Effect of regulatory withdrawal of drugs and prescription recommendations on the pattern of self-poisonings in Oslo.

A two-year prospective study of 1350 admissions for self-poisoning, covering the Oslo area was undertaken to identify the sources of the toxic agents. After the first year of the study, four barbiturates were withdrawn from the Norwegian market and recommendations were made by the Health Authorities to promote more restrictive attitudes when prescribing psychoactive drugs. The patterns of self-poisonings in the two periods were compared. The withdrawal of four barbiturates resulted in a 55% decrease in the rate of barbiturate poisonings in general (p less than 0.001). No increase could be detected in the rate of self-poisoning with benzodiazepines and other hypnotics, but the incidence of self-poisonings with antidepressants (p less than 0.01) and neuroleptics (p less than 0.01) was found to have increased significantly. The regulations and recommendations resulted in a significant decrease in drugs obtained from doctors randomly consulted (p less than 0.01), and a significant increase in drugs prescribed by psychiatrists (p less than 0.01). Drugs obtained from non-medical sources increased from 28% in the first period to 33.2% in the second. The total number of admissions and toxic agents taken remained unaltered. Thus, regulatory measures can influence the pattern of self-poisoning but do not seem to influence the tendency to abuse drugs or to take an overdose.