Does a antitoxin serum for botchalisum have side effects

Of course.: If you are talking about "botox", it does have side effects and benefits. It all depends on the dosage and the indications. Botox has certain medical indications, injected by experienced doctors for specific treatments to improve specific conditions, as the same we can say for any medication. Different patients respond differently to the same medication.

Yes: There are 2 botulism antitoxins: a trivalent one available from health depts & cdc, & a hepta(7)valent one available from the army. Most common side effects are urticaria (hives), mild hypersensitivity, serum sickness, & anaphylaxis, which can be lessened by desensitization via gradually increasing doses. Newer, safer versions are being developed as preventives. Close medical care req if botulism.