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Ampicillin/Sulbactam

Class: Aminopenicillins
VA Class: AM111
Chemical Name: 4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, [2S-[2α,5α,6β(S*)]]-6-[(Aminophenylacetyl)amino]-3,3-dimethyl-7-oxo-, mixt. with (2S-cis)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid 4,4-dioxide
CAS Number: 94935-63-4


Ampicillin Sodium and Sulbactam Sodium is also contained as an ingredient in the following combinations:
Ampicillin Sodium and Sulbactam Sodium

Medically reviewed by Drugs.com on Feb 2, 2022. Written by ASHP.

Introduction

Antibacterial; β-lactam antibiotic; fixed combination of ampicillin (an aminopenicillin) and sulbactam (a β-lactamase inhibitor).

Uses for Ampicillin/Sulbactam

Bone and Joint Infections

Treatment of bone and joint infections (including osteomyelitis and/or septic arthritis) caused by susceptible β-lactamase-producing bacteria.

Intra-abdominal Infections

Treatment of intra-abdominal infections caused by susceptible β-lactamase-producing Escherichia coli, Klebsiella (including K. pneumoniae), Bacteroides (including B. fragilis), or Enterobacter.

Ampicillin and sulbactam (ampicillin/sulbactam) may be as effective as multiple-drug regimens for treatment of less severe intra-abdominal infections, but an aminoglycoside probably should be used concomitantly for empiric therapy in more serious intra-abdominal infections, including hospital-acquired infections, pending results of in vitro susceptibility tests.

Gynecologic Infections

Treatment of serious gynecologic infections (e.g., endometritis, postpartum endomyometritis, posthysterectomy pelvic cellulitis, vaginal cuff abscess, salpingitis, tubo-ovarian abscess, pelvic peritonitis or abscess, surgical wound sepsis) caused by susceptible β-lactamase-producing E coli or Bacteroides (including B. fragilis).

Treatment of pelvic inflammatory disease (PID). CDC states that a regimen of IV ampicillin/sulbactam with oral or IV doxycycline is an alternative parenteral regimen for treatment of PID; provides good coverage against Chlamydia trachomatis, Neisseria gonorrhoeae, and anaerobes for women with tubo-ovarian abscess.

Respiratory Tract Infections

Treatment of lower respiratory tract infections (including pneumonia, bronchitis, acute exacerbations of chronic bronchitis, bronchiectasis) caused by susceptible Staphylococcus, Streptococcus, Haemophilus influenzae, H. parainfluenzae, Moraxella catarrhalis, E. coli, Klebsiella, or Proteus mirabilis.

ATS and IDSA recommend a regimen of ampicillin/sulbactam with a macrolide (azithromycin or clarithromycin) as one of several options for empiric treatment of nonsevere community-acquired pneumonia (CAP) in hospitalized adults who do not have risk factors for methicillin-resistant S. aureus (MRSA; also known as oxacillin-resistant S. aureus or ORSA) or Pseudomonas aeruginosa.

Has been used for treatment of respiratory tract infections (e.g., pneumonia, tracheobronchitis) or bacteremia caused by Acinetobacter resistant to imipenem and other anti-infectives.

Skin and Skin Structure Infections

Treatment of skin and skin structure infections (e.g., wound infections, cellulitis, ulcers, abscesses, furunculosis) caused by susceptible β-lactamase-producing S. aureus, Enterobacter, E. coli, Klebsiella (including K. pneumoniae), P. mirabilis, Bacteroides (including B. fragilis), or Acinetobacter.

Also has been used for treatment of skin and skin structure infections caused by susceptible S. epidermidis, S. warneri, Enterococcus faecalis, Citrobacter, or Morganella morganii.

Bite Wounds

Empiric treatment of animal or human bites. Active against most likely bite pathogens, including anaerobes, Staphylococcus, Eikenella corrodens, Pasteurella multocida.

Alternative for treatment of infections caused by P. multocida or E. corrodens.

Endocarditis

Treatment of endocarditis.

Although other regimens preferred, AHA states a regimen of ampicillin/sulbactam and an aminoglycoside can be considered as an alternative for treatment of endocarditis involving native valves or prosthetic valves or other prosthetic material caused by β-lactamase-producing Enterococcus. AHA also states ampicillin/sulbactam may be considered an option for treatment of endocarditis cause by fastidious gram-negative bacilli of the HACEK group (i.e., Haemophilus, Aggregatibacter, Cardiobacterium hominis, Eikenella corrodens, Kingella).

