Antibiotic with novel mode of action launched for skin infections
A new antibiotic to treat complicated skin and soft tissue infections will be launched by Chiron later this month.
Daptomycin (Cubicin) is a cyclic lipopeptide natural product with a novel
mode of action. It binds to the cell membranes of gram-positive bacteria
causing depolarisation, which leads to rapid inhibition of protein, DNA
and RNA synthesis, resulting in cell death. It is unable to penetrate
the outer membrane of gram-negative organisms and is therefore only active
against gram-positive bacteria.
Cubicin’s summary of product characteristics states that where
gram-negative or certain types of anaerobic bacteria are suspected, daptomycin
should be administered with other appropriate antibiotics.
Chiron says that in two clinical trials daptomycin was shown to be as
effective as vancomycin and semi-synthetic penicillins. Activity against
Staphylococcus aureus, Streptococcus agalactiae, Streptococcus
dysgalactiae equisimilis and Streptococcus pyogenes was demonstrated.
The recommended dose of daptomycin is 4mg/kg, administered by intravenous
infusion once every 24 hours for seven to 14 days or until the infection
is resolved. It is eliminated primarily by the kidneys and dosage adjustments
are necessary in patients with creatinine clearance of <30ml/min.
Increases in plasma creatinine phosphokinase (CPK) levels associated
with muscular pains and weakness and cases of myositis, myoglobinaemia
and rhabdomyolysis have been reported. The SPC recommends that CPK levels
be measured at baseline and at least once weekly throughout treatment.
The adverse reactions most frequently reported during clinical trials
were headache, nausea, vomiting, diarrhoea, muscle pain, fungal infections,
rash, increased CPK and abnormal liver enzymes.
Commenting on the launch, Jonathan Cooke, clinical director of pharmacy
and medicines management at South Manchester University Hospitals NHS
Trust, told The Journal: “With the increased prevalence of antimicrobial
resistance the need for new antibiotics has never been more pressing.
Daptomycin’s mode of action may offer a more bactericidal agent
for the management of difficult infections. Its place in routine therapy
is yet to be fully determined.”
Notice-board p288 |
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