Ampicillin

ampicillin

(am pi sill' in)

ampicillin sodium

Oral:

Ampicin (CAN), Apo-Ampi (CAN), Novo-Ampicillin (CAN), Nu-Ampi (CAN), Penbritin (CAN), Principen

Pregnancy Category B

Drug classes

Antibiotic

Penicillin

Therapeutic actions

Bactericidal action against sensitive organisms; inhibits synthesis of bacterial cell wall, causing cell death.

Indications

·        Treatment of infections caused by susceptible strains of Shigella, Salmonella, E. coli, H. influenzae, P. mirabilis, N. gonorrhoeae, enterococci, gram-positive organisms (penicillin G–sensitive staphylococci, streptococci, pneumococci)

·        Meningitis caused by Neisseria meningitidis

·        Unlabeled use: Prophylaxis in cesarean section in certain high-risk patients

Contraindications and cautions

·        Contraindicated with allergies to penicillins, cephalosporins, or other allergens.

·        Use cautiously with renal disorders.

Available forms

Capsules—250, 500 mg; powder for oral suspension—125 mg/5 mL, 250 mg/5 mL; powder for injection—250, 500 mg, 1, 2 g

Dosages

Maximum recommended dosage: 8–14 mg/day (14 g should be reserved for serious infections, such as meningitis, septicemia); may be given IV, IM, or PO. Use parenteral routes for severe infections, and switch to oral route as soon as possible.

ADULTS

·        Prevention of bacterial endocarditis for GI or GU surgery or instrumentation: 2 g ampicillin IM or IV with gentamicin 1.5 mg/kg IM or IV within 30 minutes of starting procedure. Six hours later give 1 g ampicillin IM or IV or 1 g amoxicillin PO.

·        Prevention of bacterial endocarditis for dental, oral, or upper respiratory procedures: 2 g ampicillin IM or IV within 30 minutes of procedure.

·        STDs in pregnant women and patients allergic to tetracycline: 3.5 g ampicillin PO with 1 g probenecid.

·        Prophylaxis in cesarean section: Single IV or IM dose of 25–100 mg/kg immediately after cord is clamped.

ADULTS AND PEDIATRIC PATIENTS

·        Respiratory and soft-tissue infections:
> 40 kg: 250–500 mg IV or IM q 6 hr.
< 40 kg: 25–50 mg/kg/day IM or IV in equally divided doses at 6–8 hr intervals.
> 20 kg: 250 mg PO q 6 hr.
< 20 kg: 50 mg/kg/day PO in equally divided doses q 6–8 hr.

·        GI and GU infections, including women with N. gonorrhoeae:
> 40 kg: 500 mg IM or IV q 6 hr.
< 40 kg: 50–100 mg/kg/day IM or IV in equally divided doses q 6–8 hr.
> 20 kg: 500 mg PO q 6 hr.
< 20 kg: 100 mg/kg/day PO in equally divided doses q 6–8 hr.

·        Gonococcal infections: 500 mg q 6 hr for penicillin-sensitive organism or for patients > 45 kg, single dose of 3.5 g PO with 1 g probenecid.

·        Bacterial meningitis: 150–200 mg/kg/day by continuous IV drip and then IM injections in equally divided doses q 3–4 hr.

·        Septicemia: 150–200 mg/kg/day IV for at least 3 days, then IM q 3–4 hr.

PEDIATRIC PATIENTS

·        Prevention of bacterial endocarditis for GI or GU surgery or instrumentation: 50 mg/kg ampicillin IM or IV with 1.5 mg/kg gentamicin IM or IV within 30 minutes of procedure. Six hours later give 25 mg/kg ampicillin IM or IV or 25 mg/kg amoxicillin PO.

·        Prevention of bacterial endocarditis for dental, oral, or upper respiratory procedures: 50 mg/kg ampicillin IM or IV within 30 minutes of procedure.

