Original Contribution

A Study of Poisonings in Adults at the Poison Control Center in Loghman Hakeem Hospital, Tehran, Iran, from April 25, 2000 to April 25, 2001

Hassan Vatandoost, M.D., M.P.H. [1]
Seyed Mostafa Mirakbari, M.D. [1]
Dean Filandrinos, Pharm.D., M.S. [2,3]

Int J Med Toxicol 2001; 4(5): 39


Author Affiliation

  1. Department of Forensic Medicine, Medical Faculty, Tehran University of Medical Sciences, Tehran, Iran
  2. Prosar International Poison Center, St. Paul, MN
  3. Department of Experimental and Clinical Pharmacology, The University of Minnesota College of Pharmacy, Minneapolis, MN, USA

Address for Correspondence

Seyed Mostafa Mirakbari
3rd floor, No.87, Davood Asadi St.
Shahid Rahimi St. 14518
First square of sadeqi-yeh
Tehran, IRAN
Phone/Fax: +98(21)4230234
E-mail: mostafa54540@hotmail.com

Introduction

The number of adult poisonings in Iran continues to increase, with approximately 20,000 patients referred annually to our hospital1,2,3. The purpose of this study was to determine the epidemiology of poisonings referred to our poison control center from April 25, 2000, to April 25, 2001, with emphasis on the types of agents involved, symptoms associated with the exposures and the reasons for exposure. Other data examined included patient disposition, routes of exposure, and past medical history.

Methods

All patients with a suspected poisoning that were referred to our center were entered into the study. Staff emergency department physicians were provided with a questionnaire and performed a standardized assessment of the patients including history of exposure. A psychiatric evaluation was performed on all admitted patients. Data were analyzed using SPSS software (SPSS Sciences, Chicago, IL).

Results

Nineteen thousand, five hundred eleven patients were enlisted in the study. Eight thousand two hundred eighty-four patients (42.5%) were admitted to the hospital and 11,227 were discharged after 3-6 hours of observation and management. Of the patients admitted to the hospital, 1,160 (14.01%) were admitted to the ICU. One thousand seventy-seven (5.52%) patients were intubated regardless of disposition. Twelve thousand, two hundred thirty-three patients (62.7%) were female and 7,278 (37.3%) were male. Age groups and sex of patients is presented in Table 1.

Marital status was also examined. Concerning females, 6,606 (54%) were single, 4,832 (39.5%) were married and status was unknown in 6.5% of patients. For males, 4,440 (61%) were single, 2,620 (36%) were married, and status was unknown in 3%. Past medical history revealed that 18,262 (93.6%) patients had no prior history of psychological disorders whereas such a history was present in 1,249 (6.4%) patients. Of the patients with a history of psychological disorders, 985 (79%) involved anxiety and depression. Other medical conditions recorded included diabetes mellitus in 63 (0.32%), cardiovascular disease in 183 (0.94%) and epilepsy in 59 (0.3%).

A relatively symmetric distribution was seen when examining the incidence of poisonings with respect to the seasons of the year. 5,412 (27.7%) occurred in summer followed by 5,123 (26.2%) in spring, 4,724 (24.3%) in winter, and 4,254 (21.8%) in fall.

Pharmaceuticals were involved in 13,004 (66.6%) of cases, whereas non-pharmaceuticals were involved in 6,507 (33.4%). The types and incidence of agents involved in all cases are presented in Table 2. The categories of agents were determined by history or by agent packaging. In cases of suspicious poisoning with a poor history or no packaging, samples were sent to an outside laboratory for analysis.

The analgesic category was broken down further into more specific agents: acetaminophen (31.4%), aspirin (6.07%), diclofenac (5.72%), ibuprofen (5.14%), mefanamic acid (4.2%), indomethacin (0.86%), adult cold formulations (18.1%), mixed ingestions (28.5%).

The reasons for poisoning are listed below in Table 3, with the vast majority being voluntary in nature. Routes of exposure are listed in Table 4, with oral poisonings predominating. Table 5 lists the percentage of patients who experienced a decreased level of consciousness after exposure to a given agent. Antipsychotic medications were most often responsible for a decreased level of consciousness.

Tables 6 lists the various symptoms noted by organ system. Gastrointestinal symptoms were most common. Table 7 describes the level of consciousness observed in patients with respect to exposure to a given class of agents.

Discussion

In 1991, 12,004 patients with a poison exposure were referred to our center. Of these, 5,786 (48.2%) were admitted to a hospital ward and 6,218 (51.8%) were discharged after evaluation. Our study demonstrated an increase of 62.5% in the number of patients presenting with a poison exposure. The number of cases admitted to a hospital ward increased 43.2% since 1991 to 8,284. The majority of the patients (15,528 – 80.1%) in our most recent study were 13-40 years of age and within this group those 20-30 years old constituted the largest portion (6,770 – 34.7%). Reasons for the higher incidence in this 13-40 year old group may include problems associated with marriage and financial difficulties, overpopulation, and activities undertaken by this group in both social and occupational settings that lead to poisoning. The decrease in incidence of poisonings after 40 years of age may be attributed to a smaller population base for this age group, a greater capacity to deal with everyday stresses of life, and an overall lower incidence of suicide attempts in this age group.