Consult current guidelines from AHA for information on management of endocarditis.

Gonorrhea and Associated Infections

Has been used for treatment of uncomplicated gonorrhea caused by susceptible penicillinase-producing strains of N. gonorrhoeae (PPNG) and nonpenicillinase-producing strains. However, CDC has not recommended use of penicillins for treatment of gonococcal infections for over 30 years because of the widespread prevalence of PPNG.

Meningitis

Alternative for treatment of meningitis caused by susceptible H. influenzae, N. meningitidis, or S. pneumoniae. Other drugs generally preferred; treatment failures reported when used for treatment of meningitis caused by K. pneumoniae.

Perioperative Prophylaxis

Perioperative prophylaxis to reduce the incidence of infections in patients undergoing certain contaminated or potentially contaminated surgery (e.g., GI or biliary tract surgery, vaginal or abdominal hysterectomy).

Ampicillin/sulbactam is one of several options recommended for perioperative prophylaxis in patients undergoing biliary tact surgery, colorectal surgery, gynecologic and obstetric procedures (e.g., vaginal, abdominal, or laparoscopic hysterectomy), head and neck surgery (involving incisions through oral or pharyngeal mucosa), non-cardiac thoracic surgery (e.g., lobectomy, pneumonectomy, lung resection, thoracotomy), or urologic procedures involving implanted prosthesis.

Consider local susceptibility patterns of potential pathogens when considering ampicillin/sulbactam for perioperative prophylaxis in procedures that involve exposure to bowel flora (e.g., E. coli) that may be resistant to the drug.

Ampicillin/Sulbactam Dosage and Administration

Administration

Administer by slow IV injection or IV infusion or by IM injection.

Dosage is the same for IM and IV administration; higher serum concentrations usually are attained with IV administration and IV route generally preferred, especially for severe infections.

For solution and drug compatibility information, see Compatibility under Stability.

IV Administration

Reconstitution and Dilution

IV solutions are prepared by reconstituting vials containing 1.5 or 3 g of ampicillin/sulbactam with sterile water for injection to provide solutions containing 375 mg/mL (250 mg of ampicillin and 125 mg of sulbactam per mL). An appropriate volume of the reconstituted solution should then be immediately diluted with a compatible IV solution to yield solutions containing 3–45 mg/mL (2–30 mg of ampicillin and 1–15 mg of sulbactam per mL).

IV solutions should be allowed to stand after dissolution to allow any foaming to dissipate in order to permit visual inspection for complete solubilization.

Rate of Administration

IV injection: Administer slowly over a period of ≥10–15 minutes.

IV infusion: Administer over 15–30 minutes.

IM Administration

IM injections should be made deeply into a large muscle mass.

Reconstitution

IM solutions are prepared by reconstituting vials containing 1.5 or 3 g of ampicillin/sulbactam with 3.2 or 6.4 mL, respectively, of sterile water for injection or 0.5 or 2% lidocaine hydrochloride injection to provide a solution containing 375 mg of the drug per mL (250 mg of ampicillin and 125 mg of sulbactam per mL). Use of lidocaine hydrochloride can minimize local pain associated with IM injection of the drug.

IM solutions should be allowed to stand after dissolution to allow any foaming to dissipate in order to permit visual inspection for complete solubilization.

Use IM solutions within 1 hour after reconstitution.

Dosage

Available as fixed combination ampicillin/sulbactam containing a 2:1 ratio of ampicillin to sulbactam.

Ampicillin component provided as ampicillin sodium and sulbactam component provided as sulbactam sodium; potency of each is expressed in terms of the base.

Dosage of ampicillin/sulbactam usually is expressed in terms of the total (sum) of the dosage of both components of the fixed combination (i.e., dosage of ampicillin plus dosage of sulbactam); pediatric dosage of ampicillin/sulbactam also has been expressed in terms of the ampicillin content.

Pediatric Patients

General Pediatric Dosage
IV

Manufacturer states pediatric patients weighing ≥40 kg may receive the usual adult dosage.

