Pharmacodynamics and Arteriovenous Differences of Naloxone in Healthy Participants Exposed to an Opioid

Inclusion Criteria: * American Society of Anesthesiologists (ASA) class I * ECG without pathologic abnormalities * BMI range of 18,5 - 26 kg/m2 * pass the modified allens test to determine collateral circulation of the hand * lab values within reference values at St Olav's Hospital for the relevant haematological and biochemical test for inclusion: * Haemoglobin (male: 13.4-17.0 g/dL, female 11.7 - 15.3 g/dL) * Creatinine (male: 60-105 micromole/L, female 45 - 90 micromole/L) * Aspartate aminotransferases (ASAT) (male: 15-45 U/L, female: 15-35 U/L) * Alanine transaminase (ALAT) (male: 10-70 U/L, female: 10-45 U/L) * Gamma glutamyl transpeptidase (GT) (male: 10-80 U/L, female: 10-45 U/L) * For women in reproductive age: serum HCG (normal under 3 ye/L) * Signed informed consent and expected cooperation of the subjects for the treatment Exclusion Criteria: * Taking any medications including herbal medicines the last week prior to treatment visits * Current or history of drug and/or alcohol abuse (To assess problematic drug or alcohol use we use the CAGE AID screening tool) * History of contact with police or authorities in relation to alcohol or drug offences * History of prolonged use of opioid analgesics * History of prior drug allergy * Pregnant women (HCG over 3 ye/L at inclusion) * Women in reproductive age not using high efficacy contraceptives (Oral contraceptives, Patch (Evra), Implants, Vaginal ring, Hormonal IUD, Copper intra-uterine device (IUD), Sterilization) throughout the study period until their last visit. * Breastfeeding women * Participants with access to remifentanil or other potent opioids in their daily workplace. * Hypersensitivity to naloxone, remifentanil hydrochloride or lidocaine and/or to any of its excipients. * Participants that have participated in previous trials where they have received remifentanil or other opioids. * Participants who have donated 450 ml or more blood within 6 weeks prior to visit 2, or who plan to donate blood within 6 weeks after visit 2 * Any reason why, in the opinion of the investigator, the patient should not participate.