People die or can be seriously disabled after being bitten by a venomous snake. Different venomous snake species have different effects on the body, but initial treatment is similar - to try and prevent venom entering the general circulation. If it becomes apparent that the venom has reached the bloodstream, the patients start becoming extremely unwell and in these circumstances health staff may give a specific antivenom (made from horse serum). However, antivenom frequently causes adverse effects which can, in themselves, be severe and result in death. There are drugs that can be given with the antivenom to try to reduce these adverse effects, and these include adrenaline, antihistamines, and steroids. The review looked to assess the benefit of giving these drugs along with the antivenom. The review of trials found one trial of 105 people in Sri Lanka looking at adrenaline; and a second trial of 101 people in Brazil looking at an antihistamine (promethazine). Both trials were well designed. Adrenaline showed fewer allergic reactions. There was no benefit seen from giving promethazine, and no trials were found on late allergic responses, nor on corticosteroids.