antivenom, after proposing that IM antivenom took longer to reach the blood serum. Isbister subsequently found the difference between IV and IM routes of administration was, at best, small and did not justify routinely choosing one route over the other. These concerns led two handbooks to recommend IV in preference to IM administration in Australian practice. Despite a long history of usage and anecdotal evidence of effectiveness, there is a lack of data from controlled studies confirming the antivenom's benefits. In 2014 Isbister and others conducted a randomized controlled trial of intravenous antivenom versus placebo for Redback envenomation, finding the addition of antivenom did not significantly improve pain or systemic effects, while antivenom resulted in acute hypersensitivity reactions in 3.6 per cent of those receiving it. The question of abandoning the antivenom on the basis of this and previous studies came up in the Annals of Emergency Medicine in 2015 where White and Weinstein argued that if the recommendations in the 2014 Isbister et al. paper were followed it would lead to abandonment of antivenom as a treatment option, an outcome White and Weinstein considered undesirable. Authors of the 2014 Isbister et al. paper responded in the same issue by suggesting patients for whom antivenom is considered should be fully informed "there is considerable weight of evidence to suggest it is no better than placebo", and in light of a risk of anaphylaxis and serum sickness, "routine use of the antivenom is therefore not recommended". Before the introduction of antivenom, benzodiazepines and intravenous calcium gluconate were used to relieve symptoms of pain and distress, although calcium is not recommended as its benefit has not been shown in clinical trials. Studies support the safety of antivenom, with around a 5% chance of an acute reaction, 1–2% of anaphylaxis and 10% chance of a delayed reaction due to serum sickness. Nevertheless, it is recommended that an injection of adrenaline be ready and available in case it is needed to treat a severe anaphylactic reaction, and also that the antivenom from the vial be administered diluted in a 100 ml bag of intravenous solution for infusion over 30 minutes. While it is rare that patients report symptoms of envenomation lasting weeks or months following a bite, there are case reports from the 1990s in which antivenom was reported to be effective in the relief of chronic symptoms when administered weeks or months after