ampicillin/sulbactam (Rx)

Brand and Other Names:Unasyn
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

powder for solution

  • 1.5g (ampicillin 1g/sulbactam 0.5g)
  • 3g (ampicillin 2g/sulbactam 1g)
  • 15g (ampicillin 10g/sulbactam 5g)

Gynecologic Infections

1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV/IM q6hr; not to exceed 12 g/day

Intra-Abdominal Infections

1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV/IM q6hr; not to exceed 12 g/day

Skin & Skin Structure Infections

1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV/IM q6hr; not to exceed 12 g/day

Orbital Cellulitis

3 g (2 g ampicillin + 1 g sulbactam) IV q6hr

Pelvic Inflammatory Disease

3 g (2 g ampicillin + 1 g sulbactam) IV q6hr

Pneumonia

Aspiration or community acquired: 1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV q6hr for 5 or more days

Hospital acquired: 3 g IV q6hr for 5 or more days

Urinary Tract Infections

Pyelonephritis: 3 g (2 g ampicillin + 1 g sulbactam) IV q6hr for 14 days

Acute Bacterial Rhinosinusitis (Off-label)

Severe infection requiring hospitalization

1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV q6hr for 5-7 days

Endocarditis (Off-label)

Enterococcus infection resistant to penicillin/susceptible to aminoglycosides: 3 g (2 g ampicillin + 1 g sulbactam) IV q6hr for 6 weeks if not aminoglycoside resistant; >6 weeks if aminoglycoside resistant

HACEK infection: 3 g (2 g ampicillin + 1 g sulbactam) IV q6hr for 4 weeks

Dosing Modifications

Renal impairment

  • CrCl 5-14 mL/min/1.73 m²: 1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) IV q24hr
  • CrCl 15-29 mL/min/1.73 m²: 3 g (2 g ampicillin + 1 g sulbactam) IV q12hr
  • CrCl ≥ 30 mL/min/1.73 m²: No dose adjustment necessary

Dosage Forms & Strengths

powder for solution

  • 1.5g (ampicillin 1g/sulbactam 0.5g)
  • 3g (ampicillin 2g/sulbactam 1g)
  • 15g (ampicillin 10g/sulbactam 5g)

Skin Infections

>1 year (<40 kg): 200 mg/kg/day IV divided q6hr; not to exceed 14 days of therapy  

>1 year (>40 kg): 1.5 g (1 g ampicillin + 0.5 g sulbactam) to 3 g (2 g ampicillin + 1 g sulbactam) q6hr; not to exceed 12 g/day

Epiglottitis

Children and adolescents: 100-200 mg ampicillin/kg/day IV divided q6hr  

Mild/Moderate Infection

>1 month-1 year: 100-150 mg ampicillin/kg/day IV/IM divided q6hr  

>1 year: 100-200 mg ampicillin/kg/day IV/IM divided q6hr

Meningitis/Severe Infections

>1 month-1 year: 200-300 mg ampicillin/kg/day IV/IM divided q6hr  

>1 year: 200-400 mg ampicillin/kg/day IV/IM divided q6hr

Peritonsillar and Retropharyngeal Abscess

Children and adolescents: 200 mg ampicillin/kg/day IV divided q6hr  

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Interactions

Interaction Checker

and ampicillin/sulbactam

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    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            >10%

            IM injection site pain (16%)

            1-10%

            Diarrhea (3%)

            IV injection site pain (3%)

            Thrombophlebitis (3%)

            Rash ( < 2%)

            <1%

            Abdominal distention

            Black, "hairy" tongue

            Candidiasis

            Chest pain

            Chills

            Dysuria

            Edema

            Epistaxis

            Erythema

            Fatigue

            Flatulence

            Glossitis

            Headache

            Itching

            Malaise

            Mucosal bleeding

            Nausea

            Pseudomembranous colitis

            Seizure

            Tightness in throat

            Thrombocytopenia

            Urine retention

            Vomiting

            Postmarketing Reports

            Gastrointestinal disorders: Abdominal pain, cholestatic hepatitis, cholestasis, hyperbilirubinemia, jaundice, abnormal hepatic function, melena, gastritis, stomatitis, dyspepsia, and Clostridium difficile associated diarrhea

