Evaluating the heart valve tissue diffusion of amoxicillin in infective endocarditis: a pilot prospective observational non-comparative study.

OBJECTIVES: Treating patients with infective endocarditis (IE) due to streptococci and enterococci currently involves high-dosage antibiotics. Recent literature suggests a 30%-70% diffusion rate could be extrapolated to human heart valve tissue. The objective of this study was to evaluate the diffusion coefficient of amoxicillin in heart valve tissue of patients operated for IE. METHODS: Adult patients were prospectively included that underwent surgery at the European Hospital Georges Pompidou for IE due to streptococci and enterococci and had previous IV amoxicillin treatment. Plasma (taken 48 h preoperatively) and heart valve tissue amoxicillin concentrations were measured with a validated LC-MS/MS method. The MIC values of amoxicillin were measured for all available isolates. RESULTS: Seventeen patients were included. Eleven (64.7%) patients had native valve IE and six (35.3%) had prosthetic valve IE. Fourteen IE cases (82.4%) were due to streptococci, one (5.9%) was due to enterococci and two (11.8%) were Haemophilus spp, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae group infections. Median (IQR) amoxicillin dose administered was 10.5 (8.0-12.0) g/day corresponding to 138.2 (112.5-160.0) mg/kg/day. The median amoxicillin plasma concentrations pre-surgery and intra-tissular weighted concentrations were 31.9 (25.9-51.9) mg/L and 19.0 (7.9-31.4) µg/g, respectively. Median tissue/plasma concentration ratio was 0.47 (0.24-0.67), with a median amoxicillin plasma/MIC ratio of 487 (179-745), and median amoxicillin tissue/MIC ratio of 42 (14-116). CONCLUSIONS: With a significant diffusion coefficient, amoxicillin dosage in heart valve tissues showed a concentration/MIC ratio well above current recommendations for bactericidal activity. Our study suggests that lower doses can be considered for susceptible bacteria.

Lycanthropy as a culture-bound syndrome: a case report and review of the literature.

Lycanthropy is an unusual belief or delusion that one has been transformed into an animal, or behaviors or feelings suggestive of such a belief. We report a case of lycanthropic delusions of becoming a snake in a 47-year-old woman who suffered from a major depressive disorder with psychotic features. We also present a literature review of articles published on the subject in English or French since 1975 identified via a MedLine search using the terms "lycanthropy" or "werewolf." Many case reports have described lycanthropy as a delusional disorder occurring acutely in patients who think they suffer from a demonic possession as a punishment for their acts. In these cases, symptoms are generally rapidly reversible. Lycanthropy seems to be a nonspecific manifestation of many psychiatric diseases, most commonly major depressive disorder with psychotic features. It is largely influenced by the cultural environment of the patient so that the animal species frequently represents the patient's delusional representation of evil. Lycanthropy could be considered a culture-bound syndrome that occurs in association with Axis I, DSM-IV psychiatric pathology.