A rest from herceptin

Hi everyone After my heart function coming up and not down, I had treatment with herceptin and the ok for another four doses, then I see the oncologist and hopefully have the last dose in November. Now I have another question I hope someone maybe able to help with. I have been on Arimidex but my foot which I have pins in and hands have been aching so he decided to put me on tamoxifen 20mg per day. It is apparently his favourite drug as it has been tried and proven to be effective. As soon as I took it, I had a huge thirst and felt weary and light headed. Saw my chemist who suggested I take it at night, to see if I felt better. It does seem to help, but interested in others that may have had Similar side effects. Bye now Jill