PCE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for PCE (PCE).

How it works

PCE (erythromycin) binds to the 50S subunit of bacterial ribosomes, inhibiting protein synthesis by blocking translocation of peptides.

What the body does with it

Metabolism	Primarily metabolized by the liver via demethylation; CYP3A4 is the major enzyme involved.
Excretion	Primarily renal (about 70-80% as unchanged drug and metabolites via glomerular filtration and tubular secretion); minor biliary/fecal elimination (10-15%).
Half-life	Terminal elimination half-life is approximately 3-5 hours in adults with normal renal function; may be prolonged to 7-10 hours in renal impairment (CrCl <30 mL/min).
Protein binding	Approximately 65-85% bound to serum albumin and alpha-1-acid glycoprotein.
Volume of Distribution	0.5-1.0 L/kg, indicating moderate tissue distribution (e.g., lungs, kidneys, liver); not extensively bound to erythrocytes.
Bioavailability	Oral immediate-release: 85-95% (due to first-pass metabolism, reduced to ~60-80% for extended-release); topical: 10-20% (systemic absorption).
Onset of Action	Oral immediate-release: 1-2 hours; intravenous: within 30 minutes; topical: 2-4 hours.
Duration of Action	Oral immediate-release: 6-8 hours; intravenous: 4-6 hours; topical: 8-12 hours depending on formulation.

Classification & Brands

Dosing & administration

Erythromycin ethylsuccinate (PCE) typical adult dose: 400 mg orally every 6 hours or 800 mg orally every 12 hours. Maximum 4 g/day.

Dosage form	TABLET, COATED PARTICLES
Renal impairment	No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (GFR <10 mL/min), consider dose reduction by 50% or extending interval to every 12 hours due to potential accumulation.
Liver impairment	Child-Pugh Class A: No adjustment. Class B: Reduce dose by 50% or extend interval. Class C: Avoid use; if necessary, reduce dose by 75% with close monitoring.
Pediatric use	Weight-based: 30-50 mg/kg/day in divided doses every 6-12 hours. Maximum 2 g/day.
Geriatric use	Use with caution due to increased risk of QT prolongation and hearing loss. Start at lower end of dosing range (e.g., 400 mg every 12 hours) and monitor renal function, electrolytes, and ECG.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for PCE (PCE).

Breastfeeding	Excreted in breast milk in low levels; M/P ratio not established. Considered compatible with breastfeeding by the American Academy of Pediatrics. Weigh benefits against potential risk of infant gastrointestinal disturbance or rash.
Teratogenic Risk	FDA Pregnancy Category B. First trimester: No evidence of teratogenicity in animal studies; human data limited but no increased risk of major malformations reported. Second and third trimesters: May cause transient neonatal neutropenia if used near term; no known structural anomalies.

Warnings & precautions

■ FDA Black Box Warning

Erythromycin may prolong the QT interval and cause torsade de pointes. Fatal cardiac arrhythmias have been reported, especially with concurrent use of other QT-prolonging drugs, in patients with electrolyte abnormalities, or with underlying cardiac conditions.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to erythromycin or any macrolide antibiotic","Concurrent use with ergotamine or dihydroergotamine (risk of ergot toxicity)","Pre-existing QT prolongation or concurrent use of QT-prolonging drugs","Severe hepatic impairment"]

Clinical Precautions

Precautions

["Risk of QT prolongation and cardiac arrhythmias","Hepatic dysfunction and cholestatic hepatitis","Clostridium difficile-associated diarrhea (CDAD)","Exacerbation of myasthenia gravis symptoms","Potential for drug interactions with statins, warfarin, and other CYP3A4 substrates"]

Clinical Tips & Counseling

Drug interactions

Loading safety data…

PCE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for PCE (PCE).

How it works

PCE (erythromycin) binds to the 50S subunit of bacterial ribosomes, inhibiting protein synthesis by blocking translocation of peptides.

What the body does with it

Metabolism	Primarily metabolized by the liver via demethylation; CYP3A4 is the major enzyme involved.
Excretion	Primarily renal (about 70-80% as unchanged drug and metabolites via glomerular filtration and tubular secretion); minor biliary/fecal elimination (10-15%).
Half-life	Terminal elimination half-life is approximately 3-5 hours in adults with normal renal function; may be prolonged to 7-10 hours in renal impairment (CrCl <30 mL/min).
Protein binding	Approximately 65-85% bound to serum albumin and alpha-1-acid glycoprotein.
Volume of Distribution	0.5-1.0 L/kg, indicating moderate tissue distribution (e.g., lungs, kidneys, liver); not extensively bound to erythrocytes.
Bioavailability	Oral immediate-release: 85-95% (due to first-pass metabolism, reduced to ~60-80% for extended-release); topical: 10-20% (systemic absorption).
Onset of Action	Oral immediate-release: 1-2 hours; intravenous: within 30 minutes; topical: 2-4 hours.
Duration of Action	Oral immediate-release: 6-8 hours; intravenous: 4-6 hours; topical: 8-12 hours depending on formulation.

Classification & Brands

Dosing & administration

Erythromycin ethylsuccinate (PCE) typical adult dose: 400 mg orally every 6 hours or 800 mg orally every 12 hours. Maximum 4 g/day.

Dosage form	TABLET, COATED PARTICLES
Renal impairment	No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (GFR <10 mL/min), consider dose reduction by 50% or extending interval to every 12 hours due to potential accumulation.
Liver impairment	Child-Pugh Class A: No adjustment. Class B: Reduce dose by 50% or extend interval. Class C: Avoid use; if necessary, reduce dose by 75% with close monitoring.
Pediatric use	Weight-based: 30-50 mg/kg/day in divided doses every 6-12 hours. Maximum 2 g/day.
Geriatric use	Use with caution due to increased risk of QT prolongation and hearing loss. Start at lower end of dosing range (e.g., 400 mg every 12 hours) and monitor renal function, electrolytes, and ECG.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for PCE (PCE).

Breastfeeding	Excreted in breast milk in low levels; M/P ratio not established. Considered compatible with breastfeeding by the American Academy of Pediatrics. Weigh benefits against potential risk of infant gastrointestinal disturbance or rash.
Teratogenic Risk	FDA Pregnancy Category B. First trimester: No evidence of teratogenicity in animal studies; human data limited but no increased risk of major malformations reported. Second and third trimesters: May cause transient neonatal neutropenia if used near term; no known structural anomalies.