ampicillin

 Indications

Treatment of the following infections: Skin and skin

structure infections, Soft-tissue infections, Otitis media,

Sinusitis, Respiratory infections, Genitourinary infections,

Meningitis, Septicemia. Endocarditis prophylaxis.

Unlabeled Use: Prevention of infection in certain

high-risk patients undergoing cesarean section.

Action

Binds to bacterial cell wall, resulting in cell death.

Therapeutic Effects: Bactericidal action; spectrum

is broader than penicillin. Spectrum: Active against:

Streptococci, nonpenicillinase-producing staphylococci,

Listeria, Pneumococci, Enterococci, Haemophilus

influenzae, Escherichia coli, Enterobacter, Klebsiella,

Proteus mirabilis, Neisseria meningitidis, N.

gonorrhoeae, Shigella, Salmonella.

Pharmacokinetics

Absorption: Moderately absorbed from the duodenum

(30–50%).

Distribution: Diffuses readily into body tissues and

fluids. CSF penetration isqin the presence of inflamed

meninges. Crosses the placenta; enters breast milk in

small amounts.

Metabolism and Excretion: Variably metabolized

by the liver (12–50%). Renal excretion is variable

(25–60% after oral dosing; 50–85% after IM administration).

Half-life: Neonates: 1.7–4 hr; Children and Adults:

1–1.5 hr (qin renal impairment).

TIME/ACTION PROFILE (blood levels)

ROUTE ONSET PEAK DURATION

PO rapid 1.5–2 hr 4–6 hr

IM rapid 1 hr 4–6 hr

IV rapid end of infusion

4–6 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity to penicillins.

Use Cautiously in: Severe renal insufficiency (dose

prequired if CCr 10 mL/min); Infectious mononucleosis,

acute lymphocytic leukemia or cytomegalovirus

infection (qincidence of rash); Patients allergic to

cephalosporins; OB: Has been used during pregnancy;

Lactation: Distributed into breast milk. Can cause rash,

diarrhea, and sensitization in the infant.

Adverse Reactions/Side Effects

CNS: SEIZURES (high doses). GI: CLOSTRIDIUM DIFFICILE-

ASSOCIATED DIARRHEA (CDAD), diarrhea, nausea,

vomiting. Derm: rash, urticaria. Hemat: blood dyscrasias.

Misc: allergic reactions including ANAPHYLAXIS

and SERUM SICKNESS, superinfection.

Interactions

Drug-Drug: Probenecidprenal excretion andq

blood levels of ampicillin—therapy may be combined

for this purpose. Large doses mayqthe risk of bleeding

with warfarin.qrisk of with concurrent allopurinol

therapy. Maypthe effectiveness of oral hormonal

contraceptives.

Route/Dosage

Respiratory and Soft-Tissue Infections

PO (Adults and Children 20 kg): 250–500 mg q

6 hr.

PO (Children 20 kg): 50–100 mg/kg/day in divided

doses q 6–8 hr (not to exceed 2–3 g/day).

IM, IV (Adults and Children 40 kg ): 500 mg to 3

g q 6 hr (not to exceed 14 g/day).

IM, IV (Children 40 kg): 100–200 mg/kg/day in

divided doses q 6–8 hr (not to exceed 12 g/day).

Bacterial Meningitis Caused by H. in- A

fluenzae, Streptococcus pneumoniae,

Group B streptococcus or N. meningitidis

or Septicemia

IM, IV (Adults): 500 mg to 3 g q 6 hr (not to exceed

14 g/day).

IM, IV (Children 1mo): 200–400 mg/kg/day in

divided doses q 6 hr (not to exceed 12 g/day).

IM, IV (Neonates 7 days): 200 mg/kg/day divided q

8 hr.

IM, IV (Neonates 7 days): 300 mg/kg/day divided q

6 hr.

GI/GU Infections other than N. gonorrhoeae

PO (Adults and Children 20 kg): 250–500 mg q

6 hr (larger doses for more serious/chronic infections).

PO (Children 20 kg): 50–100 mg/kg/day in divided

doses q 6 hr.

N. gonorrhoeae

PO (Adults): 3 g with 1 g probenecid.

IM, IV (Adults and Children 40 kg ): 500 mg q 6

hr.

IM, IV (Children 40 kg): 100–200 mg/kg/day in

divided doses q 6–8 hr.

Urethritis Caused by N. gonorrhoeae in

Men

IM, IV (Adults and Children 40 kg ): 500 mg, repeated

8–12 hr later; additional doses may be necessary

for more complicated infections (prostatitis, epididymitis).

Prevention of Bacterial Endocarditis

IM, IV (Adults): 2 g 30 min before procedure (gentamicin

may be added for high-risk patients); additional

1 g may be given 6 hr later for high-risk patients.

IM, IV (Children): 50 mg/kg (not to exceed 2 g) 30

min before procedure (gentamicin may be added for

high-risk patients); additional 25 mg/kg may be given 6

hr later for high-risk patients.

Renal Impairment

(Adults and Children): CCr 10 mL/min—qdosing

interval to q 12 hr.

Availability (generic available)

Capsules: 250 mg, 500 mg. Suspension (wild

cherry flavor): 125 mg/5 mL, 250 mg/5 mL. Powder

for injection: 125 mg/vial, 250 mg/vial, 500 mg/vial, 1

g/vial, 2 g/vial, 10 g/vial.