- Food and Drug Administration www.fda.gov
- American Academy of Clinical Toxicology www.clintox.org
- CDC Guideline for Prescribing Opioids for Chronic Pain www.cdc.gov
- Toxicology Data Network www.toxnet.nlm.nih.gov
- Pharmacology Corner www.pharmacologycorner.com
- ToxTutor – US Department of Health & Human Services www.toxtutor.nlm.nih.gov