Pediatric patients beyond the neonatal period: AAP recommends 100–200 mg/kg of ampicillin daily (as ampicillin/sulbactam) in 4 divided doses. A dosage of 200–400 mg/kg of ampicillin daily (as ampicillin/sulbactam) in 4 divided doses recommended for meningitis or severe infections caused by resistant S. pneumoniae.

Skin and Skin Structure Infections
IV

Children ≥1 year of age: 300 mg/kg daily (200 mg of ampicillin and 100 mg of sulbactam) in equally divided doses every 6 hours.

Manufacturer states IV treatment in pediatric patients should not exceed 14 days; in clinical studies, most children received an appropriate oral anti-infective after an initial regimen of IV ampicillin/sulbactam.

Pelvic Inflammatory Disease
IV

Adolescents: 3 g (2 g of ampicillin and 1 g of sulbactam) every 6 hours in conjunction with doxycycline (100 mg orally or IV every 12 hours). Parenteral regimen may be discontinued 24–48 hours after clinical improvement; switch to oral regimen of doxycycline (100 mg twice daily) and metronidazole (500 mg twice daily) to complete 14 days of therapy.

Perioperative Prophylaxis†
IV

50 mg/kg of ampicillin (as ampicillin/sulbactam) within 60 minutes prior to initial incision.

May give additional intraoperative doses every 2 hours during prolonged procedures; postoperative doses generally not recommended.

Adults

Intra-abdominal, Gynecologic, or Skin and Skin Structure Infections
IV or IM

1.5 g (1 g of ampicillin and 0.5 g of sulbactam) to 3 g (2 g of ampicillin and 1 g of sulbactam) every 6 hours.

Pelvic Inflammatory Disease
IV

3 g (2 g of ampicillin and 1 g of sulbactam) every 6 hours in conjunction with doxycycline (100 mg orally or IV every 12 hours). Parenteral regimen may be discontinued 24–48 hours after clinical improvement; switch to oral regimen of doxycycline (100 mg twice daily) and metronidazole (500 mg twice daily) to complete 14 days of therapy.

Respiratory Tract Infections†
IV

Empiric treatment of nonsevere CAP in hospitalized adults without risk factors for MRSA or Ps. aeruginosa: ATS and IDSA recommend 1.5 g (1 of ampicillin and 0.5 g of sulbactam) to 3 g (2 g of ampicillin and 1 g of sulbactam) every 6 hours in conjunction with azithromycin (500 mg daily) or clarithromycin (500 mg twice daily).

Endocarditis†
IV

Treatment of endocarditis cause by β-lactamase-producing Enterococcus: AHA recommends 3 g (2 g of ampicillin and 1 g of sulbactam) every 6 hours given in conjunction with an aminoglycoside.

Perioperative Prophylaxis†
IV

3 g (2 g of ampicillin and 1 g of sulbactam) given within 60 minutes prior to initial incision.

May give additional intraoperative doses every 2 hours during prolonged procedures; postoperative doses generally not recommended.

Prescribing Limits

Pediatric Patients

IV

Maximum sulbactam dosage is 4 g (i.e., 8 g of ampicillin and 4 g of sulbactam in fixed combination) daily.

Duration of therapy should be ≤14 days.

Adults

IV or IM

Maximum sulbactam dosage is 4 g (i.e., 8 g of ampicillin and 4 g of sulbactam in fixed combination) daily.

Special Populations

Renal Impairment

Dosage adjustments necessary in patients with renal impairment.

Patients with renal impairment should receive the usually recommended dose but these doses should be given less frequently than usual; dosing intervals are based on the patient’s Clcr. The manufacturer recommends that patients with Clcr ≥30 mL/minute per 1.73 m2 should receive 1.5 g (1 g of ampicillin and 0.5 g of sulbactam) to 3 g (2 g of ampicillin and 1 g of sulbactam) every 6–8 hours and patients with Clcr 15–29 or 5–14 mL/minute per 1.73 m2 should receive these doses every 12 or 24 hours, respectively.

Some clinicians suggest that patients undergoing hemodialysis receive 1.5 g (1 g of ampicillin and 0.5 g of sulbactam) to 3 g (2 g of ampicillin and 1 g of sulbactam) once every 24 hours and that the dose should preferably be given immediately after dialysis.

Geriatric Patients

No dosage adjustments except those related to renal impairment. (See Renal Impairment under Dosage and Administration.)

