title: Plasma concentrations of praziquantel after oral administration of single and multiple doses in loggerhead sea turtles (Caretta caretta).
abstract: OBJECTIVE
  To determine the pharmacokinetics of praziquantel following single and multiple oral dosing in loggerhead sea turtles.
  
  
  METHODS
  12 healthy juvenile loggerhead sea turtles.
  
  
  METHODS
  Praziquantel was administered orally as a single dose (25 and 50 mg/kg) to 2 groups of turtles; a multiple-dose study was then performed in which 6 turtles received 3 doses of praziquantel (25 mg/kg, PO) at 3-hour intervals. Blood samples were collected from all turtles before and at intervals after drug administration for assessment of plasma praziquantel concentrations. Pharmacokinetic analyses included maximum observed plasma concentration (Cmax), time to maximum concentration (Tmax), area under the plasma praziquantel concentration-time curve, and mean residence time (MRTt).
  
  
  RESULTS
  Large interanimal variability in plasma praziquantel concentrations was observed for all dosages. One turtle that received 50 mg of praziquantel/kg developed skin lesions within 48 hours of administration. After administration of 25 or 50 mg of praziquantel/kg, mean plasma concentrations were below the limit of quantification after 24 hours. In the multiple-dose group of turtles, mean plasma concentration was 90 ng/mL at the last sampling time-point (48 hours after the first of 3 doses). In the single-dose study, mean Cmax and Tmax with dose were not significantly different between doses. After administration of multiple doses of praziquantel, only MRTt was significantly increased, compared with values after administration of a single 25-mg dose.
  
  
  CONCLUSIONS
  Oral administration of 25 mg of praziquantel/kg 3 times at 3-hour intervals may be appropriate for treatment of loggerhead sea turtles with spirorchidiasis.
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Jacobson
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Harman
authors.forename: Lara K
authors.initials: LK
authors.lastname: Maxwell
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Laille
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood* / Q000493:pharmacokinetics; D019540:Area Under Curve; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D008297:Male; D011223:Praziquantel / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood* / Q000493:pharmacokinetics; D012867:Skin / Q000187:drug effects / Q000473:pathology; D014426:Turtles / Q000097:blood*
chemical_list: D000871:Anthelmintics; D011223:Praziquantel