Master Daptomycin (Cubicin) with Picmonic for Medicine

Daptomycin is classified as a lipopeptide antibiotic. These drugs have a structure similar to that of bacteria, with a lipid group attached to a peptide. Because of this, Daptomycin is capable of aggregating in the cell membrane and causing destruction by distortion of the cell membrane.

Once incorporated into the cell membrane of the bacteria, this antibiotic alters their membrane structure, creating porous membranes that can no longer maintain a membrane potential.

After Daptomycin causes a porous membrane to develop, the bacteria can no longer maintain membrane potential. This porous membrane environment allows destabilization of the membrane potential, which interferes with DNA, RNA and protein synthesis, subsequently resulting in cell death.

This antibiotic demonstrates maximum efficacy on thin-walled, gram-positive cocci, particularly those causing skin and soft tissue infections, bacteremia, endocarditis and VRE.

Daptomycin has also demonstrated usefulness in combating methicillin-resistant staphylococcus aureus (MRSA), which is a dangerous organism, given its growing difficulty to satisfactorily eradicate with standard antibiotics.

A common side effect of Daptomycin is myopathy, similar to statin medications. Thus, practitioners should be cautious of myopathy in patients on these medications, particularly if they are given simultaneously.

Daptomycin can lead to muscle tissue damage. In some instances, the muscular involvement may be so severe and rapid that it results in rhabdomyolysis. This is described as the destruction of muscle cells and the subsequent release of their intracellular components into circulation. This can be evaluated by measuring serum levels of creatinine phosphokinase, or CPK. This is a rather high-yield association to recall, so be sure to remember that both statins and Daptomycin are capable of muscular destruction, especially if they are used in conjunction. For this reason, the serum CPK should be measured.

Another side effect to be aware of with Daptomycin use is the development of peripheral neuropathy. Patients can develop changes in distal sensation, such as numbness, tingling, aching, burning, or loss of vibration, temperature and proprioception.

One of the major limitations of this antibiotic is that it is inactivated by surfactant, rendering it useless against pneumonia.

Because Daptomycin is neutralized by surfactant, it should not be used to treat pneumonia.