UK Opiate Usage, Consumption, Attitudes and Prices

Combined Results of IDMU Surveys 1994-2002

1.       Heroin

1.1       Consumption - The Literature

1.1.1    There are many different estimates of the amount of heroin consumed by dependent users.  Few of these can be regarded as entirely reliable, as the amounts and purities of the drug seized can vary considerably.  Most of the research into heroin consumption in the UK was conducted in the mid-1980s.

1.1.2    In 1987, Parker et al [1] reported that  users consumed between 2 "bags" of heroin per day (about £10) and one gram (£60), with the majority consuming between one quarter and one half gram. Caplin & Woodward [2] in a survey of problem drug users conducted by the BBC, found that 39% of the heroin users they surveyed reported spending over £250 per week on the drug.  This would have been the rough equivalent of 0.6g of heroin per day (@£60 per gram). The Institute for the study of Drug Dependence (ISDD) [3] suggested that a dependent user is likely to take one quarter gram per day, although they did not state the source from which this estimate is derived.

1.1.3    In 1988, Gossop et al [4] found that, for users of heroin by injection 70% used less than 0.5g per day, 19% used 0.5g-0.75g, and 11% used over 0.75g per day. Two thirds (66%) of chasers (inhalers) used under 0.5g per day, 12% used 0.5g to 0.75g, and 22% used over 0.75g per day.  The same team reported in 1992 [5]   that current heroin users would consume  between 0.06g and 5g per day, with 23% using 1g per day or more. Parry [6] , in criticising maintenance prescribing at levels of 100mg (pharmaceutical diamorphine), suggested that daily prescription of 300-400mg would normally be needed to prevent an addict "topping up" from illicit sources, and that few users would consume more than 500-600mg per day even if free access were allowed.  These quantities would be the equivalent of 0.6g-1.8g of street heroin, at 30-50% purity [7] . In an autobiographical account, Stewart [8] stated that addicts will use 'at least £20 to £60 per day (1/4g for £20)', and that some 'users can smoke 2-3 grams a day costing up to £70 each.'

1.1.4    Assessing the actual level of opiate dependence is fraught with difficulties, primarily concerning the perceived reliability of self-report accounts of usage, and the unknown purity levels of street drugs.  Higgins et al [9] proposed that testing pupillary response to a challenge dose of methadone would provide an objective marker, as response was lowest in heroin addicts claiming the heaviest and most prolonged levels of dependent use.

1.2       Case Histories

1.2.1    I have examined medical reports of a number of registered heroin addicts in the course of court cases, and have noted individuals being prescribed in excess of 300mg of pharmaceutical (injectable) diamorphine per day, equivalent to the amount contained in around a gram of street heroin.  Many registered addicts supplement their prescriptions with street heroin, indicating yet higher levels of use. 

1.2.2    A recent case involved detailed accounts of an alleged heroin supply conspiracy in the North of England [10] . A total of 782 transactions were recorded, involving a nominal 477.45g and £17,554, over 90 regular customers plus a number of individuals whose name appeared once.  The average (mean) deal size was 0.6g, with an average price paid of £22.15.  Some customers would purchase small amounts on a regular basis, other customers would buy amounts varying from 0.1g to 1/8oz (3.5g) at different times, presumably according to the funds available. Presuming these records were complete, and represented the only source of heroin for the individuals concerned, the accounts provided a unique insight into the consumption and purchasing patterns of 92 heroin addicts.  When all the named individuals and their total purchases were ranked in order, the results were as follows (table 1):

Table 1 - Heroin Use Percentiles
Percentile	10-day Use (g)	Daily Use (mg)	Pure Drug (mg)
Lower 5%	0.2	20	4
Lower 10%	0.3	30	6
Lower  25%	1.2	120	25
Median (50%)	2.8	280	59
Upper 25%	5.15	515	108
Upper 10%	8.95	895	188
Upper 5%	12.25	1225	257
Top 1%	26.7	2670	561

1.2.3    The most common deal sizes were 0.5g for £20 (33% of transactions), followed by 0.1g for £5 (23%), 0.2g for £10 (21%), 1g for £35 (5%), 1/16oz for £60 (6%) and 1/8oz for £110 (3%).  The name of the individual who purchased an ounce appeared only once during that period.  The median deal size was also 0.5g for £20, although half the total quantity would have been supplied in gram deals or larger.  Intermediate deal sizes would typically involve two or more units (e.g. 0.7g = .5 for £20 and .2 for £10), thus each unit of sale had a (more or less) fixed price with no further discount for multiple units.

