You can find published accounts of the adverse effects of drugs using a combination of MeSH Terms and Subheadings.
The most relevant Subheading is adverse effects, which includes two narrower terms, poisoning and toxicity. Each of these have their own definition in MeSH.
For additional information on using Subheadings, review the Module 2 section on Subheadings.
For an in-depth review (with practice exercises) of how to search PubMed for adverse effects of drugs, complete the Drug and Chemical Information – On Demand: Exploring New Drug Research class.