The changes in spirometric measurements during 6 months' methadone maintenance treatment in opiate dependent patients

The aim of the study was to evaluate the respiratory system response to individually specified doses of methadone in opiate dependent patients during 6 months' methadone maintenance treatment at the Department of Clinical Toxicology CM UJ. There were 34 persons (14 women aged from 21 to 33 years and 20 men aged 21-46 years) under examination. Examinations were performed three times: I--initial examination--before administration of methadone maintenance treatment; II--control examination after 3 months--methadone maintenance treatment; III--control examination after 6 months--methadone maintenance treatment. Ventilation efficiency was assessed on the basis of the results from a "flow-volume" loop, spirometry and the measurements of the respiratory tract resistance (Rrs) in a computerised system. Rrs was determined by means of the flow-interruption method. The parameters obtained from a "flow-volume" loop and spirometry were stabile within opiate substitution with methadone, whilst the values of respiratory resistance were significantly different. Significant increase in respiratory resistance values between initial and control examination (after 3 months) was noted. The normalisation of respiratory resistance was proved after 6 months treatment. It can indicate the impact of nervous component on spastic reaction of central bronchi.