Brown Recluse Spider Envenomation Medication
- Author: Thomas C Arnold, MD, FAAEM, FACMT; Chief Editor: Rick Kulkarni, MD more...
Medication Summary
Utilize tetanus prophylaxis, analgesics, and antipruritics as needed. Reserve antibiotics for evidence of true infection and do not administer prophylactically.
Although no antivenom is currently approved for use in the United States, several groups in other countries are developing a Loxosceles antivenom.[4] It is only a matter of time before a suitable antivenom may be available in the United States.
Antibiotics
Class Summary
Antibiotics may minimize the local inflammatory component of cutaneous loxoscelism and decrease resulting skin necrosis.
Dapsone (Avlosulfon)
Bactericidal and bacteriostatic against mycobacteria strains. The mechanism of action is similar to that of sulfonamides where competitive antagonists of p-aminobenzoic acids (PABA) prevent the formation of folic acid, causing bacterial growth inhibition.
If used, initiate the treatment with small doses followed by gradual increments. Monitor patients carefully because hypersensitivity, methemoglobinemia, and hemolysis in the presence of G-6-PD deficiency have been reported.
Corticosteroids
Class Summary
These agents have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.
Use of corticosteroids is controversial, but some evidence supports their use in systemic loxoscelism because of their RBC membrane–stabilizing effects.
Methylprednisolone (Solu-Medrol)
Decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing increased capillary permeability.
Prednisone (Deltasone, Orasone, Meticorten)
Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing increased capillary permeability.
Antihistamines
Class Summary
Antihistamines are used to treat minor allergic reactions and anaphylaxis. Diphenhydramine may be used to pretreat patients with prior documentation of minor allergic reactions. These agents may control itching by blocking effects of endogenously released histamine.
Carlton recommends antihistamines and observation alone as treatment for brown recluse spider bites.[5]
Diphenhydramine (Benadryl)
Used for symptomatic relief of allergic symptoms caused by histamine released in response to allergens.
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