Home
http://www.virbac.fr/ http://www.boehringer-ingelheim.com/ http://www.novartis.com/ http://www.animalhealth.bayerhealthcare.com/
vetcontact
Vetrinär
Tiermedizin
  WELCOME  
vetcontact
Vetrinär
Tiermedizin
  Home  
  Login / Newsletter  
vetcontact
Vetrinär
Tiermedizin
  CONTACTS  
vetcontact
Vetrinär
Tiermedizin
  Classifieds  
  New Products  
  VetCompanies  
  VetSchools  
vetcontact
Vetrinär
Tiermedizin
  PROFESSION  
vetcontact
Vetrinär
Tiermedizin
  Edutainment  
  VetAgenda  
  Presentations  
  Posters  
  ESAVS  
  Specialisation  
vetcontact
Vetrinär
Tiermedizin
  INSIGHT  
vetcontact
Vetrinär
Tiermedizin
  Congress News  
  Picture Galleries  
vetcontact
Vetrinär
Tiermedizin
  PRODUCTS  
vetcontact
Vetrinär
Tiermedizin
  Bayer  
  Boehringer Ing.  
  Novartis  
  Virbac

 
  Simply book for less...  
    

Bovine    Equine    Small Animal Practice    Swine Practice    Articles    Vetjournal    
deutsch english español polski francais
Home / WELCOME / Archiv / Small Animal Practice /     
 
Effects of phenobarbital on thyroid and liver function
Phenobarbital is the drug of choice for control of canine epilepsy. Phenobarbital induces hepatic enzyme activity, can be hepatotoxic, and decreases serum thyroxine (T4) concentrations in some dogs. When are blood checks of thyroid and liver functions reliable? A very interesting study!

The duration of liver enzyme induction and T4 concentration decreases after discontinuation of phenobarbital is unknown.

The purpose of this study was to characterize the changes in serum total T4 (TT4), free T4 (FT4), thyroid-stimulating hormone (TSH), cholesterol and albumin concentrations, and activities in serum of alanine aminotransferase (ALT), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) after discontinuation of long-term phenobarbital administration in normal dogs.

Twelve normal dogs were administered phenobarbital at a dosage of approximately 4.4-6.6 mg/kg PO q12h for 27 weeks.

Blood was collected for analysis before and after 27 weeks of phenobarbital administration and then weekly for 10 weeks after discontinuation of the drug.

The dogs were clinically normal throughout the study period. Serum ALT and ALP activity and TSH and cholesterol concentrations were significantly higher than baseline at week 27. Serum T4 and FT4 were significantly lower. Serum albumin and GGT were not changed from baseline at week 27.

Changes in estimate of thyroid function (TT4, FT4, TSH) persisted for 1-4 weeks after discontinuation of phenobarbital, whereas changes in hepatic enzyme activity (ALT, ALP) and cholesterol concentration resolved in 3-5 weeks.

To avoid false positive results, it is recommended that thyroid testing be performed at least 4 weeks after discontinuation of phenobarbital administration.

Elevated serum activity of hepatic enzymes 6-8 weeks after discontinuation of phenobarbital may indicate hepatic disease.


Source: Gieger TL, Hosgood G, Taboada J, Wolfsheimer KJ, Mueller PB. (2000): Thyroid function and serum hepatic enzyme activity in dogs after phenobarbital administration. In: J Vet Intern Med. 2000 May-Jun;14(3):277-81.



Tell a friend   |   Print version   |   Send this article

SMALL ANIMAL PRACTICE

Bioavailability of suppository acetaminophen in dogsmembers
Does acetaminophen reach a satisfactory biovailability in dogs? An interesting question! This recently published study enrolling healthy and ill animals determines the plasma pharmacokinetics of suppository acetaminophen (APAP). Six healthy client‐owned and 20 clinically ill hospitalized dogs were included in this prospective study.

  • Computed tomographic lymphography for lymph node staging in dogs with malignant tumors members
  • Characterization of ocular melanosis-affected canine melanocytesmembers
  • Nasopharyngeal sialoceles in brachycephalic dogsmembers
  • Enterococcus faecium SF68 on serum cobalamin and folate concentrationsmembers
  • Gastrointestinal eosinophilic sclerosing fibroplasia limited to the mesentery in a catmembers
  • Ion acid-base disturbances and associated mortality in dogsmembers
  • First description of ultrasonic bone curette in canine otic surgerymembers
  • Staining hair samples with a modified Wright-Giemsa stain to diagnose feline dermatophytosismembers
  • Oral extended release hydrocodone as analgesia after TPLOmembers
  • 25OH vitamin D3 serum concentration in dogs with acute polyradiculoneuritismembers
  • Type 1 immune mediated polyarthritis in dogs and temporal relationship to vaccination members
  • Phosphorus and protein supply before diagnosis of chronic kidney disease members


  • [ Home ] [ About ] [ Contact / Request ][ Disclaimer ]

    Copyright © 2001-2016 VetContact GmbH
    All rights reserved