| Irinotecan Metabolism Pathway |  | Drug Metabolism | ATP / Irinotecan / Mesoheme / Uridine-5'-Diphosphate / SN-38 |
| Irinotecan Topoisomerase Inhibitor Action Pathway |  | Drug Action | Irinotecan / Uridine-5'-Diphosphate / SN-38 |
| Iron sucrose Drug Metabolism |  | Metabolic | Iron sucrose |
| Isavuconazole Action Pathway |  | Drug Action | Formic acid / Mesoheme / Ergosterol / Isavuconazole |
| Isavuconazonium Action Pathway |  | Drug Action | Formic acid / Mesoheme / Ergosterol / Isavuconazonium |
| Isobutyryl-CoA Dehydrogenase Deficiency |  | Disease | Pyridoxal phosphate / Biotin / Succinic acid / Glutamic acid / Pyridoxal / Leucine / NADH / Valine / Isoleucine / ATP / Acetoacetic acid / Oxogluric acid / Flavin adenine dinucleotide / alpha-Ketoisocaproic acid / alpha-Ketoisovalerate / Methylmalonic Acid |
| Isobutyryl-CoA Dehydrogenase Deficiency |  | Disease | Pyridoxal phosphate / Biotin / Succinic acid / Glutamic acid / Pyridoxal / Leucine / NADH / Valine / Isoleucine / ATP / Acetoacetic acid / Oxogluric acid / Flavin adenine dinucleotide / alpha-Ketoisocaproic acid / alpha-Ketoisovalerate / Methylmalonic Acid |
| Isocarboxazid Amine Oxidase Norepinephrine Antidepressant Action Pathway |  | Drug Action | Pyridoxal phosphate / Ademetionine / Ascorbic acid / Tyrosine / NADH / Sapropterin / Norepinephrine / Dopamine / Levodopa / Isocarboxazid / Magnesium cation / Iron / Flavin adenine dinucleotide / Pyrroloquinoline Quinone |
| Isocarboxazid Amine Oxidase Serotonin Antidepressant Action Pathway |  | Drug Action | Pyridoxal phosphate / Tryptophan / Sapropterin / Isocarboxazid / Calcium / Iron / Oxitriptan / Flavin adenine dinucleotide |
| Isoconazole Action Pathway |  | Drug Action | Formic acid / Mesoheme / Ergosterol / Isoconazole |
| Isoetharine Action Pathway |  | Drug Action | ATP / Isoetharine / Potassium cation / Calcium / Magnesium cation / Cyclic adenosine monophosphate |
| Isoetharine Predicted Metabolism Pathway |  | Metabolic | Isoetharine / Mesoheme |
| Isoeugenol Predicted Metabolism Pathway |  | Metabolic | Mesoheme / Isoeugenol |
| Isoflurane GABA(A) Anesthetic Action Pathway |  | Drug Action | Pyridoxal phosphate / Glutamic acid / ATP / Isoflurane / Calcium / Magnesium cation / Cyclic adenosine monophosphate / gamma-Aminobutyric acid / Pyrophosphoric acid |
| Isoflurophate Action Pathway (new) |  | Drug Action | Choline / Isoflurophate / Calcium / Magnesium cation / Acetylcholine / Acetic acid |
| Isoflurophate Drug Metabolism |  | Metabolic | Isoflurophate |
| Isometheptene Predicted Metabolism Pathway |  | Metabolic | Mesoheme / Isometheptene |
| Isoniazid Action Pathway |  | Drug Action | Sapropterin / Isoniazid / Mesoheme / Flavin adenine dinucleotide / Flavin mononucleotide |
| Isoniazid Drug Metabolism |  | Metabolic | Isoniazid |
| Isoniazid Metabolism |  | Metabolic | Pyruvic acid / Glutathione / Glycine / Isoniazid / Calcium / Mesoheme / Oxogluric acid |
| Isoprenaline Action Pathway |  | Drug Action | ATP / Isoprenaline / Potassium cation / Calcium |
| Isoprenaline B1-Adrenergic Cardiac Muscle Contraction Action Pathway |  | Drug Action | ATP / Isoprenaline / Calcium |
| Isopropamide Predicted Metabolism Pathway |  | Metabolic | Isopropamide / Mesoheme |
| Isosorbide Dinitrate Action Pathway |  | Drug Action | Nitric Oxide / Isosorbide dinitrate / Potassium cation / Calcium / Magnesium cation / Flavin adenine dinucleotide / Pyrophosphoric acid |
| Isosorbide dinitrate Drug Metabolism |  | Metabolic | Isosorbide dinitrate |