Drug Profile

1. PRESENTED BY
DR. ASHFAQ AFRIDI
Erythromycin

2. Introduction
Class: Erythromycin is an intermediate spectrum
macrolide antibiotic
Obtained from: Streptomyces erythreus in 1952.
Structure: It contains two deoxy sugars attached to a
14 atom macrocyclic lactone ring
 Chemical formula: C37H67NO13
Molecular weight : 773.93 g/ mol

3. Chemical Structure

5. Indications
For susceptible microbiological entities in:
Bone and Joint infections
Lower respiratory tract infection (i.e. pneumonia,
bronchitis etc.)
GI infections
Otitis
Prevention of pharyngitis
Usually preferred as alternative to the patient having
penicillin hypersensitivity
As a pro-kinetic in gastroparesis

6. Dosage
Depending on the condition, doses of erythromycin
tend to range from the following:
250 milligrams (mg) to 500 mg, every six to 12 hours
500 mg every 12 hours
333 mg every eight hours
Adults: 250mg q.i.d for 10 days, max 4g/d
Children: 30-50mg/kg/d for 10 days, max 4g/d

7. Side Effects
Otto-toxicity resulting in hearing loss
Tinnitus
Hypersensitivity reactions leading to urticaria &
rashes
Steven Johnson syndrome
QT interval prolongation.
Nephrotoxicity (some time leads to kidney failure in
chronic use)
NVD
Cholestatic Jaundice

8. Pharmacodynamics
The antibacterial action of erythromycin and other
macrolides may be inhibitory or bactericidal (in high
concentration) for susceptible organisms
It blocks 50s Ribosomal RNA (Large sub unit of
ribosome).
Thus prevent protein synthesis

9. Pharmacokinetics
Basic in nature
Destroyed by stomach acid
Metabolized by CYP-3-A-4
Hepato-biliary secretion is the main process
 About 95 % drug is eliminated via this route
5% via urine

10. ContraIndications
Contraindicated in case of hypersensitivity to
macrolide antibiotics
Warning & Precautions:
 Use with caution in patients with
 liver and kidney disease, prolonged QT interval
 Take on empty stomach
Pregnancy: Category B

11. Interactions
Statins
Rifampin
Al & Mg containing Antacids
Oral anticoagulants
Astemizole
Benzodiazepines
Carbamazepine
Cyclosporin
Digoxin

12. THANKS