vancomycin hydrochloride

Action

Binds to bacterial cell wall, inhibiting cell-wall synthesis and causing secondary damage to bacterial membrane

Availability

Capsules: 125 mg, 250 mg

Powder for injection: 500-mg vial, 1-g vial, 5-g vial, 10 g-vial

Indications and dosages

➣ Severe, life-threatening infections caused by susceptible strains of methicillin-resistant staphylococci, Staphylococcus epidermidis, Streptococcus viridans or Streptococcus bovis (alone or combined with an aminoglycoside), or Enterococcus faecalis (combined with an aminoglycoside)

Adults: 500 mg I.V. q 6 hours or 1 g I.V. q 12 hours

Children: 10 mg/kg I.V. q 6 hours

Infants and neonates: Initially, 15 mg/kg I.V., followed by 10 mg/kg I.V. q 8 hours in infants 8 days to 1 month old, or 10 mg/kg I.V. q 12 hours in infants less than 8 days old

➣ Endocarditis prophylaxis in penicillin-allergic patients at moderate risk who are scheduled for dental and other invasive procedures

Adults: 1 g I.V. slowly over 1 to 2 hours, with infusion completed 30 minutes before invasive procedure begins

Children: 20 mg/kg I.V. over 1 to 2 hours, with infusion completed 30 minutes before invasive procedure begins

➣ Enterocolitis caused by Staphylococcus aureus

Adults: 500 mg to 2 g P.O. daily in three or four divided doses for 7 to 10 days

Children: 40 mg/kg P.O. daily in three or four divided doses for 7 to 10 days; total daily dose shouldn't exceed 2 g.

➣ Clostridium difficile-associated diarrhea

Adults: 125 mg P.O. q.i.d. for 10 days

Children: 40 mg/kg P. O. in three or four divided doses for 7 to 10 days; total daily dose shouldn't exceed 2 g.

Dosage adjustment

• Renal impairment

• Elderly patients

Off-label uses

• Peritonitis

• Meningitis

• Intraocular infections

• Febrile neutropenia

Contraindications

• Hypersensitivity to drug

Precautions

Use cautiously in:

• renal impairment, preexisting hearing loss

• concurrent use of anesthetics, immunosuppressants, or nephrotoxic or ototoxic drugs

• elderly patients

• pregnant or breastfeeding patients

• neonates.

Administration

Know that I.V. therapy is ineffective against enterocolitis and pseudomembranous diarrhea.

• For intermittent I.V. infusion, dilute by adding 10 or 20 ml of sterile water for injection to vial containing 500 mg or 1 g of drug, respectively, to yield a concentration of 50 mg/ml. Dilute further by adding at least 100 ml or 200 ml, respectively, of dextrose 5% in water or normal saline solution; infuse over at least 1 hour.

• Don't give by I.M. route.

• Be aware that capsules aren't systemically absorbed; therefore, oral therapy is ineffective in infections other than C. difficile-associated diarrhea and enterocolitis caused by S. aureus.

Keep emergency equipment and epinephrine on hand in case of anaphylaxis.

Adverse reactions

CV: hypotension, cardiac arrest, vascular collapse

EENT: permanent hearing loss, ototoxicity, tinnitus

GI: nausea, vomiting, abdominal pain, pseudomembranous colitis

GU: nephrotoxicity, severe uremia

Hematologic: eosinophilia, leukopenia, neutropenia

Metabolic: hypokalemia

Respiratory: wheezing, dyspnea

Skin: "red man" syndrome (nonallergic histamine reaction with rapid I.V. infusion), rash, urticaria, pruritus, necrosis

Other: chills, fever, thrombophlebitis at injection site, anaphylaxis

Interactions

Drug-drug. Aminoglycosides, amphotericin B, bacitracin, cephalosporins, cisplatin, colistin, nondepolarizing neuromuscular blockers, pentamidine (with parenteral use): increased risk of nephrotoxicity and ototoxicity

Anesthetic agents (with parenteral use): erythema and histamine-like flushing

Drug-diagnostic tests. Albumin, blood urea nitrogen (BUN), creatinine: increased levels

Eosinophils, neutrophils: decreased counts

Potassium: decreased level

Patient monitoring

Monitor closely for signs and symptoms of hypersensitivity reactions, including anaphylaxis.

• Check drug blood level weekly. Therapeutic peak ranges from 30 to 40 g/L; therapeutic trough, 5 to 10 mg/L.

• Assess BUN and creatinine levels every 2 days, or daily in patients with unstable renal function.

• Monitor urine output daily. Weigh patient at least weekly.

• Assess hearing before and during therapy; stay alert for hearing loss. Patient may require baseline and weekly audiograms.

• Check I.V. site often for phlebitis.

• Watch for "red-man" syndrome, which can result from rapid infusion. Signs and symptoms include hypotension, pruritus, and maculopapular rash on face, neck, trunk, and limbs.

• Monitor CBC. Watch for signs and symptoms of blood dyscrasias.

• Closely monitor respiratory status. Stay alert for wheezing and dyspnea.

Monitor vital signs and cardiovascular status, especially for vascular collapse and other signs of impending cardiac arrest.

Patient teaching

• Tell patient he may take with or without food.

• Instruct patient to take oral drug exactly as prescribed for as long as prescribed, even if symptoms improve.

• Explain importance of prophylactic I.V. therapy to patients at risk for endocarditis who are scheduled for invasive procedures.

Advise patient to promptly report rash, hearing loss, breathing problems, and signs and symptoms of "red-man" syndrome, nephrotoxicity, and blood dyscrasias.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.