To the Editor: Older people are comprising an increasing number of the world's population. Therefore, this retrospective study was undertaken to determine the incidence of poison exposures in older people and to characterize these poisonings. From a total of 16,500 human adult poison exposures reported to various hospitals in Tehran from March 1992 through August 1993, 384 cases involving patients aged 60 years and older were identified. Each case was examined with respect to sex, age group, reason for exposure, and treatment and agent/drug used. Of these cases reported, 214 persons were hospitalized, 144 were outpatients, and the rest are unknown. Although older people have relatively low poisoning rates, their case fatalities are quite high. We found that 7.6% (29/384) of the deaths that followed poisonings occurred in older people, compared with a 1.3% (165/13,116) fatality rate in the rest of the population (less than 60 years of age). In Table 1, poisoning cases are classified according to the nature of the exposure. The overall male to female ratio was 1.4:1, with males exceeding females in all cases and age groups, except in the suicide group where the number of males was almost equal to the number of females. Table 1 also shows that accidental poisoning was responsible for a significant 32% of all exposures; therefore, the causes of accidental exposures could be of particular interest because they may be amenable to preventive measures. The age distribution of poisoning demonstrated a sharp decline in the number of exposures (suicidal and accidental) with increase in age. Seventy-seven percent of all suicide attempts and 54% of all accidental cases occurred in the 60 to 69 age group. Combining the 60 to 69 and 70 to 79 age groups accounted for 92% of all poisoning cases. It is interesting to note that in all age groups except the 60 to 69 group, accidental cases comprised a significant proportion of the poisonings. In our previous work we demonstrated that 15% (29/194) of the fatalities following poisoning reported by various hospitals in Tehran occurred in persons 60 years of age and older. Activated charcoal and laxative and gastric lavage were used more frequently than ipecac syrup as routine treatment course. We also found that almost 60% of the patients were hospitalized for further treatment. These results confirm that older people are less likely to improve rapidly. Figure 1 further classifies poison exposures according to the type of agent used. Drugs were responsible for almost 50% of all poisoning cases. In the drug group, benzodiazepines were the most frequently used agents (29%, Figure 1), with diazepam accounting for 41 of 64 of these cases. Because benzodiazepines are the most frequently prescribed sedative/hypnotic, the high incidence of poisonings observed with these agents was justified. Our previous work on fatal outcome results from poisoning also indicated that many of the deaths attributable to cardiovascular drugs were accidental in nature and occurred mainly in older people. Cardiac glycosides were responsible for 67% of the cardiovascular drug poisonings. Psychotherapeutic drugs, including antipsychotics and antidepressants, closely followed cardiovascular agents as the cause of poisoning (18%, Figure 1). Tricyclic antidepressants were responsible for almost 60% of the poisonings with these agents. As shown in Figure 1, opiate products (opium, heroin, opiate) were next to drugs in frequency of usage (88 out of 384). The number of poisoning cases attributed to pesticides was also noticeable (8%). More than 60% of the poisonings with pesticides occurred with insecticides, mainly organophosphorus compounds. The results from our previous studies on poisoning cases leading to fatality, placed pesticides second to drugs on the frequency of usage. Chemicals followed pesticides as th next leading cause and were involved in 7% of poisoning cases. Poisoning frequency according to type of drug used. Older people are more likely to use old-fashioned household products such as cleaners and disinfectants in attempts at self poisoning; this is in agreement with the types of products shown in our survey. Depilatory (main ingredients are arsenic and calcium hydroxide) and kerosene oil were also used commonly as poisoning agents by older people. With the improvements in health care standards, the older population is expected to grow. Therefore, future studies are required to further characterize poisonings in older people and to reduce the incidence of poisoning. Educating medical professionals about the trends and special circumstances of poisoning in this population is of utmost importance.