Most Infections

• PO (Adults): Base, stearate — 250 mg every 6 hr, or 333 mg every 8 hr, or 500 mg every 12 hr. Ethylsuccinate — 400 mg every 6 hr or 800 mg every 12 hr.
• PO (Children >1 mo): Base and ethylsuccinate — 30–50 mg/kg/day divided every 6–8 hr (max = 2 g/day as base or 3.2 g/day as ethylsuccinate). Stearate — 30–50 mg/kg/day divided every 6 hr (max = 2 g/day).
• PO (Neonates): Ethylsuccinate — 20–50 mg/kg/day divided every 6–12 hr.
• IV (Adults): 250–500 mg (up to 1 g) every 6 hr.
• IV (Children >1 mo): 15–50 mg/kg/day divided every 6 hr (max = 4 g/day).

Acne

• Topical (Adults and Children >12 yr): 2% gel, solution, or pledgets twice daily.

erythromycin base: E-Mycin

erythromycin ethylsuccinate: E.E.S, EryPed

erythromycin lactobionate: Erythrocin

erythromycin stearate: Erythrocin Stearate

erythromycin (Topical): Erygel

• Suppresses protein synthesis at the level of the 50S bacterial ribosome.

• Bacteriostatic action against susceptible bacteria.

Spectrum:

• Active against many gram-positive cocci, including:
  • Streptococci,
  • Staphylococci.
• Gram-positive bacilli, including:
  • Clostridioides,
  • Corynebacterium.
• Several gram-negative pathogens, notably:
  • Neisseria,
  • Legionella pneumophila.
• Mycoplasma and Chlamydia are also usually susceptible.

Therapeutic Classification: anti-infectives

Pharmacologic Classification: macrolides

Absorption: Variable absorption from the duodenum after oral administration (dependent on salt form). Absorption of enteric-coated products is delayed. Minimal absorption may follow topical or ophthalmic use.

Distribution: Widely distributed. Minimal CNS penetration. Crosses placenta; enters breast milk.

Protein Binding: 70–80%.

Metabolism/Excretion: Partially metabolized by the liver, excreted mainly unchanged in the bile; small amounts excreted unchanged in the urine.

Half-life: Neonates: 2.1 hr; Adults: 1.4–2 hr.

erythromycin base: Eryc

erythromycin stearate: Erythro-S

(blood levels)

• Instruct patient to take medication around the clock and to finish the drug completely as directed, even if feeling better. Take missed doses as soon as remembered, with remaining doses evenly spaced throughout day. Advise patient that sharing of this medication may be dangerous.
• May cause nausea, vomiting, diarrhea, or stomach cramps; notify health care professional if these effects persist or if severe abdominal pain, yellow discoloration of the skin or eyes, darkened urine, pale stools, or unusual tiredness develops. May cause infantile hypertrophic pyloric stenosis in infants; notify health care professional if vomiting and irritability occur.
• Caution patient to notify health care professional if fever and diarrhea occur, especially if stool contains blood, pus, or mucus. Advise patient not to treat diarrhea without consulting health care professional. May occur up to several wk after discontinuation of medication.
• Advise patient to report signs of superinfection (black, furry overgrowth on the tongue; vaginal itching or discharge; loose or foul-smelling stools).
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected, or if breast feeding.
• Instruct patient to notify health care professional if symptoms do not improve.

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