TiHo Bibliothek elib - Tierärztliche Hochschule Hannover

Falldarstellung
However, at the initial presentation to the VESC, the animal received one injection of
cefovecin sodium (8 mg/kg, SQ, once) but, clinically worsened over the next four
days and needed subsequent therapies.
Lipid solubility is also important for drug delivery to the CNS. Lipophilic drugs, such
as enrofloxacin, are better able to penetrate the CNS (Maddison et al 2008) and can
achieve higher concentrations. However, fluoroquinolones also have to be used with
caution due to their central nervous system toxicity with higher doses (Brown 1996).
Metronidazole is also highly lipophilic and achieves excellent penetration of tissues,
including the CNS and abscesses (Maddison et al, 2008).
Fluoroquinolones are of great value for the treatment of CNS infections caused by
gram-negative aerobic bacilli but, depending on the agent chosen, they have limited
value for treatment of gram positive bacteria. Because of their relatively high CNS
toxicity and ability to penetrate the CNS in the absence of meningeal inflammation, a
strong increase of their systemic dose as with β-lactam antibiotics is not
recommended (Nau et al. 2010). The patient presented in this case was treated with
enrofloxacin (10mg/kg, IV, q 12 hrs) and continued to receive oral enrofloxacin
(8mg/kg, PO, q 24 hrs) for four months. The dog did not develop seizures.
Another consideration in CSF bioavailability of antibiotics is the plasma protein
binding. In the presence of an intact barrier, only the plasma fraction unbound can
freely penetrate. The majority of fluoroquinolone molecules are unbound to plasma
proteins. Conversely, macrolides and lincosamides such as clindamycin are highly
bound to plasma proteins and therefore relative CNS concentrations are low (20% of
plasma concentration) (Maddison et al 2008). However, these medications can still
be clinically effective (Maddison et al 2008). Although the penetration of clindamycin
into the CNS is considered poor, it can reach therapeutic CSF concentrations after a
single injection of high-dose clindamycin even without meningeal inflammation (Gatti
et al. 1998). Clindamycin is active against gram- positive cocci including penicillin
resistant staphylococci, anaerobes and mycoplasma (Ramsey 2008). In this patient
clindamycin phosphate was administered at (19.5mg/kg, IV, q 12 hrs) during the
hospitalization period and continued at home (15mg/kg, PO, q 12 hrs) for four
months.
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