Senior cat losing weight after switching to feeding times

[Rebecksa]

Hello,

I have a 16 year old cat that's always been free fed, and about 11 lbs since she's been an adult cat. She always portioned herself and exercised well enough, since she's gotten older she gets less exercise, sleeps more and eats less but it all balanced out.

She went to the vet October 2013 and was 10.8lbs still, I got a kitten about a month ago and had to switch them to feeding times since the kitten has to eat kitten food, and my older cat is on Fibre Response.

I took my older cat (Ebenee) to the vet May 29th for a check up, they said she's healthy and everything is sounding normal, except she's down to 10lbs and gave me mirtazapine to try her on, it's supposed to make her more hungry. All it did was make her meow non stop the first day, and yes she was more hungry, but never for more food at feeding time, she wanted to eat more frequently. I already feed her 4 times a day, I work during the day so I can't feed her more than that many times. I gave her two pills 4 days apart, but without me home to feed her more times in the day it wasn't doing anything, so I stopped that.

It's June 21, and now she's down to 9.2lbs. I'm going to call the vet on Monday to see what I can do. Just wanted to check here to see if anyone had any experience with this. Any advice?