Sickness after chemo

Hi,
I don’t have Hebrew on my computer by you can reply in Hebrew – Thank you.
My father has squamous NSCLC, stage 4 and started his chemo treatment with carboplatin and Gemcitabine last Sunday. He started feeling sick and was vomiting last night.
The oncologist prescribed him some antiemetic medications:
Dexamethasone,Cetron,Bramin ,Lorivan but did not explain how to take them. Should he take them all together, only one at the time, before and after chemo,only when he feels sick?What is the dosage?
Is the sickness likely to continue over the next chemotherapy treatments? How long does it usually last?
I also heard about Emend – is it much better than the above drugs for preventing nausea?
Thanks a lot for your reply in advance.