Cautions for Ampicillin/Sulbactam

Contraindications

  • History of serious hypersensitivity reactions (e.g., anaphylaxis, Stevens-Johnson syndrome) to ampicillin, sulbactam, or other beta-lactam antibacterials (e.g., penicillins, cephalosporins).

  • History of cholestatic jaundice/hepatic dysfunction associated with ampicillin/sulbactam.

Warnings/Precautions

Warnings

Superinfection/Clostridioides difficile-associated Colitis

Possible emergence and overgrowth of nonsusceptible bacteria or fungi (e.g., Pseudomonas, Candida). Discontinue and institute appropriate therapy if superinfection occurs.

Treatment with anti-infectives alters normal colon flora and may permit overgrowth of C. difficile. C. difficile infection (CDI) and C. difficile-associated diarrhea and colitis (CDAD; also known as antibiotic-associated diarrhea and colitis or pseudomembranous colitis) reported with nearly all anti-infectives, including ampicillin/sulbactam, and may range in severity from mild diarrhea to fatal colitis. C. difficile produces toxins A and B which contribute to development of CDAD; hypertoxin-producing strains of C. difficile are associated with increased morbidity and mortality since they may be refractory to anti-infectives and colectomy may be required.

Consider CDAD if diarrhea develops during or after therapy and manage accordingly. Obtain careful medical history since CDAD may occur as late as ≥2 months after anti-infective therapy is discontinued.

If CDAD suspected or confirmed, discontinue anti-infectives not directed against C. difficile as soon as possible. Initiate appropriate anti-infective therapy directed against C. difficile (e.g., fidaxomicin, vancomycin, metronidazole), appropriate supportive therapy (e.g., fluid and electrolyte management, protein supplementation), and surgical evaluation as clinically indicated.

Hepatotoxicity

Has been associated with hepatic dysfunction, including hepatitis and cholestatic jaundice. Although hepatotoxicity usually reversible, deaths reported.

If used in patients with hepatic impairment, monitor hepatic function at regular intervals.

Severe Cutaneous Reactions

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 patient develops a rash, monitor closely and discontinue ampicillin/sulbactam if lesions progress.

Sensitivity Reactions

Hypersensitivity Reactions

Serious and occasionally fatal hypersensitivity reactions, including anaphylaxis, reported with penicillins. These reactions may occur in individuals with a history of penicillin hypersensitivity and/or hypersensitivity reactions to multiple allergens. There have been reports of individuals with a history of penicillin hypersensitivity who have experienced severe reactions when treated with cephalosporins.

Prior to initiation of ampicillin/sulbactam, make careful inquiry regarding previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens.

If an allergic reaction occurs, immediately discontinue ampicillin/sulbactam and institute appropriate therapy as indicated.

General Precautions

Selection and Use of Anti-infectives

To reduce development of drug-resistant bacteria and maintain effectiveness of ampicillin/sulbactam and other antibacterials, use only for treatment or prevention of infections proven or strongly suspected to be caused by susceptible bacteria. Prescribing the drug in the absence of proven or strongly suspected bacterial infection unlikely to provide benefit to the patient and increases risk of development of drug-resistant bacteria.

When selecting or modifying anti-infective therapy, use results of culture and in vitro susceptibility testing. In the absence of such data, consider local epidemiology and susceptibility patterns when selecting anti-infectives for empiric therapy.

Information on test methods and quality control standards for in vitro susceptibility testing of antibacterials and specific interpretive criteria for such testing recognized by FDA is available at [Web]. For most antibacterials, including ampicillin/sulbactam, FDA recognizes the standards published by the Clinical and Laboratory Standards Institute (CLSI).

Mononucleosis

A high percentage of patients with mononucleosis who receive ampicillin develop a skin rash.

Do not use ampicillin in patients with mononucleosis.

Use of Fixed Combination

Consider cautions, precautions, contraindications, and drug interactions associated with both drugs in the fixed combination.

When prescribing, preparing, and dispensing ampicillin/sulbactam, consider that dosage of the fixed combination usually is expressed as the total (sum) of the dosage of each of the 2 components in the fixed combination (i.e., dosage of ampicillin plus dosage of sulbactam).

Sodium Content

Each 1.5 g (1 g of ampicillin and 0.5 g of sulbactam) contains approximately 5 mEq (115 mg) of sodium.

