Summary of adverse event reports for veterinary biologic products received by the USDA from 1999 through 2005

Impact of concerning excipients on animal safety: insights for veterinary pharmacotherapy and regulatory considerations

OBJECTIVES

Veterinarians and pharmacists are familiar with the efficacy and safety aspects attributed to active pharmaceutical ingredients included in medicines, but they are rarely concerned with the safety of excipients present in medicines. Although generally recognized as safe, excipients are not chemically inert and may produce adverse events in certain animal populations. This review aims to present excipients of concern to these populations and highlight their relevance for rational veterinary pharmacotherapy.

EVIDENCE ACQUISITION

A comprehensive review of the literature about the existence of adverse reactions in animals caused by pharmaceutical excipients was carried out based on an exploratory study. An overview of the correct conditions of use and safety of these excipients has also been provided, with information about their function, the proportion in which they are included in the different pharmaceutical dosage forms and the usual routes of administration.

RESULTS

We identified 18 excipients considered of concern due to their potential to cause harm to the health of specific animal populations: bentonite, benzalkonium chloride, benzoic acid, benzyl alcohol, ethanol, lactose, mannitol, mineral oil, monosodium glutamate, polyethylene glycol, polysorbate, propylene glycol, sodium benzoate, sodium carboxymethylcellulose, sodium lauryl sulfate, sulfites, polyoxyethylene castor oil derivatives, and xylitol. Among the 135 manuscripts listed, only 24 referred to studies in which the substances were correctly evaluated as excipients.

CONCLUSIONS

Based on the information presented in this review, the authors hope to draw the attention of professionals involved in veterinary pharmacotherapy to the existence of excipients of concern in medicines. This information contributes to rational veterinary pharmacotherapy and supports veterinary pharmacovigilance actions. We hope to shed light on the subject and encourage studies and new manuscripts that address the safety of pharmaceutical excipients to the animal population.

Use of serologic tests to predict resistance to Canine distemper virus-induced disease in vaccinated dogs

The objective of the current study was to determine whether detection of Canine distemper virus (CDV)-specific serum antibodies correlates with resistance to challenge with virulent virus. Virus neutralization (VN) assay results were compared with resistance to viral challenge in 2 unvaccinated Beagle puppies, 9 unvaccinated Beagle dogs (4.4-7.2 years of age), and 9 vaccinated Beagle dogs (3.7-4.7 years of age). Eight of 9 (89%) unvaccinated adult dogs exhibited clinical signs after virus challenge, and 1 (13%) dog died. As compared to adult dogs, the 2 unvaccinated puppies developed more severe clinical signs and either died or were euthanized after challenge. In contrast, no clinical signs were detected after challenge of the 9 adult vaccinated dogs with post-vaccination intervals of up to 4.4 years. In vaccinated dogs, the positive and negative predictive values of VN assay results for resistance to challenge were 100% and 0%, respectively. Results indicate that dogs vaccinated with modified live CDV can be protected from challenge for ≤4.4 years postvaccination and that detection of virus-specific antibodies is predictive of whether dogs are resistant to challenge with virulent virus. Results also indicate that CDV infection in unvaccinated dogs results in age-dependent morbidity and mortality. Knowledge of age-dependent morbidity and mortality, duration of vaccine-induced immunity, and the positive and negative predictive values of detection of virus-specific serum antibodies are useful in development of rational booster vaccination intervals for the prevention of CDV-mediated disease in adult dogs.

Adverse events after vaccine administration in cats: 2,560 cases (2002–2005)

OBJECTIVE

To determine the incidence of vaccine-associated adverse events (VAAEs) diagnosed within 30 days of vaccination in cats and characterize risk factors for their occurrence.

DESIGN

Retrospective cohort study.

ANIMALS

496,189 cats vaccinated at 329 hospitals.

PROCEDURES

Electronic records were searched for VAAEs that occurred after vaccine administration classified by practitioners as nonspecific vaccine reaction, allergic reaction, urticaria, shock, or anaphylaxis. Clinical signs and treatments were reviewed. The association between potential risk factors and a VAAE occurrence was estimated via multivariate logistic regression.

RESULTS

2,560 VAAEs were associated with administration of 1,258,712 doses of vaccine to 496,189 cats (51.6 VAAEs/10,000 cats vaccinated). The risk of a VAAE significantly increased as the number of vaccines administered per office visit increased. Risk was greatest for cats approximately 1 year old; overall risk was greater for neutered versus sexually intact cats. Lethargy with or without fever was the most commonly diagnosed VAAE. No localized reactions recorded in the 30-day period were subsequently diagnosed as neoplasia when followed for 1 to 2 years.

CONCLUSIONS AND CLINICAL RELEVANCE

Although overall VAAE rates were low, young adult neutered cats that received multiple vaccines per office visit were at the greatest risk of a VAAE within 30 days after vaccination. Veterinarians should incorporate these findings into risk communications and limit the number of vaccinations administered concurrently to cats.