Home Drug Guide Ampicillin Sodium; Sulbactam Sodium

Drug Guide

Generic Name

Ampicillin Sodium; Sulbactam Sodium

Brand Names Unasyn

Classification

Therapeutic: Antibacterial, antibiotic

Pharmacological: Penicillin antibiotic combined with beta-lactamase inhibitor

FDA Approved Indications

Infections caused by susceptible bacteria, including respiratory tract infections, urinary tract infections, skin and soft tissue infections, gynecological infections, intra-abdominal infections

Mechanism of Action

Ampicillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to cell lysis. Sulbactam inhibits beta-lactamase enzymes produced by bacteria, protecting ampicillin from degradation, thereby extending its spectrum of activity.

Dosage and Administration

Adult: 1-3 g every 8-12 hours IV or IM, doses may vary based on severity and site of infection

Pediatric: Typically 50-100 mg/kg/day divided every 8-12 hours IV or IM; dosing adjustments needed for renal impairment

Geriatric: Adjust dose based on renal function; no specific age-related contraindications but increased caution due to renal function decline

Renal Impairment: Dose adjustment required; generally, dosage interval increased or reduced depending on renal function

Hepatic Impairment: No specific adjustment required; monitor for hepatic effects if prolonged therapy

Pharmacokinetics

Absorption: IV and IM administration—rapid and complete

Distribution: Widely distributed, including cerebrospinal fluid (CSF) in inflamed meninges

Metabolism: Minimal hepatic metabolism

Excretion: Primarily renal (glomerular filtration and tubular secretion)

Half Life: Approximately 1 hour

Contraindications

History of allergic reactions to penicillins or beta-lactam antibiotics

Precautions

History of allergy to cephalosporins, renal impairment, monitor for superinfections, pregnancy and lactation considerations

Adverse Reactions - Common

Allergic reactions (rash, urticaria) (Uncommon)
Diarrhea (Common)
Nausea, vomiting (Occasional)

Adverse Reactions - Serious

Anaphylaxis (Rare)
Clostridioides difficile-associated diarrhea (Uncommon)
Hematologic reactions (eosinophilia, neutropenia, thrombocytopenia) (Rare)

Drug-Drug Interactions

Aminoglycosides (synergistic effect), Warfarin (altered INR), Probenecid (increases ampicillin levels)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of allergic reactions, assess renal function, monitor for superinfections

Diagnoses:

Risk of allergic reaction
Risk for secondary infections

Implementation: Administer IV/IM doses as prescribed, monitor renal function, ensure adequate hydration to prevent renal precipitation of drug

Evaluation: Evaluate infection resolution, monitor for adverse effects

Patient/Family Teaching

Report any allergic reactions immediately
Complete full course of therapy even if symptomatic improves
Maintain adequate hydration during therapy

Special Considerations

Black Box Warnings: N/A

Genetic Factors: None established

Lab Test Interference: May cause false positive reaction in Coombs test and certain urine glucose tests

Overdose Management

Signs/Symptoms: Gastrointestinal symptoms, seizures (rare), neurotoxicity in renal failure

Treatment: Supportive care, observe, and consider dialysis in severe cases

Storage and Handling

Storage: Store at room temperature (15-30°C), protect from light and moisture

Stability: Stable until the expiration date on the package