Healthy Aging & Clinical Care in the Elderly

Acute bacterial skin and skin structure infections (ABSSSI) are common in the elderly and are often complicated due to several factors, including higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and presence of comorbidities compared to younger patients. Daptomycin, a cyclic lipopeptide, exhibits excellent in vitro bactericidal activity against MRSA and other Gram-positive bacteria associated with complicated skin and skin structure infections (cSSSI). Daptomycin achieves adequate drug penetration into inflamed soft tissues, and is primarily cleared by the kidneys. Typical daptomycin dosing for cSSSI is 4 mg/kg, using actual body weight. While some data are available for the safety and efficacy of doses up 12 mg/kg, higher doses should be reserved for serious and invasive infections.

In comparative studies daptomycin was non-inferior to comparator drugs (including vancomycin or penicillinase-resistant penicillins) for treatment of cSSSI. The overall response rate for daptomycin was greater than 80%. Post-marketing analyses of daptomycin therapy for cSSSI have shown similar clinical success of greater than 80%, even in older patients.

Daptomycin was generally well-tolerated. The most common side effects were constipation, nausea, and headaches. The incidences of muscle toxicity were similar between daptomycin and comparator antibiotics (less than 5%). However, the risk of skeletal muscle toxicity may increase when higher doses of daptomycin are used. As such, creatinine phosphokinase should be monitored regularly while a patient is on daptomycin therapy. If possible, daptomycin susceptibility should be performed at baseline and when treatment failure is suspected.

Based on the current available data, daptomycin appears to be a viable alternative to standard treatment options for cSSSI.