The most common pharmaceutical agents involved in poisonings were benzodiazepines (16.4%), analgesics (12.65%) and antidepressants (11.8%). The number of opiate exposures increased compared to earlier unpublished reports from our center. In 1991, only 727 (6.05%) involved opiates compared to 2,165 (11.5%) for our present study. Intentional (voluntary) poisoning was the most common reason for poisoning (18,282 - 93.7%) with suicide attempts accounting for 12,762 (65.4%) of this group. The incidence of poisoning by pesticides is less than that reported in similar studies4 and we hypothesize that this is most likely due to the greater availability of other poisoning agents. The lower incidence of carbon monoxide poisoning we report in comparison to other studies5 is due primarily to architectural differences in home design, as more homes in our country are open to outside air. Also contributing to this lower incidence is the fact that carbon monoxide-related deaths occurring prior to hospital admission were not reported in this study as these are typically referred to our forensic toxicology center and reported through this center. The greatest percent of cases demonstrating a depressed level of consciousness (54.3%) was noted with exposures to antipsychotics either as sole agent of exposure or in combination with other antipsychotics.

Our center has a mortality rate of 0.96% associated with poisoning cases. The low rate may be due to the fact that deaths from poisonings that occur prior to arrival at our center were not used in calculating the rate. The majority of deaths due to poisonings in Tehran involve illicit opiate overdose and these are reported through our forensic toxicology center.

In conclusion, we present an etiological overview of poisonings seen at our center. To reduce the number of poisonings occurring we suggest that an emphasis be placed on primary healthcare programs which focus on suicide prevention and poison education.

Table 1. Patient age and sex

Age group

Number of male
patients

Number of female
patients

Total

13 - 20 1228 (22%) 4352 (78%) 5580 (29.5%)
21 - 30 2823 (41.7%) 3947 (58.3%) 6770 (34.6%)
31 - 40 1380 (42.1%) 1898 (57.9%) 3278 (16.8%)
41 - 50 760 (46.4%) 879 (53.6%) 1639 (8.4%)
>51 1067 (47.59%) 1177 (52.41%) 2244 (11.5%)

Table 2. Incidence of poisonings based on type of agent

  Agent Percent Number
1 Benzodiazepines 16.4 3200
2 Multi drug ingestions or unknown agent1 12.84 2505
3 Analgesics 12.65 2468
4 Antidepressants 11.8 2302
5 Opiates2 11.2 2165
6 Alcohols 4.8 937
7 Cardiovascular drugs 4.6 898
8 Antipsychotics 4.1 800
9 Anticonvulsants 3.7 722
10 Pesticides3 3.36 656
11 Arsenic4 2.8 546
12 Rodenticides 2.6 507
13 Petroleum distillates and Turpentine 1.82 355
14 Detergents 1.4 273
15 Gases 1.25 244
16 Hallucinogens 1.2 410
17 Bites (insect, snake, scorpion) 0.8 176
18 Mushrooms and poisonous plants 0.7 136
19 Corrosive 0.68 132
20 Iron 0.4 78

1 In these cases either the agent was unknown or in cases of co-ingestion, the clinical findings could not be attributed to a specific drug(s).

2 Includes only abused opiates (e.g. opium and heroin)

3 Organophosphates: 407 (62.1%), carbamates: 138 (21%), organochlorines: 54 (8.2%), unknown: 57 (8.7%)

4 Arsenic is used in depillatory powders.

 

Table 3. Reasons for poisoning

Nature of poisoning Percent Number
Voluntary1 93.7 18,282
Accidental2 4.86 948
Occupational3 1.38 269
Criminal 0.06 12

1 Voluntary includes all cases of intentional ingestions whether or not a suicidal intent was established. This was determined by the treating physician.

2 Agents involved in the accidental poisonings group were: carbon monoxide and other gases, 242 patients (25.5%); petroleum distillates and turpentine, 218 patients (23%); opiates, 180 patients (19%); bites, 176 patients (18.6%); and other substances, 132 patients (13.9%).

3 The majority of occupational exposures to poisons are managed at occupational medicine clinics onsite at large manufacturing facilities.

 

Table 4. Routes of Exposure

Route Number of cases
Oral 18,638 (95.5%)
Inhalation 399 (2.05%)
Injection 291 (1.49%)
Bite 176 (0.9%)
Dermal1 7 (0.034%)

1 Most visits for dermal exposures are evaluated in the dermatology or emergency departments rather than in the poison control center, explaining the low frequency of dermal exposures reported here.

