Visitors are often advised to have vaccinations prior to departing for China; your government's website will list the recommendations currently in force.
China has strict rules on the import of medicines and not all drugs commonly prescribed to westerners will be readily available. You are allowed to bring small amounts of prescription drugs into the country in your personal baggage. You should bring a copy of your prescription with you as customs officers may need to check it.
Chinese medicine is of course popular and Chinese remedies are readily available from the many stores in the city.