The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse.
Abstract: Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three thoroughbred horses and three ponies were vaccinated with a trivalent vaccine containing inactivated strains of A/Equi 1 (Prague), A/Equi 2 (Miami) and A/Equi 2 (Kentucky 81). Antibody titre, serum interferon concentrations, and the pharmacokinetic parameters t1/2 beta, Vc, Vd(ss), Vd(area) and ClB were measured at various intervals after vaccination. Antibody titre increased substantially in only two animals, while plasma interferon was detectable in low concentrations in four subjects. There was no significant change in any parameter describing the pharmacokinetics of theophylline when measured 2, 6, or 12 days after vaccination. It is suggested that the failure of vaccination to substantially increase plasma interferon concentrations, and thereby alter theophylline elimination, was related to the use of an inactivated viral vaccine, the only type available for vaccination of horses against infection with equine influenza. Regular use of such vaccines, as is required by most Racing Authorities, is therefore unlikely to affect drug withdrawal times.
Publication Date: 1986-12-01 PubMed ID: 2433461DOI: 10.1111/j.1365-2885.1986.tb00063.xGoogle Scholar: Lookup
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- Journal Article
Summary
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The research investigated whether horse vaccination against influenza could impact the pharmacokinetics (how the body absorbs, distributes, metabolizes, and excretes a drug) of theophylline, a commonly used drug. The study concluded that no significant changes were observed in any pharmacokinetic parameters, implying that vaccination does not affect theophylline elimination, likely due to the use of inactivated viral vaccines.
Objective of the Research
- The main purpose of this study was to understand if inoculation with equine influenza vaccine had an impact on the pharmacokinetic parameters of theophylline. This was carried out by observing any changes in the distribution and elimination of the drug after the vaccination was administered on horses.
Study Procedure
- The research involved six horses (three thoroughbreds and three ponies). The horses were vaccinated with a trivalent vaccine containing inactivated strains of various influenza viruses.
- The parameters measured were antibody titre, serum interferon concentrations (proteins that play a key role in immune response to viruses), and pharmacokinetics parameters such as half-life, distribution volume, and clearance rate.
- These parameters were observed at various intervals after vaccination. Plasma interferon is another key marker that the study measured as it could indicate a possible impact on theophylline elimination.
Findings
- The study found that only two animals had a substantial increase in antibody titre while plasma interferon was detectable in low concentrations in four subjects.
- No significant change was observed in the pharmacokinetics of theophylline at intervals of two, six, or twelve days after vaccination. This suggests that vaccination does not affect theophylline elimination.
Implications
- The results might be due to the use of an inactivated viral vaccine, which is the standard vaccine used for equine influenza vaccination.
- The findings imply that consistent use of these vaccines as mandated by most Racing Authorities is unlikely to impact the withdrawal times of drugs like theophylline.
Cite This Article
APA
Short CR, Horner MW, Blay PK, Moss MS, Edington N, Clarke CR.
(1986).
The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse.
J Vet Pharmacol Ther, 9(4), 426-432.
https://doi.org/10.1111/j.1365-2885.1986.tb00063.x Publication
Researcher Affiliations
MeSH Terms
- Animals
- Carbon Radioisotopes
- Horses / metabolism
- Influenza A virus / immunology
- Interferons / blood
- Kinetics
- Metabolic Clearance Rate
- Theophylline / blood
- Theophylline / metabolism
- Viral Vaccines / administration & dosage
Citations
This article has been cited 2 times.- Pellegrino P, Perrotta C, Clementi E, Radice S. Vaccine-Drug Interactions: Cytokines, Cytochromes, and Molecular Mechanisms. Drug Saf 2015 Sep;38(9):781-7.
- Errecalde JO, Landoni MF. The pharmacokinetics of a slow-release theophylline preparation in horses after intravenous and oral administration. Vet Res Commun 1992;16(2):131-8.
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