Acetaminophen's Antinociceptive Effect When Associated With N-Acetylcysteneine

Inclusion Criteria: * Male * Between 18 and 45 years old * Without treatment during the 7 days before inclusion specially no use of antalgic and anti-inflammatory * Cooperation and understanding enough to conform to the study obligations -Having given free, informed written consent * Affiliated at system of French social security * Inscription or acceptation of inscription in the national register of volunteers involved in trials. Exclusion Criteria: * Patient with one or many contraindication for the administration of the trial's products, * Patient that have taken N-acetylcysteine as bronchial thinner during the last 3 days, * Patient with medical or surgical history judged by the investigator or his representative as being not compatible with the clinical trial * Patient with disease progression during inclusion, * Patient with excessive consumption of alcohol, tobacco (+ than 10 cigarette/day), coffee, tea or drinks with caffeine (equivalent to more than 4 cup a day) or any addiction to drugs, * Patient with a heat pain mean threshold during training higher or equal to 46.5°C, * Patient who participated in another clinical trial, located in exclusion period or received benefits \> 4500 euros during 12 months before the beginning of trial, * Patient with cooperation and understanding that do not allow him to follow the trial, * Patients with minor or under guardianship, * No affiliation at system of French social security