1.2.4    Valenciano et al [11] found French intravenous heroin users injected an average of 3.6 times per day.  Perneger et al [12] , who studied daily drug administration records of 37 patients enrolled in the Geneva heroin maintenance programme, reported "The average dose of intravenous heroin was 466 mg/day; the total opiate dose, after conversion of oral opiates to heroin-equivalents, was 543 mg/day", and concluding" "Heroin users who have facilitated access to legally prescribed drugs consume about 0.5 g heroin per day."  Alvarez-Mazariegos et al [13] , studying heroin detox patients in Spain, reported "a daily average of 250 mg per day of heroin (125-1,000 mg)".  Mendis [14] reported that among 100 Sri Lankan addicts under treatment "average amount consumed was 340 mg per day.", whereas in India, Adityanjee et al [15] reported "The majority of heroin addicts were under 30 years of age (87.6 per cent), unmarried (67.6 per cent), had reached either high school or college (80.0 per cent) and reported having taken up to one gram per day (56.6 per cent) of the drug for one year or less (63.8 per cent). Heroin was mainly smoked (74.3 per cent) and in some cases inhaled, sniffed or injected."  Howe et al [16] , studying withdrawal among addicts in a laboratory setting, reported that subjects had an "average daily intake of approximately 973 mg of 92 - 98% pure heroin before entering the study."

1.3       IDMU Surveys

1.3.1    In the 1994-2002 combined IDMU surveys of recreational drug users [17] only 72 individuals  reported daily use of heroin out of a total sample of 11652 users of controlled drugs. It is unlikely that the survey - most respondents were recruited at a rural pop festivals - would have provided a representative sample of heroin users, who may have been unable to afford the entrance fee, or unwilling to leave their home area to travel to a place where supplies of the drug would be uncertain and/or expensive.  Higher levels of heroin use have been found in samples at free inner-city events.

Table 2 - Heroin User-Ratings and Monthly Spending by Frequency of Use (IDMU 1994-2002)
Frequency of use	Total Responses		Rating (0-10)		Monthly Spending
(heroin)	n	%	n	Mean	n	mean
Used Once	363	3.12%	282	3.54	24	£ 6.04
Used < 10x	292	2.51%	231	4.87	36	£ 16.46
Use < monthly	131	1.12%	106	6.00	28	£ 75.11
Use < weekly	49	0.42%	39	7.79	32	£ 34.38
Use < daily	20	0.17%	16	8.94	14	£ 110.79
Use daily	30	0.26%	28	6.75	18	£ 316.67
Several x/day	42	0.36%	34	7.38	25	£ 544.50
Ex-users	330	2.83%	249	3.34	22	£ 313.64
Would Never Use	3279	28.14%	1631	0.73	34	£ 0.00
Might Use	229	1.97%	90	3.63	5	£ 0.00
Never Heard of	33	0.28%	18	2.83	1	£ 0.00
No Response	6854	58.82%	909	1.41	10*	£ 63.80
Total Ever Used	1367	11.73%	985	4.55	199	£ 159.32
Never Used	10395	89.21%	2648	1.08	50*	£ 12.76

*  No response is generally regarded as a negative, however 181 users failing to respond to the heroin frequency question provided an age of first heroin use.

1.3.2    The average reported monthly cost of heroin for the 159 individuals who reported a positive amount (40 were for £0) was £159.32, for daily users £449.13, although 21x individuals (in the overall sample) spent in excess of £500, and eight over £1000, per month on heroin (max. £4000).   The average (including experimental and occasional users) would equate to 1 £10 "bag" every other day, and the heaviest 5% these users would be using 2-3 grams per day (bought at ounce-equivalent prices)-median £50, top 25% £250, to 10% £500, top 5% £1000, top 1% £1400).  It is noted that the user rating "marks out of 10" mirrors usage or intended usage (p<.0001), and may represent an crude but useful predictor of usage if included in the context of attitudinal studies.

Fig 1 - Weekly usage & Heroin user-ratings

1.3.2    It would therefore appear that there is a wide variation found in the amount of heroin used daily,  from one or two "bags" up to one to two grams of street quality heroin, and that users by inhalation ("tooting"or "chasing the dragon") can require considerably more heroin powder than injectors to achieve the same effect.

