Since the late 1970s N-acetylcystein has been used as an antidote after paracetamol intoxication. The treatment is traditionally given as three consecutive infusions for 20 hours and 15 minutes. The total dose given is 300 mg/kg. Half of this amount is given as a bolus during the first 15 minutes of treatment. This regime has proven very efficient in avoiding liver injury. However, side effects, caused by histamine release, are common (10-15%). Symptoms as flush, urticaria and, in rare cases, bronchospasm, angioedema and circulatory shock typically appear during the bolus dose and may lead to interrupted and inadequate treatment. In addition, the regime is complicated leading to a risk of administration errors. During the last years several publications have described the use of a model with two infusions instead of three. The first and the second infusions are merged and given over four hours. The third infusion and the total dose are left unchanged. This modified regime has been shown to reduce side effects and seems not to increase the risk of liver injury. As of November 1, 2019, the Swedish Poisons Information Centre will change its recommendations to the new two-infusion protocol.