Hi Aimeth,
I think it is only understandable that your husband has depressive episodes. My husband suffered from depression for about 40 years and medication can help stabelize him, but it may also cause side effects. Everyone reacts different,so it is very hard to say what the side effects will be. Therefore, I am not sure if you want to add another medication to the ones he already takes. Did you try to talk to him and discuss his depression?
Also the suggestion of Stephany to contact Cancer Centre for psychological therapy is very good advice.
As you wrote before it is a recurrence of the cancer and the prognosis was not too great. If I remember correctly the chemo is MVAC, the "mother of all chemos" as Wendy wrote, "... and not easy to take". The recurrence, the prognosis, the hard time he has with chemo have of course an effect on him mentally.
It may be good to talk about it, which isn't easy, but it may help to clarify things and make it more understandable for all parties.
Take care,
Renee