1.4       Heroin Purities:

1.4.1    It might be assumed that the lower down the distribution chain that Diamorphine is seized, the lower will be the purity [18] .  However, the Home Office Forensic Science Service Drugs Intelligence Unit have indicated [19] that there are no consistent differences in purity between heroin seized by the gram and by larger amounts.  If anything their results [20] suggest that gram deals tend to be purer than larger quantities, although the low sample sizes would suggest that this apparent trend, at higher levels of the market, is probably spurious. The purities of large customs seizures do not significantly exceed street purities [21] , the quarterly average purities of police and customs seizures of heroin from 1997-2001 [22] . are shown below.

1.4.2    The quarterly average purity figures for heroin powders analysed by the forensic science service in the first quarter of 1996 (the latest figures published) ranged from 44% to 45%, the typical range was last quoted in 1991, and had varied from 25%-55% [23] .  Between 1992 and 1997, the average purity of heroin powders varied on a quarterly basis within a range of 35-48% .  It is clear that the average purity of heroin powders has risen significantly in recent years.

1.4.3    Seizures analysed at the Wetherby laboratory (North East region) in the first half of 1995 [24] found the average purity to be 41.6% with an average wrap size of 82mg (approx 1/12th gram), in the second half of 1995 the Wetherby figures were 38% average purity and 133mg average wrap size.  In a statement produced in a July 1997 case at Mold Crown Court by a Chorley forensic scientist a typical heroin wrap was stated to contain between 100mg and 200mg of powder.

1.4.4    The Home Office disclosed the number and distribution of seizures of heroin at different purity levels, for illicit heroin powders examined by the Forensic Science Service during 1997.  These are reproduced in table 3 below:

Table 3 - Heroin Purity Distributions 1997 [25]
Heroin purity	Percentage of cases
Less than 5 and 5-10	2
10-20	12
20-30	21
30-40	23
40-50	23
50-60	15
More than 60	5
Police mean 35%	Customs mean 34%

1.5       UK Heroin prices

1.5.1    Heroin prices have been relatively stable since 1999, with gram prices typically between £40 and £80, falling from the £70-£90 in previous years.

Table 4 - Heroin Price Trends 1995-2002
Item	1995	1997	1998	1999	2000	2001	2002
Heroin gram Price	£83.33	£69.69	£71.25	£56.40	£60.00	£54.00	£48.54
Subjective rating (0-10)	2.9	2.7	2.2	3.0	2.4	1.8	1.4
No. reporting (heroin)	9	46	48	87	57	19	52
Total Respondents	215	1136	1153	2173	2353	681	2825

1.5.2    Prices of heroin fell significantly between 1995 and 1999, with the 1999-2001 Surveys [26] suggesting heroin prices to be relatively stable, although there is evidence of a slight fall from 2002 results with increasing numbers of respondents reporting gram prices under £40.

1.5.3    The distribution of retail prices from 1995 to 2002 are shown in fig 2 below.  The most common "bag" price is overwhelmingly £10, less commonly £20 or £5, grams typically £30-£80, with occasional reports of cheaper or more expensive deals.  There is considerable variation in ounce prices.

Fig 3 - Distribution of reported UK Heroin prices (1995-2002)

 

1.5.4    At retail level, price falls have been reflected in increased purity and in the size of £10 "bags".  In court cases involving heroin, typical bag sizes have increased from 80-120mg in the early 1990s, to 150-250mg more recently.

2.       Methadone

2.1       Introduction

2.1.1    Methadone (physeptone) is an opiate drug commonly used to counter the effects of opiate withdrawal syndromes without the euphoriant effects of heroin or morphine.  The effects of methadone are longer lasting than for heroin, such that it is common to prescribe a daily dose, whereas a heroin user would need to take the drug every 4-6 hours.

2.1.2    The prescribing of methadone is tightly-regulated, with safeguards to prevent diversion of supplies to the illicit market.  For this reason, heroin addicts under treatment are commonly prescribed oral linctus to be taken under supervision by the dispensing chemist or clinic.  Only once users have complied with a treatment programme for some time would they normally be allowed more than one days supply at a time. 

