- I-Hyoscyamine
- Ibuprofen
- Ibutilide
- Idarubicin
- Idoxuridine
- Imipenem-Cilastatin Sodium
- Imipramine
- Immune Globulin, Hepatitis B
- Immune Globulin Intramuscular
- Immune Globulin Intravenous
- Immune Globulin, Rabies
- Immune Globulin, Tetanus
- Immune Globulin, Varicella-Zoster (Human)
- Indapamide
- Indigo Carmine
- Indinavir
- Indomethacin
- Insulin
- Interferon Alfa
- Interferon Beta-1B
- Interferon Gamma-1B
- Iocetamic Acid
- Iodamide
- Iodinated Glycerol
- Iodine
- Iodipamide
- Iodoquinol
- Iodothyrin
- Iodoxamate
- Iopanoic Acid
- Iothalamate
- Ipodate
- Ipratropium
- Iprindole
- Iproniazid
- Irbesartan
- Isocarboxazid
- Isoetharine
- Isoflurophate
- Isometheptene
- Isoniazid
- Isopropamide
- Isoproterenol
- Isosorbide
- Isosorbide Dinitrate
- Isosorbide Mononitrate
- Isotretinoin
- Isoxsuprine
- Isradipine
- Itraconazole
