Template:Crofab dosing
- Administer antivenom as soon as possible if the indications are met and antivenom is available.[1]
- Administration should slow swelling and decrease pain
Initial Administration
- The dosing of CroFab is the same for adults and children
- Establish initial control of envenomation by giving 4-6 vials
- Control achieved? (Cessation of progression of all components of envenomation, including labs checked 2 hours after infusion started)
- If yes: then perform serial exams and consider maintenance therapy
- If no: repeat infusion of 4-6 vials and then re-evaluate for control
Maintenance therapy
- Maintance therapy may be indicated after initial dosing based on local protocols even if control is achieved.[2]
- Infuse 2-vial doses at 6, 12, and 18hr after initial control achieved
Envenomation control measurement
- Must observe for progression of envenomation during and after antivenom infusion
- Measure limb circumference at several site above and below bite
- Mark advancing border of edema q30min
- Repeat labs q4hr or after each course of antivenom (whichever is more frequent)
Antivenom Side Effects
- Acute reactions occur in <10% pts
- If occurs stop infusion and give antihistamines / epi if needed
- Recurrent thrombocytopenia has been described up to 2 weeks after transfusion with FabAV and is likely a result of isolated renal clearance of FabAV and persistent presence of actual venom in serum.[3]
- Only described in patients with history of thrombocytopenia during hospital course
- Warrants close monitoring of platelets by primary physician or return visit after discharge
- ↑ Dart RC et al. Efficacy of post envenomation administration of antivenin. Toxicon. 1988;26:1218–1221.
- ↑ Crofab treatment agorithmn http://www.crofab.com/documents/CroFab-Treatment_Algorithm.pdf
- ↑ Ruha AM et al. Late hematologic toxicity following treatment of rattlesnake envenomation with crotalidae polyvalent immune Fab antivenom. Toxicon. 2011;57:53–59.