Effect of dexamethasone associated with serum therapy on treatment of Bothrops jararaca venom-induced paw edema in mice.

Objective And Design: The present study investigates the supposed advantage of using an association of anti-inflammatory drugs and serum therapy to treat mouse paw edema induced by injection of Bothrops jararaca snake venom (BjV).

Material And Methods: Edema was induced by injecting BjV (2 microg) into the footpad of male Swiss mice (20-25 g) and measured by plethysmography. Groups of mice were treated 15, 30 or 45 min after BjV injection with Bothrops antivenom or anti-inflammatory drugs (dexamethasone, indomethacin or zileuton), or with the association of antivenom and each one of these drugs.

Results: Antivenom, dexamethasone and indomethacin were effective in reducing the paw edema when used up to 30 min after BjV injection. Zileuton had the same effect, but only if used up to 15 min after BjV injection. The association of antivenom and dexamethasone showed the greatest inhibitory effect when used up to 45 min after BjV injection. At this time, antivenom or anti-inflammatory drugs administered alone were ineffective.

Conclusion: Results suggest that dexamethasone combination with serum therapy can be beneficial for treatment of inflammatory edema caused by B. jararaca envenomation.