United States Pharmacopoeia (USP) regulations,the cotton and desiccant must be discarded , or they will adsorb moisture due to become a major source of pollution within the bottles of medicine, but easy to make drugs wet deterioration.

Should I throw away desiccant?

Simply dispose of the desiccant with your normal trash. According to the Code of Federal Regulations, desiccant is a non-combustible waste, unless it is lime-based. Dispose of lime desiccant in a place with no water present to prevent the possibility of fire.

Should I leave the desiccant in the bottle?

The desiccant packs are used to keep the tablets moisture-free. Once opened, they might attract moisture and stick together which may alter its molecule or spoil it. You can keep the packs inside, there is no harm in it. It will just keep the tablets dry.