Can a different brand of Citalopram be affecting me so badly...

I wondered if anyone could help me out.

I have suffered from anxiety for 5 years and have only recently broken down and gone to my doctors after years of trying to cope and deal with it myself.
My doctors has put me on 10mg of Citalopram and Positive Mental Training tracks which i listen to one track for a week, once a day. The tracks really are working and i find my body going into relaxed mode as soon as i recognize the attacks starting. After 4 weeks of this i went back to my doctors for a follow up and to get the next CD for my tracks. She re-prescribed me on 10mg as they seemed to be working and i work full time and therefore don't want to mess that up with a higher dose.
After starting to take this course my body seems completely off. After taking my tablet my body instantly need to go the toilet where i have diarrhoea. This was 6days ago and every day since i have been suffering. I took my tablet this morning and haven't been able to eat anything yet my guts are completely upside down. My first batch of Citalopram was by a company called Sendoz and these ones are by Teva. I thought it might be an ingredients difference but upon checking they are both the same apart from Teva is coated.

I wondered if anyone else has experienced this sort of thing and how they coped with it? I had to take Imodum because it has gotten so bad after 6 days. I thought it was just a side affect but now i am thinking its the coating on the tablets. Will i be able to explain and get them exchanged for the Sendoz brand i was on? I simply can not continue suffering worse then my life was with the anxiety at full blown scale.

Any advice would be grateful.

Do you know what the coating on the tablets is ?

I had similar problems with venlafaxine, was on effexor for years and then changed to another that caused me to have indigestion. Nobody believed me that they were causing me problems as apparently the 'active ingredients are identical'. I then change to another brand (as it happens TEVA) and they were fine, no problems.

So, I for one do believe that slight changes in 'carrier ingredients' can cause problems....

Just to add, if your diahorrea is that bad then you simply must return to the doc and explain as you can't carry on like this ! The reason why you have been given the TEVA brand is because it is a cheaper alternative to the named brand. You will need to ask the GP to stipulate on the prescription a specific brand that you need.

Can i not go the pharmacy where i got them with my prescription and ask to exchange them?

You can try, but I suspect they will say you need a new prescription.

You will need a new perscription .Pharmacys dont take drugs back .It is common to get an upset stomach for a while when you start on these type of meds .Some contain a form of natural sweetner that can cause bad reactions in some people .Maybe the new brand contains this ..The drug element isnt the cause tho .T/c Sue