Page last updated: 31-MAR-2009

Drugs Indicated for the Treatment of Obesity

March 2009

Introduction

This page contains data on the prescribing of drugs used in the treatment of obesity as defined in British National Formulary (BNF) section 4.5, in Scotland for the financial years 1998/99 to 2007/08, inclusive. Statistics shown include prescribing volume, as measured by the number of prescribed items and defined daily dose, and the gross ingredient cost, at both Scotland and NHS Board level.

Obesity is not just a cosmetic issue. It increases the risk of many health problems such as:

  • Type 2 Diabetes
  • Heart Disease
  • Stroke
  • Back and Joint Pain
  • High Blood Pressure
  • Gall Stones
  • Fatty Liver
  • Infertility
  • Breathlessness
  • Osteoarthritis
  • Sleeplessness
  • Depression
  • certain Cancers

The Department of Health and the Medical Research Council first raised it as a public health problem in a joint report in 1974 1. Further evidence of health problems associated with obesity was produced in 1983 in a report from the Royal College of Physicians (London) 2.

The Scottish Office, Department of Health issued a report in 1996 3 which identified obesity as a contributory factor in coronary heart disease. Another report on the Scottish diet 4 highlighted obesity as a growing problem of relevance to the high rates of non-insulin-dependant diabetes mellitus (NIDDM), hypertension and hypercholesterolaemia in Scotland.

An accepted measure of obesity is the Body Mass Index (BMI), calculated as:

BMI Formula

For example, an adult of 70 kg with a height of 1.75 m has a BMI of:

70/1.752 = 22.9

The internationally accepted ranges 5 of BMIs are given in the following table:

Underweight under 18.5
Normal

18.5 - 24.9
Overweight 25.0 - 29.9
Obesity 30.0 - 39.9
Extreme Obesity => 40


The main treatment of the obese individual is a suitable diet, carefully explained and fully supported, coupled with a change of lifestyle, including increased physical activity.

The National Institute for Health and Clinical Excellence (NICE) in England and SIGN, The Scottish Intercollegiate Guidelines Network, have both issued guidelines on weight control and obesity in adults and children:

Further information on the prevalence and treatment of obesity can be found on the following internet sites:

Note: ISD is not responsible for the contents of external internet sites.

Obesity Drugs

Three drugs are indicated for the treatment of obesity, as described in the British National Formulary (BNF), Issue 55, March 2008, section 4.5.

  • Orlistat (Xenical®), introduced in October 1998, is an anti-obesity drug that acts on the gastro-intestinal tract, inhibiting the absorption of dietary fat. (BNF 4.5.1)
  • Sibutramine (Reductil®), introduced in June 2001, is a centrally acting appetite suppressant that inhibits the re-uptake of noradrenaline and serotonin and is used in the adjunctive management of obesity. (BNF 4.5.2)
  • Rimonabant (Acomplia®), introduced in February 2007, is also a centrally acting appetite suppressant. More specifically it is a cannabinoid receptor antagonist for the adjunctive management of obesity. (BNF 4.5.2)

Note: The European Medicines Agency (EMEA) recommended the suspension of the marketing authorisation for Rimonabant (Acomplia®) in October 2008. Marketing Authorisation for Rimonabant (Acomplia®) has since been withdrawn by the European Commission on 16th January 2009.

Summary

The prescribing of drugs used in the treatment of obesity in Scotland between 1998/99 and 2007/08 has been reviewed. A summary of the findings is given below:

  • A total of 110,324 items (76,326 for Orlistat, 28,057 for Sibutramine and 5,941 for Rimonabant) were prescribed in Scotland during 2007/08, an increase of 6,050 prescribed items over the previous year 2006/07.
  • Prescribing of Rimonabant increased by 151.30% in 2007/08 over the previous year 2006/07, however Rimonabant only accounted for 5.40% of the total prescribing of Obesity Drugs in 2007/08.
  • Expenditure on Obesity Drugs reduced from £4.89 million to £4.54 million between 2006/07 and 2007/08.
  • It is estimated that 0.23% of the population aged 12 and over, that is, around 10,263 people, make daily use of Orlistat, Sibutramine and/or Rimonabant. It must be emphasised that this is an estimate; the actual patient base is unknown at present.

