Erythromycin cyclocarbonate (Davercin) is a first generation semi-synthetic erythromycin. It is active against Gram-positive and some Gram-negative microorganisms. Davercin shows comparable or better in vitro potency, low host toxicity and improved pharmacokinetics compared with erythromycin. It is approved for the treatment of acne, atypical pneumonia (caused by Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila), whooping cough (treatment and prevention), urethritis (caused by Ureaplasma urealyticum and Chlamydia trachomatis), gastrointestinal infection caused by Campylobacter spp., short-term infections of the skin and soft tissues (e.g. acne, staphylococcal dermatitis). In streptococcal infections, diphtheria, gonorrhea, early syphilis in patients who are allergic to penicillin, and in the prevention of bacterial endocarditis before the planned dental procedures. Adverse effects are: nausea, vomiting, abdominal pain, diarrhea, skin allergic reactions.

Berythromycin or erythromycin B (also known as 12-deoxyerythromycin A), an acid-stable co-metabolite of the antibiotic erythromycin A, exhibits broad-spectrum antibiotic activity. The antibacterial activity of erythromycin B is similar to that of erythromycin A, but after acid-treatment, resembling exposure to the stomach, erythromycin B substantially retains antibacterial activity, whereas erythromycin A does not. Erythromycin B played an integral part of the structure activity relationship studies of semi-synthetic erythromycins.

Pseudoerythromycin A enol ether is devoid of antibiotic activity but can be used as an analytical standard for erythromycin A stability studies.

Erythromycin Oxime is the major metabolite of Roxithromycin which is also an intermediate of Azithromycin. It exhibits antibacterial properties and is also Roxithromycin impurity C.

Erythromycin cyclocarbonate (Davercin) is a first generation semi-synthetic erythromycin. It is active against Gram-positive and some Gram-negative microorganisms. Davercin shows comparable or better in vitro potency, low host toxicity and improved pharmacokinetics compared with erythromycin. It is approved for the treatment of acne, atypical pneumonia (caused by Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila), whooping cough (treatment and prevention), urethritis (caused by Ureaplasma urealyticum and Chlamydia trachomatis), gastrointestinal infection caused by Campylobacter spp., short-term infections of the skin and soft tissues (e.g. acne, staphylococcal dermatitis). In streptococcal infections, diphtheria, gonorrhea, early syphilis in patients who are allergic to penicillin, and in the prevention of bacterial endocarditis before the planned dental procedures. Adverse effects are: nausea, vomiting, abdominal pain, diarrhea, skin allergic reactions.