            Nervous system disorders: Convulsion and dizziness

            Respiratory, Thoracic and mediastinal disorders: Dyspnea

            Skin and subcutaneous tissue disorders: Toxic epidermal necrolysis, Stevens-Johnson syndrome, angioedema, acute generalized exanthematous pustulosis (AGEP), erythema multiforme, exfoliative dermatitis, and urticaria

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            Warnings

            Contraindications

            Hypersensitivity to drug or components

            Patients with previous history of cholestatic jaundice/hepatic dysfunction associated with ampicillin sulbactam

            Cautions

            Use caution in patients with allergy to cephalosporins and carbapenems

            Adjust dose in renal failure

            Prolonged use is associated with fungal or bacterial superinfection

            Hepatic dysfunction, including hepatitis and cholestatic jaundice reported; hepatic toxicity is usually reversible; however, deaths have occurred; monitor hepatic function at regular intervals in patients with hepatic impairment

            A generalized dull red maculopapular rash may occur in 5-10% of children 3-14 days after initiating therapy; carefully evaluate the rash to differentiate a nonallergic ampicillin rash from a hypersensitivity reaction; it normally begins on the trunk and spreads over most of the body; it may be most intense at pressure areas, elbows, and knees

            Hepatotoxicity reported; monitor hepatic function at regular intervals in patients with hepatic impairment

            A high percentage of patients with infectious mononucleosis have developed rash during therapy; therapy is not recommended in these patients

            May cause severe skin reactions, such as toxic epidermal necrolysis (TEN), Stevens- Johnson syndrome (SJS), dermatitis exfoliative, erythema multiforme, and acute generalized exanthematous pustulosis (AGEP); if patients develop skin rash monitor closely and discontinued therapy if lesions progress

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            Pregnancy & Lactation

            Pregnancy category: B

            Lactation: Excreted in breast milk; use caution

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

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            Pharmacology

            Mechanism of Action

            Drug combination of beta-lactamase inhibitor with ampicillin; interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms; alternative to amoxicillin when unable to take medication orally; covers skin, enteric flora, and anaerobes; not ideal for nosocomial pathogens.

            Absorption

            Ampicillin

            • Bioavailability: 30-40%
            • Peak plasma time: 1-2 hr (oral)

            Distribution

            Ampicillin

            • Protein bound: 15-25%
            • Blister and tissue fluids, bile, and CSF with inflamed meninges

            Sulbactam

            • Protein bound: 38%
            • Bile, blister, and tissue fluids

            Metabolism

            Ampicillin and sulbactam

            • Liver

            Elimination

            Ampicillin

            • Half-life: 1-1.8 hr (normal renal function); 7-20 hr (anuria/end-stage renal disease)
            • Excretion: Urine (90% within 24 hr)

            Sulbactam

            • Half-life: 1-1.3 hr
            • Excretion: Urine (75-85%)
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            Administration

            IV Incompatibilities

            Additive: Aminoglycosides, ciprofloxacin

            Y-site: Aminoglycosides, amiodarone, amphotericin B cholesteryl sulfate, ciprofloxacin, cisatracurium(?), diltiazem(?), idarubicin, nicardipine, ondansetron, sargramostim

            IV Compatibilities

            Solution: NS

            Additive: Aztreonam

            Y-site: Amifostine, aztreonam, bivalirudin, cefepime, dexmedetomidine, docetaxel, enalaprilat, etoposide PO4, famotidine, fenoldopam, filgrastim, fluconazole, fludarabine, gatifloxacin, gemcitabine, granisetron, heparin, Hextend, insulin, linezolid, meperidine, morphine, paclitaxel, remifentanil, tacrolimus, teniposide, theophylline, thiotepa, vancomycin

            IV/IM Preparation

            Reconstitute with SWI or 0.5% or 2% lidocaine injection (IM) to obtain a 250 mg ampicillin-125 mg sulbactam/mL solution

            IM: Use within 1 hr after preparation

            IV: Further dilute to 3-45 mg/mL with appropriate diluent

            Use NS for IV piggyback

            IV: Use within 8 hr after preparation

            IV/IM Administration

            Administer around-the-clock to promote less variation in peak and trough serum levels

            Slow IV injection over at least 10-15 min or infusion over 15-30 min

            IM: Deep into large muscle mass

            Storage

            Store intact vials <30°C

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            Formulary

            FormularyPatient Discounts

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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.