Home Drug Guide Erythromycin Ethylsuccinate and Sulfisoxazole Acetyl

Drug Guide

Generic Name

Erythromycin Ethylsuccinate and Sulfisoxazole Acetyl

Brand Names Pediazole, Eryzole, Erythromycin Ethylsuccinate and Sulfisoxazole Acetyl

Classification

Therapeutic: Antibiotic, combination (Macrolide and Sulfonamide)

Pharmacological: Macrolide Antibiotic / Sulfonamide Antibacterial

FDA Approved Indications

Otitis media in children caused by susceptible bacteria

Mechanism of Action

Erythromycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing amino acid transfer. Sulfisoxazole inhibits bacterial folic acid synthesis by competing with para-aminobenzoic acid (PABA). The combination exerts a synergistic antibacterial effect.

Dosage and Administration

Adult: Typically 400 mg erythromycin ethylsuccinate and 1 g sulfisoxazole every 8 hours, adjustment based on infection severity.

Pediatric: Dose varies based on weight/age; typically 40-50 mg/kg/day of erythromycin ethylsuccinate divided into 4 doses, and 50-75 mg/kg/day of sulfisoxazole in divided doses.

Geriatric: Adjust dose if renal/hepatic impairment; monitor for side effects.

Renal Impairment: Use with caution; dosage adjustments needed based on creatinine clearance.

Hepatic Impairment: Use with caution; monitor liver function.

Pharmacokinetics

Absorption: Erythromycin: moderate; Sulfisoxazole: well absorbed from GI tract.

Distribution: Widely distributed, including the inflamed middle ear.

Metabolism: Erythromycin undergoes hepatic metabolism; sulfisoxazole undergoes hepatic conjugation.

Excretion: Erythromycin: biliary/excretion via bile; sulfisoxazole: renal and biliary excretion.

Half Life: Erythromycin: approximately 1.5-2 hours; sulfisoxazole: approximately 9-12 hours.

Contraindications

Hypersensitivity to erythromycin, sulfisoxazole, sulfonamides or macrolides.

Precautions

History of cholestatic jaundice/hepatic dysfunction due to erythromycin; hypersensitivity reactions; use with caution in significant renal or hepatic impairment; monitor for superinfection.

Adverse Reactions - Common

Gastrointestinal upset (nausea, vomiting, diarrhea) (Common)

Adverse Reactions - Serious

Clostridioides difficile-associated diarrhea (Serious but infrequent)
Hepatotoxicity (Rare)
Allergic reactions (rash, anaphylaxis) (Rare)

Drug-Drug Interactions

Potent CYP3A4 inhibitors increase erythromycin levels.
Warfarin: increased bleeding risk.
Other QT-prolonging drugs.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of superinfection, hepatotoxicity, and hypersensitivity.

Diagnoses:

Risk for superinfection
Impaired hepatic function

Implementation: Administer with food to minimize GI upset. Monitor liver function and blood counts.

Evaluation: Assess infection resolution, monitor adverse effects.

Patient/Family Teaching

Complete full course of therapy.
Report any allergic reactions, jaundice, or severe diarrhea.
Take medication with food if GI upset occurs.
Avoid sunlight or tanning beds due to photosensitivity.

Special Considerations

Black Box Warnings: N/A

Genetic Factors: None established.

Lab Test Interference: May cause false-negative pregnancy tests, interfere with liver function tests.

Overdose Management

Signs/Symptoms: Nausea, vomiting, abdominal pain, dizziness.

Treatment: Supportive care, gastric lavage if recent ingestion, activated charcoal if ingestion recent, fluids to prevent dehydration.

Storage and Handling

Storage: Store at room temperature in a dry place.

Stability: Stable for 24 months when stored properly.