MACROLIDES

The prototype is erythromycin (1950), but newer agents include carithromycin (Biaxin) and Azithromycin (Zithromax). Zithromax is the common tx for H. pylori ulcers, and both biaxin and zithromax are potent p450 inhibitors. They have narrow gram positive coverage, and there is moderate resistance to the macrolide antibiotics. The allergtic potential is low, and they can be used in pts allergic to other antibiotics. Contraindications for erythromycin include hypersensitivity to any macrolide antibiotic. Special problems encountered with the macrolides include many drug interactions due to the action on hepatic drug metabolism. Nausea, vomiting, abdominal pain; rarely pseudomembranous colitis.


Generic name Proprietary name

Erythromycin base E-mycin, Ilotycin, Ery-Tab, Robimycin, RP-Mycin,

Eryc Ilosone

Erythromycin estolate Ilosone

Erythromycin stearate Ethril, Wyamycin-S, Pfizer-E, Erypar, Eramycin,

Bristamycin, SK-Erythromycin

Erythromycin ethylsuccinate E.E.S., Pediamycin, E-Mycin E, EryPed,

Wyamycin-E

As you can see, when prescribing an erythromycin you need to be specific which one you want, because there are many different brandnames. Commonly, “eryc-” in the brand name lets you know its an erythromycin.


Seldane (an H-1 blocker) when combined with erythromycin results in death because the p450 system is severely inhibited. Seldane has been pulled from the market.

Category: Pharmacology Notes