Erythromycin

Overview

The original macrolide antibiotic. Due to its short half-life, severe GI toxicity, and massive drug interactions, it is largely obsolete as an antibiotic. Now heavily utilized as an IV prokinetic to force gastric emptying.

Maximum Dose

Max 4 g/day.

Clinical Focus

Like Clarithromycin, it is a potent CYP3A4 inhibitor. Causes agonizing stomach cramps by massively stimulating gut motilin receptors.

Bottom Line

Erythromycin is a macrolide useful for respiratory infections and as a prokinetic agent, but causes significant GI disturbance and has extensive CYP3A4 drug interactions.

Brand Names

Eryc, EES

Oral Routes

Capsules/Tablets (250 mg, 400 mg).

Parenteral

Vials (1 g powder) for IV infusion.

Prescribing & PBS

Unrestricted General Benefit (S4).

Primary

Penicillin-allergic patients with susceptible infections.

Off-Label

Gastroparesis, clearing blood from the stomach prior to an urgent endoscopy for a GI bleed.

Clinical Place

Almost entirely replaced by Azithromycin and Clarithromycin for infections. Survives in hospitals entirely as a GI motility agent.