Jornal de Toxicologia Clínica
Acesso livre

Abstrato

Non-Clinical Evidence Supports Anti-Inflammatories as More Effective Medication than Antihistamines against Tarantula Local Effects Envenomation

Bruno Ricardo Alves, Rafael Sutti, Pedro Ismael Da Silva Jr, Rogerio Bertani, Jair Guilherme Santos-Junior, Thomaz Augusto Alves Rocha e Silva, Alessandra Linardi

Background: Tarantulas are the most common invertebrates pets, especially in North America and Europe. The most commercialized genera are from Southern Asia and tropical Americas, represented by Vitalius, found in Southeastern Brazil, and Brachypelma, common in Mexican desert. Bites by these spiders in humans occurs during manipulation and generally result in clinical manifestations such local pain, erythema and oedema, with the possibility of secondary local infection. Hence, the cases are usually treated with prescription free drugs such as antihistamines and anti-inflammatories.

Methods: In this work, we investigated the post treatment with commercial nonsteroidal and steroidal anti- inflammatories and anti-histamines administered by oral and intraperitoneal routes on rat paw oedema induced by venoms of Vitalius dubius and Brachypelma smithi. Hydroplethysmometer standard oedema measurement and Evans blue extravasation were performed. Dose standardization experiments showed that the Vitalius dubius is more potent than Brachypelma smithi, and doses were established at 30 µg/paw and 60 µg/paw respectively.

Results: The oral post-administration of ketoprofen (non-selective cyclooxygenase inhibitor) and prednisolone (steroidal anti-inflammatory) markedly reduced a paw oedema evoked by only Vitalius dubius venom, but loratadine (H1-antihistamine) had negligible effect on rat paw oedema induced by both venoms. Intraperitoneal administration, ketoprofen (20 mg Kg^-1) and loratadine (5 mg Kg^-1) reduced the rat paw oedema induced by Vitalius dubius and Brachypelma smithi while methylprednisolone (10 mg Kg^-1) only inhibited the oedema induced by Vitalius dubius.

Conclusion: These results suggest that the pos-treatment with nonsteroidal and steroidal anti-inflammatory drugs are more potent than antihistamines in attenuating the local effect induced by Vitalius dubius and Brachypelma smithi venoms.