Data Source

Practitioner Services, a division of NHS National Services Scotland, processes all NHS prescriptions for payment of pharmacies, dispensing doctors and appliance suppliers. This gives a full record from which trends in prescribing can be investigated at a detailed level. The data includes prescribing by GPs, nurses, dentists, pharmacists and hospitals, where the latter was dispensed in the community. Hospital dispensed prescriptions are NOT included in the figures. Information Services Division (ISD) cannot say what proportion of the dispensed drug is actually consumed.

A Microsoft Excel spreadsheet is provided that gives both the data behind the graphs and for individual drugs in BNF section 4.5.

link to a microsoft excel file  Drugs Used in the Treatment of Obesity, 1998/99 - 2007/08

Prescribing Statistics - Scotland

Figure 1 shows the number of prescribed items by individual drug and in total for drugs used in the treatment of obesity in Scotland from 1998/99 to 2007/08.

Figure 1 - Number of Prescribed Items - Scotland 1998/99 to 2007/08

Figure 1 - Number of Prescribed Items - Scotland 1998/99 to 2007/08

Source: Prescribing Information System, ISD Scotland
Note 1: Excludes prescribed items that were not dispensed.

Increased awareness of the adverse health effects of obesity are demonstrated by Figure 1, where the prescribing of "Obesity Drugs" is more than twenty-five times higher in 2007/08 than it was in 1998/99, with the largest increase occurring between 2000/01 and 2001/02. Orlistat is approximately three times more likely to be prescribed than the appetite suppressant, Sibutramine.

ISD cannot say how many people are receiving these drugs. However, an approximation can be found from using the Defined Daily Dose (DDD) as developed by the World Health Organisation (WHO). The DDD is defined as the "assumed average maintenance dose per day for a drug used on its main indication in adults". DDDs are derived from the international use of the substance in question. As British prescribing patterns may differ from the accepted international value, each DDD should be regarded as a technical value, a close approximation of an average of the actually used doses. The DDDs are not necessarily the most frequently prescribed or used doses.

The WHO DDD for the two drugs indicated for the treatment of obesity are:

  • Orlistat - 360mg, administered orally
  • Sibutramine - 10mg, administered orally
  • Rimonabant - 20mg, administered orally

Figure 2 shows the Defined Daily Dose given as the number of DDDs per 1,000 population per day. This value offers an explanation of what proportion of the population may receive a certain drug treatment. For example, an estimated drug consumption of 10 DDDs per 1,000 population per day corresponds to a daily use of the drug by 1% of the population. Mid-year population estimates produced by the General Registrar Office for Scotland have been used in these calculations. The population has been restricted to persons aged 12 and over.

Figure 2 - Number of DDDs per 1000 Population (aged 12 to 90 and over) per Day 1998/99 to 2007/08

Figure 2 - Number of DDDs per 1000 Population (aged 12 to 90 and over) per Day 1998/99 to 2007/08

Source: Prescribing Information System, ISD Scotland

The prescribing pattern exhibited in Figure 2 is similar to that of Figure 1, with Orlistat being the most commonly prescribed drug. The graph indicates that 0.23% of the population, that is around 10,263 people aged 12 and over, make daily use of drugs indicated for obesity. It must be emphasised that that these figures are estimated; the actual patient base is unknown.

Figure 3 - Gross Ingredient Cost (£m) - 1998/99 to 2007/08

Figure 3 - Gross Ingredient Cost (£m) - 1998/99 to 2007/08

Source: Prescribing Information System, ISD Scotland

The total Gross Ingredient Cost for drugs indicated for the treatment of obesity reduced from £4.89 million to £4.54 million between 2006/07 and 2007/08. This reduction is due to a fall in the price of these drugs.

The cost per defined daily dose (DDD) for 2007/08 is £1.21 or £443 per annum, down 13.20% on the previous year. Taking the GRO mid-year population estimate for 12 years old and over, the cost per head is calculated as £1.02 in 2007/08.

Prescribing Statistics - NHS Boards

The following charts, for reasons of clarity, use the NHS Boards? ciphers rather than the full NHS Boards? names. Table 1 maps the cipher to the NHS Board name.

