Erythromycin and its Medical uses

Erythromycin is an antibiotic used to treat a variety of bacterial infections.This includes respiratory infections, skin infections, chlamydia, pelvic inflammatory disease, and syphilis.It may also be used during pregnancy to prevent group B strep infection in newborns,and to improve delayed gastric emptying.It can be administered intravenously and orally.Eye ointment is often recommended after delivery to prevent eye infections in newborns.Common side effects include abdominal cramps, vomiting, and diarrhea.More serious side effects may include Clostridium difficile colitis, liver problems, QT prolongation, and allergic reactions.It is generally safe in people who are allergic to penicillin.Erythromycin also appears to be safe to use during pregnancy.Although breastfeeding is generally considered safe, the use of breast milk by mothers during the first two weeks of life may increase the risk of pyloric stenosis in infants.This risk also applies if administered directly to infants of this age.It belongs to the class of macrolide antibiotics and works by reducing the production of bacterial proteins.

Erythromycin was first isolated from Saccharopolyspora in 1952It is on the World Health Organization’s list of essential medicines.In 2020, it was the 225th most commonly prescribed drug in the United States with over 2 million prescriptions.

Medical uses

Erythromycin is used to treat bacteria that cause skin and upper respiratory tract infections, including Streptococcus, Staphylococcus, Haemophilus, and Corynebacterium. The following are MIC susceptibility data for some bacteria of medical interest:

• Haemophilus influenzae: 0.015 to 256 micrograms/ml

• Staphylococcus aureus: 0.023 to 1024 micrograms/ml

• Streptococcus pyogenes: 0.004 to 256 micrograms/ml

• Minimal Corynebacteria: 0.015 to 64 μg/ml

Because of this boost, it may help treat gastroparesis.It has been shown to improve feeding intolerance in critically ill patients.Intravenous erythromycin is also used during endoscopy to aid in the removal of gastric contents.

Available forms

Erythromycin is available in enteric-coated tablets, sustained-release capsules, oral suspensions, eye drops, ointments, gels, enteric-coated capsules, non-enteric-coated tablets, non-enteric-coated capsules and injections.The following erythromycin combinations are available in oral dosages:

• Erythromycin base (capsules, tablets)

• Erythromycin acetate (capsules, oral suspension, tablets), contraindicated during pregnancy

• Erythromycin ethyl succinate (oral suspension, tablet)

• Erythromycin stearate (oral suspension, tablet)

For injections, available combinations are: 

• Erythromycin Glucose

• Erythromycin lactobionate

For ophthalmology:

• Erythromycin base (ointment)

Side effects

Gastrointestinal disturbances, such as diarrhea, nausea, abdominal pain, and vomiting, are very common because erythromycin is a motilin agonist.Because of this, erythromycin is often not listed as a first-line drug.More serious side effects include cardiac arrhythmias with QT prolongation, including torsades de pointes and reversible deafness.Anaphylaxis can range from hives to anaphylaxis. Cholestasis, Stevens-Johnson syndrome, and toxic epidermal necrolysis are some other rare side effects that may occur.Studies have shown evidence for and against the association of pyloric stenosis with prenatal and postnatal erythromycin exposure.Exposure to erythromycin (especially long-term antibacterial doses, and through breastfeeding) is associated with an increased likelihood of pyloric stenosis in young infants.Erythromycin in small infants with feeding intolerance not associated with hypertrophic pyloric stenosis.Erythromycin acetate has been associated with reversible hepatotoxicity in pregnant women, manifested by elevated serum glutamate-oxaloacetate transaminase, so its use during pregnancy is not recommended. Some evidence suggests similar hepatotoxicity in other populations.It can also affect the central nervous system, causing psychotic reactions, nightmares and night sweats.