Pharmacokinetics

Route	Onset	Peak	Duration
Oral	30 min	2 hr	6–8 hr
IM	15 min	1 hr	6–8 hr
IV	Immediate	5 min	6–8 hr

Metabolism: T_1/2: 1–2 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Urine, unchanged

IV facts

Preparation: Reconstitute with sterile or bacteriostatic water for injection; piggyback vials may be reconstituted with sodium chloride injection; use reconstituted solution within 1 hr. Do not mix in the same IV solution as other antibiotics. Use within 1 hr after preparation because potency may decrease significantly after that.

Infusion: Direct IV administration; give slowly over 3–5 min. Rapid administration can lead to seizures.

IV drip: Dilute as above before further dilution.

IV piggyback: Administer alone or further dilute with compatible solution.

Compatibility: Ampicillin is compatible with 0.9% sodium chloride, 5% dextrose in water, or 0.45% sodium chloride solution, 10% invert sugar water, M/6 sodium lactate solution, lactated Ringer's solution, sterile water for injection. Diluted solutions are stable for 2–8 hr; check manufacturer's inserts for specifics. Discard solution after allotted time period.

Incompatibility: Do not mix with lidocaine, verapamil, other antibiotics, dextrose solutions.

Y-site incompatibility: Do not give with epinephrine, hydralazine, ondansetron.

Adverse effects

·        CNS: Lethargy, hallucinations, seizures

·        CV: CHF

·        GI: Glossitis, stomatitis, gastritis, sore mouth, furry tongue, black "hairy" tongue, nausea, vomiting, diarrhea, abdominal pain, bloody diarrhea, enterocolitis, pseudomembranous colitis, nonspecific hepatitis

·        GU: Nephritis

·        Hematologic: Anemia, thrombocytopenia, leukopenia, neutropenia, prolonged bleeding time

·        Hypersensitivity: Rash, fever, wheezing, anaphylaxis

·        Local: Pain, phlebitis, thrombosis at injection site (parenteral)

·        Other: Superinfections—oral and rectal moniliasis, vaginitis

Interactions

Drug-drug

·        Increased ampicillin effect with probenecid

·        Increased risk of rash with allopurinol

·        Increased bleeding effect with heparin, oral anticoagulants

·        Decreased effectiveness with tetracyclines, chloramphenicol

·        Decreased efficacy of hormonal contraceptives, atenolol with ampicillin

Drug-food

·        Oral ampicillin may be less effective with food; take on an empty stomach

Drug-lab test

·        False-positive Coombs' test if given IV

·        Decrease in plasma estrogen concentrations in pregnant women

·        False-positive urine glucose tests if Clinitest, Benedict's solution, or Fehling's solution is used; enzymatic glucose oxidase methods (Clinistix, Tes-Tape) should be used to check urine glucose

Nursing considerations

Assessment

·        History: Allergies to penicillins, cephalosporins, or other allergens; renal disorders; lactation

·        Physical: Culture infected area; skin color, lesion; R, adventitious sounds; bowel sounds; CBC, LFTs, renal function tests, serum electrolytes, Hct, urinalysis

Interventions

·        Culture infected area before treatment; reculture area if response is not as expected.

·        Check IV site carefully for signs of thrombosis or drug reaction.

·        Do not give IM injections in the same site; atrophy can occur. Monitor injection sites.

·        Administer oral drug on an empty stomach, 1 hr before or 2 hr after meals with a full glass of water; do not give with fruit juice or soft drinks.

Teaching points

·        Take this drug around-the-clock.

·        Take the full course of therapy; do not stop taking the drug if you feel better.

·        Take the oral drug on an empty stomach, 1 hour before or 2 hours after meals; do not take with fruit juice or soft drinks; the oral solution is stable for 7 days at room temperature or 14 days refrigerated.

·        This antibiotic is specific to your problem and should not be used to self-treat other infections.

·        You may experience these side effects: Nausea, vomiting, GI upset (eat frequent small meals), diarrhea.

·        Report pain or discomfort at sites, unusual bleeding or bruising, mouth sores, rash, hives, fever, itching, severe diarrhea, difficulty breathing.

Adverse effects in Italic are most common; those in Bold are life-threatening.