Table 1 - NHS Board Cipher - Translation

NHS Board Cipher NHS Board Name
A NHS Ayrshire and Arran
B NHS Borders
F NHS Fife
G NHS Greater Glasgow and Clyde
H NHS Highland
L NHS Lanarkshire
N NHS Grampian
R NHS Orkney
S NHS Lothian
T NHS Tayside
V NHS Forth Valley
W NHS Western Isles
Y NHS Dumfries and Galloway
Z NHS Shetland


Source: Prescribing Information System, ISD Scotland

Please note that NHS Argyll and Clyde ceased to exist as a single entity from April 2006. Argyll and Bute was absorbed into NHS Highland and the remainder into NHS Greater Glasgow to become NHS Greater Glasgow and Clyde.

Usage

The number of DDDs per 1000 population per day has been used to permit comparison in the prescribing of drugs indicated for the treatment of obesity between NHS Boards, as shown in Figure 4.

Figure 4 - DDDs per 1,000 Population (aged 12 and over) per Day by NHS Board 1998/99 & 2007/08

Figure 4 - DDDs per 1,000 Population (aged 12 and over) per Day by NHS Board 1998/99 & 2007/08

Source: Prescribing Information System, ISD Scotland
Note 1: Data for NHS Greater Glasgow and Clyde and NHS Highland in 1998 represents the 'old' health board structure of Greater Glasgow health board and Highland health board. Data for 2006/07 represents the new formation of these boards, to incorporate the parts of Argyll and Clyde from April 2006.
Note 2: Scotland averages exclude data where the NHS Board was unknown.
Note 3: Data are estimated; the actual patient base is unknown at present.

Three NHS Boards, Western Isles (W) , Lanarkshire (L) and Fife (F) make the greatest use of drugs indicated for obesity. It is estimated that 0.4% of the target population in NHS Western Isles, 0.29% in NHS Lanarkshire and 0.27% in NHS Fife, that is around 93, 1,389 and 839 people respectively, make daily use of such drugs. This contrasts with NHS Borders (B) and NHS Orkney (R) where only 0.08% and 0.13% of their respective target populations aged 12 and over (81 and 23 people respectively) use either Orlistat, Sibutramine, Rimonabant or a combination of the three. It must be emphasised that this is an estimate; the actual patient base is unknown at present.

Costs

Figure 5 shows the Gross Ingredient Cost of drugs indicated for obesity per head of population (aged 12 and over) has increased from an average of £0.04 in 1998/99 to £1.01 by 2007/08.

Figure 5 - Gross Ingredient Cost (£) per Head of Population (aged 12 and over) by NHS Board 1998/99 & 2007/08

Figure 5 - Gross Ingredient Cost (£) per Head of Population (aged 12 and over) by NHS Board 1998/99 & 2007/08

Source: Prescribing Information System, ISD Scotland
Note 1: Data for NHS Greater Glasgow and Clyde and NHS Highland in 1998 represents the 'old' health board structure of Greater Glasgow health board and Highland health board. Data for 2006/07 represents the new formation of these boards, to incorporate the parts of Argyll and Clyde from April 2006.
Note 2: Scotland averages exclude data where the NHS Board was unknown.
Note 3: Data are estimated; the actual patient base is unknown at present.

NHS Western Isles (W), NHS Lanarkshire (L) and NHS Fife (F) have the highest cost per head for drugs indicated for obesity, at £2.03, £1.28 and £1.20 respectively. This contrasts with NHS Borders (B) and NHS Orkney (R) where the cost per head is £0.37 and £0.60 respectively. In total, nine NHS Boards spend more than the Scottish average of £1.01 per head of population aged 12 and over. It must be emphasised that this is an estimate; the actual patient base is unknown at present.

References

  1. DHSS/MRC Research on Obesity, London, HMSO 1974 
  2. Royal College of Physicians Obesity. A Report by the Royal College of Physicians. Journal of Royal College of Physicians, London 1983; 17 pp 58 
  3. Scottish Office Department of Health. Coronary heart disease in Scotland. Report of policy review. Edinburgh:The Department of Health 1996 
  4. Scottish Office Home and Health Department. The Scottish Diet. Scotland's health: a challenge to us all. Report of a Working Party to the Chief Medical Officer for Scotland. Edinburgh: The Department of Health, 1993 
  5. Obesity in Scotland, Integrating Prevention with Weight Management. Scottish Intercollegiate Guidelines Network (SIGN), Pilot Edition, November 1996, p3 

Main contact: Email Prescribing