The majority of medications should not be taken when breastfeeding. Insufficient Milk Syndrome effects a small percentage of mothers. These women cannot produce enough milk for their child. Also working mothers may find breastfeeding too much of a hassle. Bottlefeeding could be a mothers choice because it will give her more freedom, and time.
Family members are able to feed the baby.
You can also see exactly how much the baby is consuming. The disadvantages are the time it takes to sterilize and prepare the bottles, and the cost of formula. I myself have breastfed, and bottlefed. Only the mother can decide what the right option is. Regardless of your choice the baby will need to be burped periodically between feedings.