| HIMP | high-dose intravenous methylprednisolone |
|---|---|
| IDU | idoxuridine; injection or intravenous drug user; iododeoxyuridine |
| IGIV | immune globulin intravenous |
| IGTT | intravenous glucose tolerance test |
| IHT | insulin hypoglycemia test; intravenous histamine test; ipsilateral head turning |