Ampicillin

MEDICATION SAFETY ISSUES
Sound-alike/look-alike issues:
Ampicillin may be confused with aminophylline

PHARMACOLOGIC CATEGORY
Antibiotic, Penicillin

DOSING: ADULTS
Usual dosage range:
Oral: 250-500 mg every 6 hours
I.M., I.V.: 250-500 mg every 6 hours

Actinomycosis: I.V.: 50 mg/kg/day for 4-6 weeks then oral amoxicillin

Cholangitis (acute): I.V.: 2 g every 4 hours with gentamicin

Diverticulitis: I.M., I.V.: 2 g every 6 hours with metronidazole

Endocarditis:
Infective: I.V.: 12 g/day via continuous infusion or divided every 4 hours
Prophylaxis: Dental, oral, or respiratory tract procedures: I.M., I.V.: 2 g within 30-60 minutes prior to procedure in patients not allergic to penicillin and unable to take oral amoxicillin. Intramuscular injections should be avoided in patients who are receiving anticoagulant therapy. In these circumstances, orally administered regimens should be given whenever possible. Intravenously administered antibiotics should be used for patients who are unable to tolerate or absorb oral medications. Note: American Heart Association (AHA) guidelines now recommend prophylaxis only in patients undergoing invasive procedures and in whom underlying cardiac conditions may predispose to a higher risk of adverse outcomes should infection occur.
Prophylaxis in total joint replacement patient: I.M., I.V.: 2 g 1 hour prior to the procedure
Genitourinary and gastrointestinal tract procedures: I.M., I.V.:
High-risk patients: 2 g within 30 minutes prior to procedure, followed by ampicillin 1 g (or amoxicillin 1g orally) 6 hours later; must be used in combination with gentamicin. Note: As of April 2007, routine prophylaxis for GI/GU procedures is no longer recommended by the AHA.
Moderate-risk patients: 2 g within 30 minutes prior to procedure

Group B strep prophylaxis (intrapartum): I.V.: 2 g initial dose, then 1 g every 4 hours until delivery

Listeria infections: I.V.: 2 g every 4 hours (consider addition of aminoglycoside)

Sepsis/meningitis: I.M., I.V.: 150-250 mg/kg/day divided every 3-4 hours (range: 6-12 g/day)

Urinary tract infections (enterococcus suspected): I.V.: 1-2 g every 6 hours with gentamicin

DOSING: PEDIATRIC

(For additional information see "Ampicillin: Pediatric drug information")
Usual dosage range: Infants and Children:
Oral: 50-100 mg/kg/day in doses divided every 6 hours (maximum: 2-4 g/day)
I.M., I.V.: 100-400 mg/kg/day in divided doses every 6 hours (maximum: 12 g/day)

Endocarditis prophylaxis: Infants and Children: I.M., I.V.:
Dental, oral, or respiratory tract procedures: 50 mg/kg within 30-60 minutes prior to procedure in patients not allergic to penicillin and unable to take oral amoxicillin. Intramuscular injections should be avoided in patients who are receiving anticoagulant therapy. In these circumstances, orally administered regimens should be given whenever possible. Intravenously administered antibiotics should be used for patients who are unable to tolerate or absorb oral medications.
Note: American Heart Association (AHA) guidelines now recommend prophylaxis only in patients undergoing invasive procedures and in whom underlying cardiac conditions may predispose to a higher risk of adverse outcomes should infection occur.
Genitourinary and gastrointestinal tract procedures:
High-risk patients: 50 mg/kg (maximum: 2 g) within 30 minutes prior to procedure, followed by ampicillin 25 mg/kg (or amoxicillin 25 mg/kg orally) 6 hours later; must be used in combination with gentamicin. Note: As of April 2007, routine prophylaxis for GI/GU procedures is no longer recommended by the AHA.
Moderate-risk patients: 50 mg/kg within 30 minutes prior to procedure.

