[The effect of naloxone and levallorphane following fentanyl on the blood gases, EEG and psychodiagnostic tests (author's transl)].

After administration of fentanyl, 0.15 mg naloxone or levallorphan or placebo were given several times and in increased doses and at same intervals of time to six volunteers. The experiment has been done after the rules of a double blind study. Naloxone has shown its superiority to levallorphan. The study demonstrated a faster and better action of naloxone in the way of a return to initial conditions of respiratory frequency, blood gases, and EEG. The concentration and attention faculties after naloxone have become clearly better in contrary to the results after levallorphan. At the end of an anaesthetic procedure, the greatest care should be given to the patient. First of all effective antagonism of the respiratory depression should be obtained without concomitant sedative and psychomimetic effects. The use of antagonists with agonist properties to reverse respiratory depression due to a morphinomimetic drug is not justified and so naloxone should supplant levallorphan.