Erythromycin; Uses, Dosage, Side Effects, Drug Interactions

Erythromycin is a bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. Insensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.

It inhibits bacterial protein synthesis by binding to bacterial 50S ribosomal subunits; binding inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins. Erythromycin may be bacteriostatic or bactericidal depending on the organism and drug concentration.

Mechanism of Action of Erythromycin 

Erythromycin acts by penetrating the bacterial cell membrane and reversibly binding to the 50 S subunit of bacterial ribosomes or near the “P” or donor site so that binding of tRNA (transfer RNA) to the donor site is blocked. Translocation of peptides from the “A” or acceptor site to the “P” or donor site is prevented, and subsequent protein synthesis is inhibited. Erythromycin is effective only against actively dividing organisms. The exact mechanism by which erythmromycin reduces lesions of acne vulgaris? is not fully known: however, the effect appears to be due in part to the antibacterial activity of the drug.

Indications of Erythromycin 

• Acne vulgaris
• Bacterial infections
• Upper respiratory tract infection
• Dental abscess
• Bacterial endocarditis? prevention
• Skin or soft tissue infection
• Bartonellosis
• Bowel preparation
• Bronchitis?
• Bullous pemphigoid
• Campylobacter gastroenteritis?
• Legionella pneumonia?
• Lymphogranuloma venereum
• Mycoplasma pneumonia
• Nongonococcal urethritis
• Ocular rosacea
• Otitis media
• Pemphigoid
• Pertussis
• Pharyngitis
• Pneumonia
• Rheumatic fever prophylaxis
• Strep throat
• Chlamydial ophthalmia neonatorum
• Community acquired pneumonia
• Gastroparesis
• Granuloma inguinale
• Intestinal amebiasis caused by entamoeba histolytica
• Legionella pneumophila infections
• Lower respiratory tract infection
• Lymphogranuloma venereum
• Ophthalmia neonatorum (gonococcal)
• Postoperative Infections
• Primary syphilis
• Staphylococcal skin Infections
• Ureaplasma urethritis
• Skin and subcutaneous tissue bacterial infections caused by streptococcus pyogenes
• Superficial ocular infections

Contra-Indications of Erythromycin 

• Clostridium difficile infection
• Myasthenia gravis
• Hearing loss
• Very rapid heartbeat – torsades de Pointes
• prolonged QT interval on EKG
• Abnormal EKG with QT changes from birth
• Liver? problems
• Abnormal liver function tests
• Inflammation? of the liver with stoppage of bile flow

Dosage? of Erythromycin 

Campylobacter Gastroenteritis

• Mild? to moderate? infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe? infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Chancroid

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Lymphogranuloma Venereum

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Mycoplasma Pneumonia

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Mycoplasma Pneumonia

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Nongonococcal Urethritis

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Otitis Media

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.

Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

 Pharyngitis

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Pneumonia

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Soft Tissue Infection

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Syphilis – Early

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Upper Respiratory Tract Infection

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Bronchitis

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Chlamydia Infection

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Lyme Disease

• Mild to moderate infection: 250 to 500 mg (base, estolate, stearate) or 400 to 800 mg (ethylsuccinate) orally every 6 hours.
• Severe infection: 1 to 4 g/day IV in divided doses every 6 hours or by continuous infusion.

Legionella Pneumonia

• Although the dosage has not been established, clinical? trials have used 1 to 4 g/day orally or IV in divided doses every 6 hours or by continuous infusion.

Pediatric Bacterial Endocarditis

• 20 mg/kg (ethylsuccinate or stearate) orally two hours before the procedure, then one-half the amount six hours after initial dose.

Side Effects of Erythromycin 

The most common

• nausea, vomiting,
• allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
• sweating
• skin color change, mild diarrhea
• mild nausea
• loss of appetite
• vaginal discharge and itching
• swelling of feet or legs
• chest pain
• constipation
• cough
• diarrhea or loose stools
• difficulty with breathing
• dizziness
• heartburn

More common

• Abdominal or stomach pain, discomfort, or tenderness?
• chills or fever
• difficulty with moving
• headache, severe and throbbing
• joint or back pain
• muscle aching or cramping
• muscle pains or stiffness
• chest pressure or squeezing pain in chest
• excessive sweating
• feeling of heaviness, pain, warmth and/or swelling in a leg or in the pelvis?
• sudden tingling or coldness in an arm or leg
• sudden slow or difficult speech
• sudden drowsiness or need to sleep
• fast breathing
• sharp pain when taking a deep breath
• fast or slow heartbeat
• coughing up blood
• rust colored urine
• decreased amount of urine

Rare

• Anxiety
• change in vision
• seizures
• abnormal or fast heart rate?
• tremors
• weight loss
• chest pain or tightness
• confusion
• cough
• Agitation
• arm, back, or jaw pain?
• blurred vision
• chest pain or discomfort
• convulsions
• extra heartbeats
• fainting?
• hallucinations
• headache
• irritability

Drug interactions of Erythromycin 

Erythromycin may interact with following drugs,supplements & may change the efficacy of drugs

• alprazolam
• atorvastatin
• azithromycin
• azole antifungal agents (e.g., ketoconazole, itraconazole, fluconazole, posaconazole)
• bromazepam
• carbamazepine
• clindamycin
• clobazam
• clonazepam
• clopidogrel
• corticosteroids (e.g., methylprednisolone, prednisone, dexamethasone)
• cyclosporine
• diltiazem
• felodipine
• fexofenadine
• flurazepam
• levofloxacin
• lovastatin
• moxifloxacin
• phenytoin
• phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
• quetiapine
• risperidone
• salmeterol
• simvastatin
• sotalol
• SSRIs (e.g., citalopram, fluoxetine, paroxetine, sertraline)
• telithromycin
• theophylline derivatives (e.g., theophylline, aminophylline, oxtriphylline)
• tricyclic antidepressants (e.g., amitriptyline, nortriptyline)
• trimipramine
• valproic acid
• verapamil
• warfarin

Pregnancy & Lactation

FDA pregnancy category B

Pregnancy