Specific Populations

Pregnancy

There are no adequate and well-controlled studies using ampicillin/sulbactam in pregnant women. Reproduction studies in mice, rats, and rabbits at doses up to 10 times the human dose have not revealed evidence of impaired fertility or harm to the fetus due to ampicillin and sulbactam. Because animal reproduction studies are not always predictive of human response, use during pregnancy only if clearly needed.

Although clinical importance unclear, administration of ampicillin alone to pregnant women has resulted in transient decreases in plasma concentrations of total conjugated estriol, estriol glucuronide, conjugated estrone, and estradiol; this effect also may occur following administration of ampicillin/sulbactam. In studies in guinea pigs, IV ampicillin decreased uterine tone, frequency of contractions, height of contractions, and duration of contractions. However, it is not known whether use of ampicillin/sulbactam in humans during labor or delivery could have any immediate or delayed adverse effects on the fetus, prolong the duration of labor, or increase the likelihood that forceps delivery or other obstetrical intervention or resuscitation of the newborn will be necessary.

Lactation

Both ampicillin and sulbactam are distributed into milk in low concentrations.

Use with caution in nursing women.

Pediatric Use

Safety and efficacy of IV ampicillin/sulbactam established for treatment of skin and skin structure infections in children ≥1 year of age, but not established for treatment of intra-abdominal infections or any other indications in this age group.

Safety and efficacy of IM ampicillin/sulbactam not established for any indication in pediatric patients.

Adverse effects reported in pediatric patients similar to those reported in adults.

Geriatric Use

Serum half-lives of ampicillin and sulbactam slightly longer in geriatric adults than in younger adults; not considered clinically important in geriatric patients with renal function normal for their age.

No dosage adjustments except those related to renal function.

Renal Impairment

Dosage adjustments necessary in renal impairment. (See Renal Impairment under Dosage and Administration.)

Common Adverse Effects

Local reactions (pain at IM or IV injection sites, thrombophlebitis, phlebitis); GI effects (diarrhea, nausea, vomiting), rash.

Interactions for Ampicillin/Sulbactam

Specific Drugs and Laboratory Tests

Drug or Test

Interaction

Comments

Allopurinol

Concomitant use with ampicillin substantially increases incidence of rash reported with ampicillin; data not available regarding concomitant use with ampicillin/sulbactam

Unclear whether potentiation of rash is caused by allopurinol or hyperuricemia present in these patients

Aminoglycosides

In vitro evidence of synergistic antibacterial effects against enterococci; used to therapeutic advantage in treatment of endocarditis and other severe enterococcal infections

Potential in vitro and in vivo inactivation of aminoglycosides

Methotrexate

Penicillins may decrease renal clearance of methotrexate; possible increased methotrexate concentrations and hematologic and GI toxicity

Monitor closely if used concomitantly

Probenecid

Decreased renal tubular secretion of ampicillin and sulbactam; increased and prolonged ampicillin and sulbactam concentrations may occur

Tests for glucose

Possible false-positive reactions in urine glucose tests using Clinitest, Benedict’s solution, or Fehling’s solution

Use glucose tests based on enzymatic glucose oxidase reactions (e.g., Clinistix, Tes-Tape)

Tests for uric acid

Possible falsely increased serum uric acid concentrations when copper-chelate method is used; phosphotungstate and uricase methods appear to be unaffected by ampicillin

Ampicillin/Sulbactam Pharmacokinetics

Absorption

Bioavailability

Peak ampicillin serum concentrations attained with ampicillin/sulbactam are similar to those attained with ampicillin alone.

Peak serum concentrations of ampicillin and sulbactam are attained immediately following completion of a 15-minute IV infusion of ampicillin/sulbactam.

Following IM injection of ampicillin/sulbactam, both drugs are rapidly and almost completely absorbed; peak serum concentrations of ampicillin and sulbactam generally attained within 30–40 and 30–52 minutes, respectively.

Peak serum concentrations and AUCs of ampicillin and sulbactam are slightly higher in geriatric patients than in younger adults, presumably because of reduced renal clearance in the elderly.

