Erythromycin and gastroparesis?  Off-licence use: uncertain efficacy for a poorly defined disorder.
(1) Erythromycin is sometimes used, without a licensed indication, for the treatment of gastroparesis by the oral or intravenous route.  (2) Scintigraphic studies have shown that intravenous erythromycin accelerates gastric emptying, especially in diabetic patients and during the postoperative period when emptying is slowed.  (3) No trials of acceptable quality have demonstrated any clear efficacy in the postoperative period.  (4) In the other settings the clinical assessment of erythromycin is only just starting.  There are no long-term trials or reliable comparisons with other prokinetic agents.  (5) Erythromycin can give rise to many drug interactions, some of which (especially torsades de pointes) can have severe consequences.
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D048909:Diabetes Complications; D004341:Drug Evaluation; D004348:Drug Labeling; D004917:Erythromycin / Q000627:therapeutic use*; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D018589:Gastroparesis / Q000188:drug therapy*; D006801:Humans; D011183:Postoperative Complications; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D005765:Gastrointestinal Agents; D004917:Erythromycin