Mild-to-moderate infections: Infants and Children:
Oral: 50-100 mg/kg/day in doses divided every 6 hours (maximum: 2-4 g/day)
I.M., I.V.: 100-150 mg/kg/day in divided doses every 6 hours (maximum: 2-4 g/day)

Severe infections/meningitis: Infants and Children: I.M., I.V.: 200-400 mg/kg/day in divided doses every 6 hours (maximum: 6-12 g/day)

DOSING: ELDERLY — Administer usual adult dose unless renal function is markedly reduced.

DOSING: RENAL IMPAIRMENT
Clcr >50 mL/minute: Administer every 6 hours

Clcr 10-50 mL/minute: Administer every 6-12 hours

Clcr <10 mL/minute: Administer every 12-24 hours

Hemodialysis: Moderately dialyzable (20% to 50%); administer dose after dialysis

Peritoneal dialysis: Moderately dialyzable (20% to 50%)
Administer 250 mg every 12 hours

Continuous arteriovenous or venovenous hemofiltration effects: Dose as for Clcr 10-50 mL/minute; ~50 mg of ampicillin per liter of filtrate is removed

DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Capsule: 250 mg, 500 mg

Injection, powder for reconstitution, as sodium: 125 mg, 250 mg, 500 mg, 1 g, 2 g, 10 g

Powder for oral suspension: 125 mg/5 mL (100 mL, 200 mL); 250 mg/5 mL (100 mL, 200 mL)

DOSAGE FORMS: CONCISE
Capsule: 250 mg, 500 mg

Injection, powder for reconstitution: 125 mg, 250 mg, 500 mg, 1 g, 2 g, 10 g

Powder for oral suspension: 125 mg/5 mL, 250 mg/5 mL

GENERIC EQUIVALENT AVAILABLE — Yes

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

Oral: Administer on an empty stomach (ie, 1 hour prior to, or 2 hours after meals) to increase total absorption.

I.V.: Administer over 3-5 minutes (125-500 mg) or over 10-15 minutes (1-2 g). More rapid infusion may cause seizures. Ampicillin and gentamicin should not be mixed in the same I.V. tubing.

Some penicillins (eg, carbenicillin, ticarcillin, and piperacillin) have been shown to inactivate aminoglycosides in vitro. This has been observed to a greater extent with tobramycin and gentamicin, while amikacin has shown greater stability against inactivation. Concurrent use of these agents may pose a risk of reduced antibacterial efficacy in vivo, particularly in the setting of profound renal impairment. However, definitive clinical evidence is lacking. If combination penicillin/aminoglycoside therapy is desired in a patient with renal dysfunction, separation of doses (if feasible), and routine monitoring of aminoglycoside levels, CBC, and clinical response should be considered.

COMPATIBILITY — Incompatible in D5W, D5NS, D10W, fat emulsion 10%, hetastarch 6%, LR; variable stability (consult detailed reference) in NS.

Y-site administration: Compatible: Acyclovir, amifostine, aztreonam, clarithromycin, cyclophosphamide, docetaxel, doxorubicin liposome, enalaprilat, esmolol, etoposide, famotidine, filgrastim, fludarabine, foscarnet, gatifloxacin, gemcitabine, granisetron, heparin, heparin with hydrocortisone sodium succinate, insulin (regular), labetalol, levofloxacin, linezolid, magnesium sulfate, melphalan, meperidine, morphine, multivitamins, ofloxacin, perphenazine, phytonadione, potassium chloride, propofol, remifentanil, tacrolimus, teniposide, theophylline, thiotepa, tolazoline, vitamin B complex with C. Incompatible: Amphotericin B cholesteryl sulfate complex, epinephrine, fluconazole, hydralazine, midazolam, ondansetron, sargramostim, verapamil, vinorelbine. Variable (consult detailed reference): Calcium gluconate, cisatracurium, diltiazem, hetastarch, hydromorphone, vancomycin.

Compatibility in syringe: Compatible: Chloramphenicol, colistimethate, diatrizoate meglumine 52%, diatrizoate sodium 8%, diatrizoate sodium 60%, heparin, iohexol, iopamidol, iothalamate meglumine 60%, ioxaglate meglumine 39.3%, ioxaglate 19.6%, procaine. Incompatible: Erythromycin lactobionate, gentamicin, hydromorphone, kanamycin, lincomycin, metoclopramide. Variable (consult detailed reference): Lidocaine, polymyxin B sulfate, streptomycin.

