DAPTOMYCIN

DAPTOMYCIN (dap-to-my'sin) Cubicin Classifications: antibiotic; lipopeptide; Therapeutic: antibiotic; lipopeptide Pregnancy Category: B

Availability

500 mg vial

Action

Daptomycin is cyclic lipopeptide antibiotic. It binds to bacterial membranes of gram-positive bacteria causing rapid depolarization of the membrane potential leading to inhibition of protein, DNA, and RNA synthesis and bacterial cell death.

Therapeutic Effect

Daptomycin is effective against a broad spectrum of gram-positive organisms, including both susceptible and resistant strains of S. aureus.

Uses

Complicated skin and skin structure infections, bacteremia.

Unlabeled Uses

Vancomycin-resistant enterococci.

Contraindications

Pseudomembranous colitis. Safe use in infants or children <18 y is not known.

Cautious Use

Severe renal or hepatic impairment, end-stage renal impairment; peripheral neuropathy; GI disease; history of rhabdomyolysis, myopathy; elderly; pregnancy (category B), lactation.

Route & Dosage

Skin Infections Adult: IV 4 mg/kg q24h x 7–14 d Bacteremia (S. aureus) Adult: IV 6 mg/kg x 2–6 wk Renal Impairment Skin infection: Clcr <30 mL/min: 4 mg/kg q48h; bacteremia: Clcr <30 mL/min: 6 mg/kg q48h Hemodialysis: Dose by Clcr, administer after dialysis

Administration

Intravenous PREPARE: IV Infusion: Reconstitute the 250 mg vial or the 500 mg vial with 5 mL or 10 mL, respectively, of NS to yield 50 mg/mL. Further dilute the 50 mg/mL solution in 50–100 mL of NS.   ADMINISTER: IV Infusion: Infuse over 30 min; if same IV line is used for infusion of other drugs, flush line before/after with NS.   INCOMPATIBILITIES Solution/additive: Dextrose-containing solutions.

• Store unopened vials in 2°–8° C (36°–46° F). Avoid excessive heat. May store reconstituted, single-use vials or IV solution for 12 h at room temperature or 48 h if refrigerated.

Adverse Effects (≥1%)

Body as a Whole: Injection site reactions, fever, fungal infections. CNS: Headache, insomnia, dizziness. CV: Hypotension, hypertension. GI: Constipation, nausea, vomiting, diarrhea, abnormal liver function tests. Hematologic: Anemia. Metabolic: Elevated CPK. Musculoskeletal: Limb pain, arthralgia. Respiratory: Dyspnea. Skin: Rash, pruritus. Urogenital: UTIs, renal failure.

Interactions

Drug: Significant reactions not identified.

Pharmacokinetics

Elimination: Primarily renal. Half-Life: 8 h.

Nursing Implications

Assessment & Drug Effects

• Monitor for and report: muscle pain or weakness, especially with concurrent therapy with HMG-CoA reductase inhibitors (statin drugs); S&S of peripheral neuropathy, superinfection such as candidiasis.
• Lab tests: Perform C&S before treatment is begun; baseline renal function tests; weekly CPK levels; PT/INR during first few days of daptomycin therapy with concurrent warfarin use; daily blood glucose monitoring in diabetics; serum electrolytes if S&S of hypokalemia or hypomagnesemia (see Appendix F) appear.
• Withhold drug and notify physician if S&S of myopathy develop with CPK elevation >1000 U/L (5 x ULN), or if CPK level is ≥10 x ULN.

Patient & Family Education

• Report any of the following to the physician: muscle pain, weakness or unusual tiredness; numbness or tingling; difficulty breathing or shortness of breath; severe diarrhea or vomiting; skin rash or itching.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug