich foods within 2 hours of taking them).

what weight gain shake do you take? I'm looking to put on weight (really badly I've got 1 stone in 3 months due to stress)