Distribution

Extent

Both ampicillin and sulbactam widely are distributed into fluids and tissues, including peritoneal fluid, blister fluid, tissue fluid, sputum, middle ear effusion, intestinal mucosa, bronchial wall, alveolar lining fluid, sternum, pericardium, myocardium, endocardium, prostate, gallbladder, bile, myometrium, salpinges, ovaries, and appendix. Concentrations of the drugs in most of these tissues and fluids are 53–100% of concurrent serum concentrations.

Both ampicillin and sulbactam are distributed into CSF in low concentrations following IV or IM administration. CSF concentrations generally higher in patients with inflamed meninges than in those with uninflamed meninges.

Ampicillin and sulbactam both readily cross the placenta and concentrations in umbilical cord blood may be similar to serum concentrations. Ampicillin and sulbactam both distributed into milk in low concentrations.

Plasma Protein Binding

Ampicillin approximately 15–28% and sulbactam approximately 38% bound to serum proteins.

Elimination

Metabolism

Both ampicillin and sulbactam partially metabolized in the liver. Ampicillin partially metabolized by hydrolysis of the β-lactam ring to penicilloic acid which is microbiologically inactive.

Elimination Route

Both ampicillin and sulbactam eliminated in urine principally by glomerular filtration and tubular secretion. Only small amounts of the drugs eliminated in feces and bile.

Following IM or IV administration of ampicillin/sulbactam in adults with normal renal function, approximately 75–92% of the dose of both ampicillin and sulbactam excreted unchanged in urine within 8 hours.

Ampicillin and sulbactam both removed by hemodialysis.

Half-life

In healthy adults with normal renal function, both ampicillin and sulbactam have a distribution half-life of about 15 minutes and an elimination half-life of about 1 hour.

In infants and children <12 years of age, sulbactam has an elimination half-life of 0.92–1.9 hours. In neonates, half-lives of ampicillin and sulbactam vary inversely with age; as renal tubular function matures, the drugs are cleared more rapidly. In premature neonates ≤6 days of age, half-life of ampicillin averages 9.4 hours and half-life of sulbactam averages 7.9 hours.

Special Populations

Half-lives are slightly longer in geriatric adults than in younger adults (2.2 hours compared with 0.8–1.2 hours in younger adults).

Serum concentrations of both ampicillin and sulbactam are higher and half-lives prolonged in patients with renal impairment. Half-lives of ampicillin and sulbactam average 1.6 and 1.6 hours, respectively, in adults with Clcr 30–60 mL/minute and average 3.4 and 3.7 hours, respectively, in those with Clcr 7–30 mL/minute. In adults with Clcr <7 mL/minute, elimination half-life of ampicillin and sulbactam average 17.4 and 13.4 hours, respectively.

Cystic fibrosis patients may eliminate sulbactam at faster rates than healthy individuals.

Stability

Storage

Parenteral

Powder for Injection or Infusion

20–25°C.

IV solutions containing 45 mg/mL (30 mg of ampicillin and 15 mg of sulbactam per mL) prepared using sterile water for injection or 0.9% sodium chloride injection are stable for 8 hours at 25°C or 48 hours at 4°C; solutions containing 30 mg/mL (20 mg of ampicillin and 10 mg of sulbactam per mL) are stable for 72 hours at 4°C.

IV solutions containing 45 mg/mL (30 mg of ampicillin and 15 mg of sulbactam per mL) in lactated Ringer’s injection or 1/6 M sodium lactate injection are stable for 8 hours at 25°C or for 24 or 8 hours, respectively, when refrigerated at 4°C.

IV solutions containing 30 mg/mL (20 mg of ampicillin and 10 mg of sulbactam per mL) in 5% dextrose injection are stable for 2 hours at 25°C or 4 hours when refrigerated at 4°C; those containing 3 mg/mL (2 mg of ampicillin and 1 mg of sulbactam per mL) are stable for 4 hours at 25°C.

IM solutions containing 375 mg/mL (250 mg of ampicillin and 125 mg of sulbactam per mL) prepared using sterile water for injection or 0.5 or 2% lidocaine hydrochloride injection should be administered within 1 hour after reconstitution.

