If someone is bitten by a snake and goes into anaphylactic shock (an extreme allergic reaction that can itself be fatal), they will need an antivenom. There are antivenoms for each specific breed of snake. Cho Ray hospital has a list of snakes and antivenoms. if the snake cannot be identified, the venom itself can be tested, so don’t wash the wound.
Poisonous snakes are: Triangular-headed; colorful; “Vampire bite”; lay straight eggs.
Non-poisonous snakes are: Round-headed; less colorful; regular bite; lay elliptical eggs.
For non-poisonous snake bites, wash with water & soap. Control the bleeding. If a poisonous snake killed recently, you may be safe within 24 hours.