 

Table 5. Percent of patients developing decreased level of consciousness

Agent Percent
Antipsychotics 54.3
Opiates 49
Anticonvulsants 36
Gases 36
Alcohols 32.2
Benzodiazepines 24
Multi drug ingestions or unknown agent 18.5
Antidepressants 17.1
Mushrooms and poisonous plants 16
Corrosives 12
Cardiovascular drugs 10.5
Analgesics 9.5
Petroleum distillates and Turpentine 9.5
Pesticides 9.4
Hallucinogens 9
Rodenticides 6
Bites (insect, snake, scorpion) 6.5
Arsenic 4.8
Detergents 2
Iron 1.3

Table 6. Signs and symptoms by organ system

Organ System Sign/Symptom Number of cases Percent of cases
Gastrointestinal Nausea 5,853 31 %
  Vomiting 2,771 14.2 %
  Abdominal Pain 1,225 6.3 %
  Salivation 605 3.1 %
  Diarrhea 297 1.5 %
  Hematemesis 41 0.21 %
Respiratory Bradypnea (RR<8) 1,776 9.1 %
  Tachypnea (RR >12) 889 4.6 %
  Respiratory Distress 204 1.05 %
  Respiratory Arrest 47 0.24 %
Ophthalmic Miosis 2,380 12.2 %
  Mydriasis 1,803 9.24 %
  Blurred vision 1,206 6.2 %
  Nystagmus 16 0.08 %
Neurological Decreased DTRs 2,166 11.1 %
  Increased DTRs 1,641 8.41 %
  Convulsions 39 0.2 %

Table 7. Level of consciousness in poisonings

Agent Conscious Grade I* Grade II* or higher
Benzodiazepines 2432 (76%) 541 (16.9%) 229 (7.1%)
Analgesics 2233 (90.5%) 161 (6.5%) 74 (3%)
Opiates 1104 (51%) 629 (29.05%) 432 (19.95%)
Antidepressants 1908 (82.9%) 255 (11.1%) 138 (6%)
Hallucinogens 374 (91%) 26 (6.5%) 10 (2.5%)
Cardiovascular drugs 804 (89.5%) 85 (9.5%) 9 (1%)
Antipsychotics 366 (45.7%) 256 (32%) 178 (22.3%)
Alcohols 635 (67.8%) 169 (18%) 133 (14.2%)
Petroleum distillates & turpentine 335 (90.5%) 18 (5%) 2 (0.5%)
Pesticides 594 (90.6%) 52 (0.8%) 10 (1.4%)
Anticonvulsants 462 (64%) 166 (23%) 94 (24%)
Gases 156 (64%) 29 (12%) 58 (24%)
Detergents 268 (98%) 5 (2%)
Corrosives 120 (88%) 16 (12%)
Poisonous plants 114 (84%) 22 (16%)
Iron 77 (98.7%) 1 (1.3%)
Rodenticides 477 (94%) 30 (6%)
Arsenic 520 (95.2%) 26 (4.8%)
Bites 164 (93.5%) 11 (6.5%)
Poisoning of unknown origin 1663 (81.5%) 364 (18.5%)

*Based on the Reed Coma Classification. 9

References

  1. Pajoomand A, Shari-ate torbaqani A. Diagnosis and Management of Poisonings;1st edition (Persian).Tehran:CHEHR;1998.p. 1-640.

  2. McAleer J, Murphy GJ, Taylor RH, Moran JL, O’Connor FA. Trends in the severity of self-poisoning. J R Soc Med 1986;79:74-5.

  3. Haddad ML, Shannon MW, Winchester JF. Clinical Management of Poisoning and Drug Overdose. 3rd edition. Philadelphia: W.B. Saunders, 1998. p. 2-31.

  4. Senanayake N, Peiris H. Mortality due to poisoning in a developing agricultural country over 20 years. Human Experimental Toxicol 1995;14:808-811.

  5. Liu Y, Wolf LR, Zhu W. Epidemiology of adult poisoning at China Medical University. J Toxicol Clin Toxicol 1997;35:175-80.

  6. Dorado-pombo S, Martin-fernandez J, Sabugal-rodelgo G, Caballero-valles PJ. Epidemiology of acute poisoning: study of 613 cases in the community of Madrid in 1994. Rev Clin Esp 1996;196:150-6.

  7. Goldacre M, Hawton K. Repetition of self-poisoning and subsequent death in adolescents who take overdoses. Br J Psychiatry1985;146:395-8.

  8. Bouknight RR, Alguire PC, Lofgren RP, Hoppe RB. Self-poisoning: Outcome and complications in the community hospital. J Fam Pract 1986;23:223-5.

  9. Reed CE, Driggs MF, Foote CC. Acute barbiturate intoxication. A study of 300 cases based on a physiologic system of classification of the severity of intoxication. Ann Intern Med 1952; 37: 390-396.

 



Journals Home  | Past Issues | Search | Send Comments to ACMTNet

Copyright 1999-2003, American College of Medical Toxicology.