Compatibility when admixed: Compatible: Clindamycin, erythromycin lactobionate, floxacillin, furosemide. Incompatible: Amikacin, chlorpromazine, dopamine, gentamicin, hydralazine, prochlorperazine. Variable (consult detailed reference): Aztreonam, cefepime, cimetidine, heparin, hydrocortisone sodium succinate, metronidazole, metronidazole with sodium bicarbonate, ranitidine, sodium bicarbonate, verapamil.

USE — Treatment of susceptible bacterial infections (nonbeta-lactamase-producing organisms); treatment or prophylaxis of infective endocarditis; susceptible bacterial infections caused by streptococci, pneumococci, nonpenicillinase-producing staphylococci, Listeria, meningococci; some strains of H. influenzae, Salmonella, Shigella, E. coli, Enterobacter, and Klebsiella

ADVERSE REACTIONS SIGNIFICANT — Frequency not defined.

Central nervous system: Fever, penicillin encephalopathy, seizure

Dermatologic: Erythema multiforme, exfoliative dermatitis, rash, urticaria
Note: Appearance of a rash should be carefully evaluated to differentiate (if possible) nonallergic ampicillin rash from hypersensitivity reaction. Incidence is higher in patients with viral infection, Salmonella infection, lymphocytic leukemia, or patients that have hyperuricemia.

Gastrointestinal: Black hairy tongue, diarrhea, enterocolitis, glossitis, nausea, pseudomembranous colitis, sore mouth or tongue, stomatitis, vomiting, oral candidiasis

Hematologic: Agranulocytosis, anemia, hemolytic anemia, eosinophilia, leukopenia, thrombocytopenia purpura

Hepatic: AST increased

Renal: Interstitial nephritis (rare)

Respiratory: Laryngeal stridor

Miscellaneous: Anaphylaxis, serum sickness-like reaction

CONTRAINDICATIONS — Hypersensitivity to ampicillin, any component of the formulation, or other penicillins

WARNINGS / PRECAUTIONS
Concerns related to adverse effects: Anaphylactoid/hypersensitivity reactions: Serious and occasionally severe or fatal hypersensitivity (anaphylactoid) reactions have been reported in patients on penicillin therapy, especially with a history of beta-lactam hypersensitivity, history of sensitivity to multiple allergens, or previous IgE-mediated reactions (eg, anaphylaxis, angioedema, urticaria). Use with caution in asthmatic patients. Rash: Appearance of a rash should be carefully evaluated to differentiate a nonallergic ampicillin rash from a hypersensitivity reaction; rash occurs in 5% to 10% of children and is a generalized dull red, maculopapular rash, generally appearing 3-14 days after the start of therapy. It normally begins on the trunk and spreads over most of the body. It may be most intense at pressure areas, elbows, and knees. Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.

Disease-related concerns: Infectious mononucleosis: A high percentage of patients with infectious mononucleosis have developed rash during therapy; ampicillin-class antibiotics not recommended in these patients. Renal impairment: Use with caution in patients with renal impairment; dosage adjustment recommended.

DRUG INTERACTIONS
Allopurinol: May enhance the potential for allergic or hypersensitivity reactions to Ampicillin. Risk C: Monitor therapy

Atenolol: Ampicillin may decrease the bioavailability of Atenolol. Risk C: Monitor therapy

Fusidic Acid: May diminish the therapeutic effect of Penicillins. Risk D: Consider therapy modification

Methotrexate: Penicillins may decrease the excretion of Methotrexate. Risk C: Monitor therapy

Mycophenolate: Penicillins may decrease serum concentrations of the active metabolite(s) of Mycophenolate. This effect appears to be the result of impaired enterohepatic recirculation. Risk C: Monitor therapy

Tetracycline Derivatives: May diminish the therapeutic effect of Penicillins. Risk D: Consider therapy modification

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Risk D: Consider therapy modification

Uricosuric Agents: May decrease the excretion of Penicillins. Risk C: Monitor therapy

ETHANOL / NUTRITION / HERB INTERACTIONS — Food: Food decreases ampicillin absorption rate; may decrease ampicillin serum concentration.

