This is some advice for people who are concerned about getting different brands whenever they collect their prescription. I know that some people can be sensitive to changes in supplier. Earlier today I was speaking to my sister (who works for Boots the chemist) about my anxiety. One of the things I mentioned was that my local (independent) pharmacy keeps changing the citalopram brand every couple of months or so. Sometimes I find this unsettling as I worry about whether the new brand will be as good as the old one.
She said that at Boots they always stick to the same supplier (Almus) unless there is a shortage, and this applies to all their stores. So I may well switch to Boots when I get my new prescription and see how I get on with the Almus brand. She said it is mainly the independent pharmacies (like the one I usually go to) that keep changing suppliers every couple of months in order to get the best deal, but if you go to one of the larger chains you are more likely to get the same brand every time. This is because the larger chains have special deals with specific suppliers so they don't keep chopping and changing.
I'd assume the same would apply to any medication, not just citalopram.