- Ibandronate
- Ibogaine
- Ibrutinib
- Ibuprofen
- Ibutilide
- Ibuzatrelvir
- Icatibant
- Icotinib
- Idarubicin
- Idebenone
- Idelalisib
- Ifosfamide
- Iguratimod
- Ilaprazole
- Iloperidone
- Iloprost
- Imatinib
- Imeglimin
- Imidacloprid
- Imidapril
- Imidocarb Dipropionate
- Iminostilbene
- Imipenem
- Imipramine
- Imiquimod
- Indacaterol
- Indapamide
- Indigo Carmine
- Indinavir
- Indocyanine Green
- Indomethacin
- Indoramin
- Infigratinib
- Ingenol
- Inosine
- Inositol
- Intermedine
- Iobitridol
- Iodixanol
- Iohexol
- Iopromide
- Ioversol
- Ipamorelin
- Ipragliflozin
- Ipratropium
- Iptacopan
- Irbesartan
- Irganox
- Irinotecan
- Isavuconazole
- Iscotrizinol
- Isoconazole
- Isocycloseram
- Isoflurane
- Isomalt
- Isomaltitol
- Isometheptane
- Isoniazid
- Isoprenaline
- Isopropyl Palmitate
- Isoproterenol
- Isopulegol
- Isosorbide Dinitrate
- Isosorbide Mononitrate
- Isosulfan Blue
- Isothipendyl
- Isotretinoin
- Isoxsuprine
- Isradipine
- Istradefylline
- Itopride
- Itraconazole
- Ivabradine
- Ivacaftor
- Ivermectin
- Ivosidenib
- Ixabepilone
- Ixazomib
- Izuforant