PREGNANCY RISK FACTOR — B (show table)

PREGNANCY IMPLICATIONS — Adverse events have not been observed in animal studies; therefore, ampicillin is classified as pregnancy category B. Ampicillin crosses the human placenta, providing detectable concentrations in the cord serum and amniotic fluid. Most studies have not identified a teratogenic potential for ampicillin use during pregnancy. Two possible associations (congenital heart disease and cleft palate) have been noted; each of these was observed in a single study, was not substantiated by other studies, and may have been chance associations. Ampicillin is recommended for use in pregnant women for the management of premature rupture of membranes. Ampicillin is considered an acceptable alternative to penicillin for the prevention of early-onset Group B Streptococcal (GBS) disease in newborns.

The volume of distribution of ampicillin is increased during pregnancy and the half-life is decreased. As a result, serum concentrations in pregnant patients are approximately 50% of those in nonpregnant patients receiving the same dose. Higher doses may be needed during pregnancy. Although oral absorption is not altered during pregnancy, oral ampicillin is poorly-absorbed during labor.

LACTATION — Enters breast milk/use caution

BREAST-FEEDING CONSIDERATIONS — Ampicillin is excreted in breast milk. The manufacturer recommends that caution be exercised when administering ampicillin to nursing women. Due to the low concentrations in human milk, minimal toxicity would be expected in the nursing infant. Nondose-related effects could include modification of bowel flora and allergic sensitization.

DIETARY CONSIDERATIONS — Take on an empty stomach 1 hour before or 2 hours after meals.

Sodium content of 5 mL suspension (250 mg/5 mL): 10 mg (0.4 mEq)

Sodium content of 1 g: 66.7 mg (3 mEq)

PRICING — (data from drugstore.com)
Capsules (Ampicillin)
250 mg (30): $12.99
250 mg (90): $31.95
500 mg (100): $49.99

MONITORING PARAMETERS — With prolonged therapy, monitor renal, hepatic, and hematologic function periodically; observe signs and symptoms of anaphylaxis during first dose

