Key takeaways
Gentak (gentamicin) and erythromycin eye ointment are both antibiotics used to treat bacterial eye infections, but they belong to different classes. Gentak (gentamicin) is an aminoglycoside antibiotic that kills bacteria by blocking their ability to make proteins necessary for their protective covering. In contrast, erythromycin is a macrolide antibiotic that stops bacteria from growing by preventing them from making essential proteins. Gentak is available in both eye drop and ointment forms, while erythromycin is only available as an ointment. Gentak is typically used 2 to 3 times a day, whereas erythromycin may need to be applied up to 6 times a day. Erythromycin is also used to prevent pink eye in newborns exposed to certain STIs during birth, a use not indicated for Gentak. Both medications require a prescription and can cause temporary eye irritation or blurry vision.