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Parenteral

Solution Compatibility301

Compatible

Sodium chloride 0.9%

Drug Compatibility
Admixture Compatibility301

Compatible

Aztreonam

Tramadol HCl

Incompatible

Ciprofloxacin

Y-site Compatibility301

Compatible

Amifostine

Anidulafungin

Aztreonam

Bivalirudin

Cangrelor tetrasodium

Ceftolozane sulfate-tazobactam sodium

Dexmedetomidine HCl

Docetaxel

Enalaprilat

Etoposide phosphate

Famotidine

Fenoldopam mesylate

Filgrastim

Fluconazole

Fludarabine phosphate

Gallium nitrate

Gemcitabine HCl

Granisetron HCl

Heparin sodium

Hetastarch in lactated electrolyte injection (Hextend)

Imipenem-cilastatin sodium-relebactam

Insulin, regular

Letermovir

Linezolid

Meperidine HCl

Meropenem-vaborbactam

Morphine sulfate

Paclitaxel

Palonosetron HCl

Pemetrexed sodium

Plazomicin sulfate

Remifentanil HCl

Tacrolimus

Telavancin HCl

Teniposide

Theophylline

Thiotepa

Incompatible

Amiodarone HCl

Ciprofloxacin

Idarubicin HCl

Nicardipine HCl

Ondansetron HCl

Sargramostim

Variable

Cisatracurium besylate

Diltiazem HCl

Vancomycin HCl

Actions and Spectrum

  • Ampicillin/sulbactam is a fixed combination of ampicillin (an aminopenicillin) and sulbactam (a β-lactamase inhibitor).

  • Sulbactam synergistically expands activity of ampicillin against β-lactamase-producing bacteria by irreversibly and competitively inhibiting β-lactamases. Active against bacteria susceptible to ampicillin alone and also active against many β-lactamase-producing bacteria resistant to ampicillin alone.

  • Usually bactericidal.

  • Like other β-lactam antibiotics, antibacterial activity of ampicillin results from inhibition of bacterial cell wall synthesis.

  • Spectrum of activity of ampicillin/sulbactam includes many gram-positive and -negative aerobes and some anaerobes.

  • Gram-positive aerobes: Active in vitro against β-lactamase-producing and non-β-lactamase-producing strains of Staphylococcus, S. epidermidis, and S. saprophyticus. Also active in vitro against Streptococcus pneumoniae, S. pyogenes (group A β-hemolytic streptococci), and Enterococcus faecalis. Methicillin-resistant (oxacillin-resistant) staphylococci are considered resistant to ampicillin/sulbactam.

  • Gram-negative aerobes: Active in vitro against β-lactamase-producing and non-β-lactamase-producing strains of Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella, Proteus mirabilis, and Neisseria gonorrhoeae. Also active in vitro against P. vulgaris, Providencia rettgeri, P. stuartii, and Morganella morganii. Inactive against Pseudomonas aeruginosa.

  • Anaerobes: Active in vitro against Bacteroides (including B. fragilis), Clostridium, Peptococcus, and Peptostreptococcus.

Advice to Patients

  • Advise patients that antibacterials (including ampicillin/sulbactam) should only be used to treat bacterial infections and not used to treat viral infections (e.g., the common cold).

  • Importance of completing full course of treatment, even if feeling better after a few days.

  • Advise patients that skipping doses or not completing the full course of therapy may decrease effectiveness and increase the likelihood that bacteria will develop resistance and will not be treatable with ampicillin/sulbactam or other antibacterials in the future.

  • Importance of discontinuing therapy and informing clinician if an allergic reaction occurs.

  • Advise patients that diarrhea is a common problem caused by anti-infectives and usually ends when the drug is discontinued. Importance of contacting a clinician if watery and bloody stools (with or without stomach cramps and fever) occur during or as late as 2 months or longer after the last dose.

  • Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs.

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.

  • Importance of advising patients of other important precautionary information. (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Ampicillin Sodium and Sulbactam Sodium

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Parenteral

For injection

1 g (of ampicillin) and 0.5 g (of sulbactam) (labeled as a combined total potency of 1.5 g)*

Ampicillin and Sulbactam for Injection

Unasyn

Pfizer

2 g (of ampicillin) and 1 g (of sulbactam) (labeled as a combined total potency of 3 g)*

Ampicillin and Sulbactam for Injection

Unasyn

Pfizer

10 g (of ampicillin) and 5 g (of sulbactam) (labeled as a combined total potency of 15 g) pharmacy bulk package*

Ampicillin and Sulbactam for Injection

Unasyn

Pfizer

AHFS DI Essentials™. © Copyright 2022, Selected Revisions February 2, 2022. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

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