Introduction

Paracetamol is a commonly used medicine. It is widely available, cheap and usually safe when taken correctly. Paracetamol is used in suicide attempts. Overdose is a frequent cause of hospital admission on both sides of the Atlantic where it is the most common identifiable cause of fulminant hepatic failure.^{3, 4, 5}
The aims of this study were to establish whether hospital admissions due to paracetamol overdose in Ireland dropped when the IMB revised conditions for the supply and sale of paracetamol in 1997 and to determine compliance of non-pharmacy outlets with the conditions.

Methods

Data on hospital admissions were obtained from the Hospital Inpatient Enquiry System (HIPE). One hundred non-pharmacy outlets in Dublin were surveyed to determine compliance with the IMBs conditions. The outlets, selected arbitrarily, were in the main residential / shopping areas. In each outlet a researcher attempted to buy two packs of any paracetamol product containing 24 tablets or four packs containing 12 tablets i.e. four times more than the conditions of sale stipulate. Four packs of 12 tablets were sought when packs of 24 tablets were not available.

Results

Paracetamol overdose was the main reason for hospital admission due to poisoning between 1993 and 1999, responsible for one-quarter of all poisoning admissions.
 

Hospital admissions from paracetamol overdose increased by 29% between 1993 and 1999, Table 1a. Females had almost twice as many admissions as males. The admission rate per 100,000 population increased from 31.1 to 38.3, Table 1b. The rate of increase was more than twice as high in females than males. The mean length of hospital stay was 2.5 days (1 to 149 days). Admissions dropped by only a 1.9% since IMB conditions were revised in 1997.
 

HIPE data were 99% complete regarding poisoning intent except in 1998 and 1999 which were 94.8% and 92.2% complete respectively. Between 1993 and 1999 the proportion of overdoses that were intentional rose from 54.4% to 72.3% (female increase: 56.3% to 74.1%; male increase: 51.1% to 68.6%). Approximately 50% of intentional overdose admissions were in the 15-24 age group. Intentional overdose was unusual in children and over 65, Figure 1.

Though the most common age group for accidental paracetamol poisoning was also 15-24, the pattern of accidental poisoning differed from intentional overdose, as children under the age of 5 accounted for approximately 20% of admissions, Figure 2.

Purchases of 48 paracetamol tablets (either 2 x 24 packs or 4 x 12 packs) were successfully made in each shop, Table 2. In three shops a sales assistant commented on the researchers presumed poor health and one hesitated when asked for 4 packs of paracetamol but did not comment. No retail outlet displayed the IMBs conditions of sale nor information on paracetamol dangers. All tablets were sold in blister packs.
 

The quantity and variety of paracetamol on sale reflected the size of the shop. Large supermarkets stocked a wide variety of paracetamol products in pack sizes of 24 tablets and displayed them prominently in the cosmetics section. Smaller shops generally stocked a 12-tablet pack, had a smaller variety of products but often 2-3 different types. In petrol stations paracetamol was usually limited to one or two product types, available as a 12 pack, and in some cases these were stored behind the counter.

Discussion

Paracetamol poisoning is a serious public health issue. It is the main drug used in self-poisoning⁶ and the most common cause of hospital admission from poisoning in Ireland. It is a concern that admissions increased by 29% since 1993 as most cases are young people.

Paracetamol poisoning is related to its availability⁶. There is a strong positive association between sales trends and non-fatal overdose. Ready availability was associated with 43% of hospital admissions from self-poisoning in the UK⁷. In the US, paracetamol accounted for 4.1% of deaths from poisoning reported to American Poisons Centres in 1997⁸ and most were deliberate self-poisonings. Reduction in the quantity of paracetamol available as a single purchase might reduce suicide and paracetamol related liver failure⁹.

Young people commonly and naively take paracetamol in suicide gestures^10,11. They lack insight of the serious complications associated with misuse and they underestimate the potential for toxicity. One study of 569 adolescents found that 42% felt that paracetamol could do no harm and 50% overestimated the fatal dose¹⁰. These findings together with the wide availability of paracetamol were considered to contribute to its frequent use in adolescent suicidal behaviour¹².

Gazzard found that none of the 48 patients they interviewed would have taken paracetamol had they known of the 2-3 day interval before the onset of serious symptoms and only five received the drug on prescription¹³.

The IMBs (1997) conditions for the sale and supply of paracetamol were designed to reduce the incidence and consequences of overdose. These conditions, without statutory backing, have little influence on sales from non-pharmacy outlets, as seen by the mere 1.9% reduction in admissions sine 1997. The IMB conditions are being ignored as:

1. Sales in excess of the guidelines (12 tablets) are easily made
2. Large supermarkets sell packs of 24
3. Supermarkets display large quantities and a varieties of paracetamol
4. Stocks are not limited to emergency supplies.

We acknowledge the support of the Economic and Social Research Institute in providing HIPE data and of the Irish Medicines Board for their valuable advice.

Correspondence:

Laffoy Mariearie,
Department of Public Health,
Eastern Regional Health Authority,
Dr. Steevens Hospital,
Dublin 8.
Telephone: 00 353 1 6790700.
Fax: 00 353 1 6710606

References

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2. Drug Safety Newsletter; Notification of changes in availability of OTC medicines; Paracetamol. Irish Medicines Board. 1997; 4: May 1997
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