The lowest observable effect level (LOEL) for myopathy in rats and dogs occurred at exposure levels of 0.8 to 2.3-fold the human therapeutic levels at 6 mg/kg (30-minute intravenous infusion) for patients with normal renal function. As the pharmacokinetics (see section 5.2) is comparable, the safety margins for both methods of administration are very similar.

A study in dogs demonstrated that skeletal myopathy was reduced upon once daily administration as compared to fractionated dosing at same total daily dose, suggesting that myopathic effects in animals were primarily related to time between doses.

Effects on peripheral nerves were observed at higher doses than those associated with skeletal muscle effects in adult rats and dogs, and were primarily related to plasma Cmax. Peripheral nerve changes were characterised by minimal to slight axonal degeneration and were frequently accompanied by functional changes. Reversal of both the microscopic and functional effects was complete within 6 months post-dose. Safety margins for peripheral nerve effects in rats and dogs are 8- and 6-fold, respectively, based on comparison of Cmax values at the No Observed Effect Level (NOEL) with the Cmax achieved on dosing with 30-minute intravenous infusion of 6 mg/kg once daily in patients with normal renal function.

The findings of in vitro and some in vivo studies designed to investigate the mechanism of daptomycin myotoxicity indicate that the plasma membrane of differentiated spontaneously contracting muscle cells is the target of toxicity. The specific cell surface component directly targeted has not been identified. Mitochondrial loss/damage was also observed; however the role and significance of this finding in the overall pathology are unknown. This finding was not associated with an effect on muscle contraction.

In contrast to adult dogs, juvenile dogs appeared to be more sensitive to peripheral nerve lesions as compared to skeletal myopathy. Juvenile dogs developed peripheral and spinal nerve lesions at doses lower than those associated with skeletal muscle toxicity.

Reproductive toxicity testing showed no evidence of effects on fertility, embryofetal, or postnatal development. However, daptomycin can cross the placenta in pregnant rats (see section 5.2). Excretion of daptomycin into milk of lactating animals has not been studied.

Long-term carcinogenicity studies in rodents were not conducted. Daptomycin was not mutagenic or clastogenic in a battery of in vivo and in vitro genotoxicity tests.

6. PHARMACEUTICAL PARTICULARS

6.1 List of excipients

 Sodium hydroxide

6.2 Incompatibilities

 Cubicin is not physically or chemically compatible with glucose-containing solutions. This medicinal product must not be mixed with other medicinal products except those mentioned in section 6.6.

6.3 Shelf life

 3 years

After reconstitution: Chemical and physical in-use stability of the reconstituted solution in the vial has been demonstrated for 12 hours at 25°C and up to 48 hours at 2°C – 8°C. Chemical and physical stability of the diluted solution in infusion bags is established as 12 hours at 25°C or 24 hours at 2°C – 8°C.

For the 30-minute intravenous infusion, the combined storage time (reconstitute