2.2       IDMU surveys

2.2.1    Methadone was included in the list of named drugs in the IDMU survey for the first time in 1999 [27] , and has continued in successive years.  A total of 325 respondents (4.0%) had ever used the drug, (based on age of first use responses rather than frequency data) of those 32 used daily - a relatively high proportion, and similar to the incidence of daily heroin use.   Only 25x users reported monthly spending, of whom 8 reported "free" (suggesting prescription) and 3 reported spending over £50, the highest at £90 per month, probably reflecting consultation fees for private prescriptions -the majority of daily users receive prescriptions.

Table 5 - UK use of heroin & methadone IDMU 1999-2002 Surveys
Frequency of use	Heroin	Methadone
Experimental	350	174
Occasional	73	40
Regular	39	9
Daily	50	32
Ex-Users	144	70
Would Never Use	2014	2221
Might Use	71	58
Never heard of	121	169
Blank response	5168	5257
Total Responses	2862	2773
Total Ever Used	656	325
Percent Ever Used	8.2%	4.0%
User-Rating (0-10)	1.82	1.46

2.2.2    The average user-rating of Methadone, 1.46 out of 10, is one of the lowest for any drug.  A handful of people gave it a positive rating (fig 4).   Only 2% of non-users (but users of other drugs, who expressed a preference) would try the drug if offered, one of the lowest ratios for any drug.  It is unlikely that methadone would be sold to, or tried by, any drug users other than heroin addicts or recovering addicts in treatment seeking to self-medicate.  As such, the abuse potential of methadone is low.

Fig 4 - Subjective ratings for Methadone

2.3       Prescription

2.3.1    Prescribed dosages range from virtually nil up to around 100mg per day, more in special cases, depending on the severity of addiction and stage of treatment (i.e. in a reducing maintenance regime smaller doses are prescribed over time).  If too much is prescribed, methadone may be sold on to other users, sometimes with tragic consequences for na"ve users with no tolerance level who may overdose.

2.3.2    The general prescribing practice is to allow the addict the minimum quantity required to stabilise his/her condition - the tendency is to under prescribe.  If too little is prescribed, addicts will usually supplement their prescription with street heroin.

2.4       Street Prices

2.4.1    I am unaware of any published figures within NCIS or related price lists in respect of methadone.

2.4.2    IDMU Prices - Since 1999, methadone prices have been sought by "dose" and "bottle".  Dose prices vary considerably, as there was no standard size unit (linctus being the most common form), with an average of £4.76 (free, £5 or £10 per "dose"-unspecified but approx 30ml, with methadone bottles (100ml) either "free" (prescribed) or most commonly £10 (average £9.84).

Table 6 - Methadone Street Prices 99-02
Drug	Dose		Bottle
	n	avg	n	avg
Methadone	47	£4.76*	16	£9.84*
* Reports of £50 and £70 (dose) and £70/£100 (bottle) discounted - included private consultation fees

Fig 5 - UK Methadone Price distributions 1999-2002

 

2.4.3    Methadone may be prescribed (either via drugs clinics or privately) to drug users to avoid or ameliorate the symptoms of withdrawal.  Prescribed drugs may be "stockpiled" to guard against periods of interrupted heroin supply, or during DIY attempts at withdrawal. 

3       Other Opiates

3.1       Introduction

3.1.1    A range of opiate preparations are available in medical practice, ranging from over the counter painkillers, through prescription only medicines, to powerful preparations only available to treat hospital in-patients.  The most common form of pharmaceutical opiates are tablets, although the drugs can also be in oral linctus, or injectable ampoules.

3.1.2    Many heroin addicts will obtain prescribed opiate drugs for periods during which they are unable to obtain heroin, as use of alternative opiates can delay or ameliorate withdrawal symptoms. 

3.1.3    The dosages used by opiate-dependent individuals may be several times the maximum recommended daily therapeutic dose.

Table 7 - Common Opiates - Comparison Chart [28]
Drug	Trade/Street name	Equivalent dose	Duration	Abuse Potential
Opium	Omnopon	10-20mg	4-5 hrs	Moderate-High
Morphine	Generic	10mg	4-5 hrs	High
Codeine	Generic	120mg	4-5 hrs	Low
Diamorphine	Heroin	3mg	3-4 hrs	High
Buprenorphine	Temgesic	0.2-0.6mg	6-8 hrs	Low
Dihydrocodeine	DF118	30mg	4-5 hrs	Moderate
Dipipanone	Diconal	10mg	4-5 hrs	High
Dextromoramide	<