Erythromycin: Uses, side effects & precautions!

Erythromycin is a macrolide antibiotic used in bacterial infections. It is similar in action to azithromycin.


  • Upper respiratory tract infections
  • Pneumonia
  • Influenza
  • Listeriosis
  • Whooping cough
  • Diphtheria
  • Erythrasma
  • Intestinal amebiasis
  • Acute PID
  • Chlamydia
  • Syphilis
  • Legionnaires’ Disease
  • Prevention & management of rheumatic fever.


Dosage forms:

  • Tablet: 250 mg, 500 mg
  • Capsules: 250 mg, 500 mg
  • Granules for suspension: 200 mg/5 ml
  • IV solution: 500 mg
  • Ointment:  0.5%

Dosage guidelines: 

  • In amebiasis: 250 mg tablet twice a day for 10 days.
  • Diphtheria: 15 to 20 mg/kg IV per day over 20-60 mins, twice a day for 10 days.
  • Ear infection: 250 mg tablet/capsule twice a day for 10 days.

Missed dose: Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

a) Gastric lavage & induction of vomiting
b) Dialysis & hydration therapy.


  • Nausea & vomiting ,
  • Confusion,
  • Loss of appetite ,
  • Fever & weakness
  • Abdominal pain
  • Dehydration & diarrhea
  • Pus or mucus in stool,
  • Racing heartbeat, chest pain & palpitations
  • Dizziness & fainting
  • Cold sweats,
  • Swelling of the lips, eyelids and inside the throat,
  • Joint pain,
  • Sudden rash appearing on the palms of the hands, soles of the feet and face
  • Skin peeling without blistering.


  • Arrhythmia
  • QT prolongation
  • Convulsions
  • Reversible hearing loss
  • Pancreatitis
  • Steven-Johnson Syndrome
  • Colitis
  • Jauntice
  • Abnormal liver enzyme level
  • Injection site phlebitis
  • Intestinal nephritis
  • Rhabdomylosis
  • Anaphylactic shock.


Erythromycin is contraindicated and precaution is advised in patients with following conditions:

  • Impaired liver function
  • Hepatitis
  • Myasthenia gravis
  • Hypersensitivity to macrolide antibiotics
  • Cardiovascular problems
  • Patients taking anti-arrhythmic drugs
  • Pregnancy
  • Infants
  • Patients receiving anti-psychotic therapy.


  • Erythromycin when given in presence of theophylline can lead to increased serum levels of the latter & subsequent toxicity.
  • Elevated levels of digoxin are found when given in presence of Erythromycin.
  • Increased anticoagulant effect occurs when anticoagulant drugs are given concomitantly with erythromycin.
  • The drug inhibits the CYP3A enzyme system, therefore the drugs that are metabolized by this enzyme system may not be properly metabolized.
  • When used in presence with ergotamine, acute toxicity of ergotamine occurs.
  • Erythromycin reduces the clearance rate of some benzodiazepines and therefore elevated levels and effect of these benzodiazepine drugs is seen.
  • The drug increases concentrations of HMG-CoA reductase inhibitors (e.g., lovastatin and simvastatin).
  • Systemic concentration of sildenafil increases in presence of erythromycin.


  • Pregnancy: It is a pregnancy category B drug and therefore is safe for use in pregnant women.
  • Breast Feeding: The drug passes into the breast milk and therefore caution should be advised.
  • Children: The drug should not be given to children below 8 years due to potential risks of liver damage.