CANADIAN BRAND NAMES — Apo-Ampi®; Novo-Ampicillin; Nu-Ampi

INTERNATIONAL BRAND NAMES — Alphacin (AU, NZ); Alphapen (MX); Ambiopi (ID); Amcopen (PK); Amfipen (AE, BH, CY, EG, GB, IE, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SY, YE); Amipenix (JP); Ampecu (EC); Ampen (VE); Ampenolet (GR); Ampiblan (CO); Ampicher (EC); Ampicil (BR); Ampicilina (EC); Ampicillin (PL); Ampicin (PH); Ampiclox (SG); Ampico (PH); Ampicyn (AU); Ampidar (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SY, YE); Ampifen (NL); Ampiflex (PE); Ampiger (BR); Ampilag (BF, BJ, CI, ET, GH, GM, GN, KE, LR, MA, ML, MR, MU, MW, NE, NG, SC, SD, SL, SN, TN, TZ, UG, ZA, ZM, ZW); Ampilin (IN); Ampillin (MY); Ampimedin (PY); Ampipen (IN, ZA); Ampitenk (AR); Ampitrex (PH); Ampivral (CO); Ampliblan (CO); Ampolin (TW); Amsapen (MX); Ancillin (TW); Binotal (AT, BR, CO, EC, MX, UY); Biocil (MY); Bridopen (PH); Brupen (MX); Camicil (BF, BJ, CI, ET, GH, GM, GN, KE, LR, MA, ML, MR, MU, MW, NE, NG, SC, SD, SL, SN, TN, TZ, UG, ZA, ZM, ZW); Cilisod (TW); Citicil (IT); Clovillin (PH); Dhacillin (HK, MY); Dibacilina (MX); Doktacillin (SE); Duacillin (MY); Eurocin (PH); Excillin (PH); Extrapen (AE, BF, BH, BJ, CI, CY, EG, ET, GH, GM, GN, IL, IQ, IR, JO, KE, KW, LB, LR, LY, MA, ML, MR, MU, MW, NE, NG, OM, QA, SA, SC, SD, SL, SN, SY, TN, TZ, UG, YE, ZA, ZM, ZW); Flamicina (MX); Gramcil (PH); Ibimycin (AU); Intramed (ZA); Iwacillin (JP); Julphapen (PE); Magnapen (PE); Marovilina (MX); Maxipen (CO); Microcilin (PH); Omnipen (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, MX, OM, PE, QA, SA, SY, YE); Pamecil (BF, BJ, CI, ET, GH, GM, GN, HK, KE, LR, MA, ML, MR, MU, MW, MY, NE, NG, SC, SD, SG, SL, SN, TN, TZ, UG, ZA, ZM, ZW); Panacta (PH); Pelitin (TW); Penbritin (AE, BF, BH, BJ, CI, CY, EG, ET, GH, GM, GN, HK, IE, IL, IQ, IR, JO, KE, KW, LB, LR, LY, MA, ML, MR, MU, MW, MX, MY, NE, NG, OM, QA, SA, SC, SD, SL, SN, SY, TN, TZ, UG, YE, ZA, ZM, ZW); Penibrin (IL); Pentrexyl (BE, BF, BJ, CI, DK, ET, GB, GH, GM, GN, GR, IT, KE, LR, MA, ML, MR, MU, MW, MX, NE, NG, NL, NO, PE, SC, SD, SL, SN, TH, TN, TZ, UG, ZA, ZM, ZW); Petercillin (ZA); Picaplin (TW); Polypen (PH); Primapen (ID); Promecilina (MX); Radiocillina (AE, BF, BH, BJ, CI, CY, EG, ET, GH, GM, GN, IL, IQ, IR, JO, KE, KW, LB, LR, LY, MA, ML, MR, MU, MW, NE, NG, OM, QA, SA, SC, SD, SL, SN, SY, TN, TZ, UG, YE, ZA, ZM, ZW); Rimacillin (AE, BB, BF, BH, BJ, BM, BS, BZ, CI, CY, EG, ET, GH, GM, GN, GY, IL, IQ, IR, JM, JO, KE, KW, LB, LR, LY, MA, ML, MR, MU, MW, NE, NG, NL, OM, QA, SA, SC, SD, SL, SN, SR, SY, TN, TT, TZ, UG, YE, ZA, ZM, ZW); Roscillin (IN); Sanpicillin (ID); Semicillin (HN); Shacillin (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SY, YE); Sintelin (PE); Standacillin (AE, BG, BH, CY, EE, EG, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SY, YE); Standcillin (MY); Synthocilin (IN); Totapen (FR); Tricil (BF, BJ, CI, ET, GH, GM, GN, KE, LR, MA, ML, MR, MU, MW, NE, NG, SC, SD, SL, SN, TN, TZ, UG, ZA, ZM, ZW); Trifalicina (AR); Trilaxin (PH); Vacillin (TH); Viccillin (ID); Vidopen (GB, IE); Virucil (CO); Winpicillin (TW)

MECHANISM OF ACTION — Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs) which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.

PHARMACODYNAMICS / KINETICS
Absorption: Oral: 50%

Distribution: Bile, blister, and tissue fluids; penetration into CSF occurs with inflamed meninges only, good only with inflammation (exceeds usual MICs)
Normal meninges: Nil; Inflamed meninges: 5% to 10%

Protein binding: 15% to 25%

Half-life elimination:
Children and Adults: 1-1.8 hours
Anuria/end-stage renal disease: 7-20 hours

Time to peak: Oral: Within 1-2 hours

Excretion: Urine (~90% as unchanged drug) within 24 hours

PATIENT INFORMATION — Report diarrhea promptly; take entire course of medication; females should report onset of symptoms of candidal vaginitis