Unless you abused opiates in the past or have side effects you probably want to take them for the first few days. Your not going to be driving and need to rest, so if you reason is I need to do stuff your not going to do much while drains are in.
My doctor gave me Percocet and Celebrex (expensive $30 with coupon). They afterwards realized that I needed Valium due to muscle spasms. The Percocet and Valium suck be cause it make my memory fuzzy. I stopped taking them during the day, but I still need the Valium at night for painful muscle spams. The Celebrex reduces swelling, so that is why she prescribed that. Also Ibuprofen she said was not allowed due to it's effect on blood thinning.
Sleep is a wonder drug, so yeah if you can't sleep your body won't be able to rest and repair. The pain wasn't that bad after my drains were out. Walking afterwards wasn't painful, but you have to get use to the shift in center of gravity. The compression things on you legs suck and my mom is a nurse, so I walked at least 1/4 mile to appease her as they would bunch up in my knee crease.