How many people use retail analgesics? [December 2002; 106-6]

How many people use retail analgesics?
What analgesics are being used? Paracetamol overdoses affected? Comment A number of issues come together to focus on what analgesics people use for common conditions, like headache, colds, aches and pains or period pains. One is safety, with paracetamol poisoning being a major driver in restricting pack size since 1998 in the UK. Another is increased concentration on the safety of aspirin and ibuprofen. A third would be the recognition that the vast majority of people use retail analgesics sensibly, and derive much benefit.

Almost any discussion of any of these topics raises the question of how many people use retail analgesics, and what sort, and how much. Satisfactory answers are few.

How many people use retail analgesics?

Bandolier 52 reported on a random sample of the Swedish population aged 16 years and older, who were asked specific questions relating to analgesic use [1]. The participation rate was 79%, and information was available from just under 12,000 people.

Overall about 20% of men and 30% of women used non-prescription analgesics. Use of non-prescription analgesics was similar in all age groups. There were some fairly obvious relationships. For instance, headache and musculoskeletal pain were associated with increased use of analgesics, as were high levels of physical work stress, poor physical fitness and perceived poor health. In the previous 12 months, 13% of men and 20% of women had visited alternative therapists.

What analgesics are being used?

Annual sales of paracetamol, aspirin and ibuprofen, both by weight, pack, and pack size have been reported from a source (IMS Health) with census data on all wholesale sales to pharmacies and other retail outlets in the UK and Northern Ireland [2].

The total annual weight sold (in tonnes) is shown in Table 1 for 1998, 1999 and 2000. Of course, that's not quite the same as tablets, and the equivalent in 500 mg paracetamol, 300 mg aspirin and 200 mg ibuprofen tablets is shown in Figure 1. The information for aspirin is amended for the approximately 40% sold as 75 mg tablets (that's about 80 million 75 mg tablets in 2000).

Table 1: Tonnes of retail analgesics sold each year in UK and NI

Year	Paracetamol	Aspirin	Ibuprofen
1998	409	66	26
1999	199	22	30
2000	166	15	46

Figure 1: Standardised retail tablet sales in UK and NI

That works out to a reduction in analgesic use. Paracetamol use reduced significantly. Taking the UK adult population (over 12, say) to be about 51 million, on average each adult used 21 tablets in 1998, and 12 tablets each year in 1999 and 2000. The balance changed from a preponderance of paracetamol in 1998 to a rough parity between paracetamol 500 mg and ibuprofen 200 mg tablets in 2000. If about one adult in four uses retail analgesics, the total number of analgesic tablets for those who used them would be about 50 per year.

Paracetamol overdoses affected?

Table 2 shows the immediate effects of restricting paracetamol pack size. Most show reduction in some aspect of paracetamol poisoning, though little effect was seen in Belfast. The largest and most through study showed a reduction by 21% in deaths from paracetamol overdose when taken alone compared with the average of the previous two years, down from about 190 to 150 cases a year for paracetamol alone [3]. It also showed reduced presentations, and admissions to transplant units and liver transplants.

Table 2: Summary of studies on paracetamol use and overdose after legislative change in UK and NI

Reference	Population	Measures	Outcomes

Prince et al. Lancet 2000 355: 2047-2048	Newcastle and UK	Referrals to liver unit and UK transplant lists before and after September 1998, to December 1999	Fall in referrals because of paracetamol overdose from 2.5 to 1 per month, and in UK Transplant Authority from 3.5 to 2 per month
Turvil et al. Lancet 2000 355: 2048-2049.	London	Incidence of paracetamol overdoses from Sept 1995 to August 1999	21% reduction in all paracetamol overdoses and 64% reduction in severe overdoses
Robinson et al. BMJ 2000 321: 926-927.	Belfast	Incidence of paracetamol overdose January-June 1998 and 1999	No change in numbers of overdoses, admissions or severe liver failure, but reduced quantity taken and average serum paracetamol lower at 4 hours
Hawton et al. BMJ 2001 322: 1-7.	Five UK liver units and seven general hospitals, and England & Wales	Mortality, admissions, transplants, 24 months before and 12 months after change in legislation	Reduced number of deaths from paracetamol (21%), reduced admissions to transplant units, patients listed for transplant and transplantations due to paracetamol overdose, reduced number of overdoses due to paracetamol

Comment

Discovering how consumers use retail analgesics is hardly easy, especially when markets are perturbed by legislation. The pack size restrictions introduced in September 1998 had effects before and after that date. Manufacturers had a year to change their manufacturing and distribution practices. Consumers may have bought supplies in advance of the legislation. Travel changes purchasing patterns, and visitors to the USA often return with large pots of paracetamol or ibuprofen, because it is available in large amounts at much lower cost.

What we can say is that consumer usage of paracetamol has dropped substantially, by more than half since 1998. Overdose statistics seem to reflect that change, but are available only from the first year after the change. Several more years will be needed to see the full effects.

Ibuprofen use has doubled. While ibuprofen overdose is not so much of a problem, the insidious nature of NSAID adverse events may mean that some of the more enthusiastic users could be putting themselves at risk, particularly from gastrointestinal problems.

Quantifying that risk is difficult. It is a tricky area, the literature is confused, and practice changes (like getting paracetamol on prescription because it is now expensive). Bandolier will revisit as more information comes our way.

References:

KIM Antonov, DGL Isacson. Prescription and nonprescription analgesic use in Sweden. Annals of Pharmacotherapy 1998 32: 485-94.
CL Sheen et al. Paracetamol pack size restriction: the impact on paracetamol poisoning and the over-the-counter supply of paracetamol, aspirin and ibuprofen. Pharmacoepidemiology and Drug Safety 2002 11: 329-331.
K Hawton et al. Effect of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the UK: before and after study. BMJ 2001 322: 1-7.

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How many people use retail analgesics?