Amphetamine use and purity
Amphetamine
Consumption Patterns
Amphetamine
is a Class B drug which nonetheless shows some features
of physical dependence. The main effects are an increase
in alertness and tolerance of physical activity Tolerance
to the stimulant effects develops rapidly - the main reason
why widespread prescribing of the drug for obesity was
restricted. A therapeutic dose of 5mg (pure) amphetamine
may have the same effect in a novice user as 300mg in
a heavily dependent user.
Alverno
et al[i] noted in 1975: 'Physical dependence is
rarely associated with amphetamine use. However pronounced
tolerance develops and the experienced amphetamine abuser
may eventually take more than 1g (pure drug) per day.'
In
our own IDMU surveys in 1994[ii] and 1984[iii] the heaviest amphetamine users reported
spending £300 to £500 per month on the drug in 1994, over
£100 per month in 1984 (when average purity was closer
to 20% and at a similar price (not allowing for inflation)[iv].
These surveys would under-represent heavier amphetamine
users due to the relatively small numbers involved, and
most of those who responded to the amphetamine questions
in both surveys were occasional or experimental users
of the drug. From the IMDU 1997-99 surveys, usage was
calculated on the basis of the number of monthly purchases,
the quantity purchased, and the percentage claimed for
personal use. A total of 770 amphetamine users provided
the raw data for these questions (Table 1).
Table
1 Amphetamine Usage
(IDMU 1997-99)
|
Percentile
|
Monthly
(g)
|
Daily
(mg)
|
1%
|
0.03
|
1
|
5%
|
0.18
|
6
|
10%
|
0.375
|
13
|
25%
|
0.875
|
29
|
50%
|
1.0
|
33
|
75%
|
4.0
|
133
|
90%
|
12.5
|
417
|
95%
|
22.4
|
747
|
99%
|
112
|
3733
|
Our
2001-05 surveys (n=9929) respondents were asked how much
street and base amphetamine they used per week (Table
2), of which 294 provided data for either or both purities.
Though the sample was smaller in relation to total respondents,
the distribution within the amphetamine users was similar.
Table
2 - Amphetamine Usage (IDMU 2001-2005)
|
Percentile
|
Street/wk (g)
|
Base/wk (g)
|
Total/wk (g)
|
Daily (g)
|
Pure drug
|
Mean
|
2.76g
|
1.93g
|
4.73g
|
0.68g
|
122mg
|
50%
|
1g
|
1g
|
2g
|
0.29g
|
57mg
|
75%
|
3g
|
3g
|
4g
|
0.57g
|
171mg
|
90%
|
8g
|
5g
|
10g
|
1.43g
|
329mg
|
95%
|
14g
|
14g
|
17.5g
|
2.50g
|
800mg
|
99%
|
48g
|
20g
|
56g
|
8.00g
|
1543mg
|
Max
|
70g
|
28g
|
70g
|
10.00g
|
2200mg
|
n
|
258
|
149
|
294
|
294
|
294
|
Continuous
daily use is rare, more frequently the drug is taken in
extended runs lasting up to several days, where sleep
is avoided by frequent use of relatively large amounts,
followed by a crash" where the user sleeps, in some cases
for several days, to wake up ravenously hungry and frequently
suffering acute depression[v]. This induces another bout of drugtaking
thus perpetuating the cycle. During the latter stages
of a binge the user may develop paranoid delusions and
may present as a psychiatric emergency. This amphetamine
psychosis" may be distinguished from schizophrenia in
that the symptoms recede in the absence of the drug.
Klee
& Morris[vi] found that 17% of iv. amphetamine users
surveyed reported spending more than £150 per week on
the drug. This would be equivalent to 10-30 grams (by
the gram) or 1.5 to 2 ounces (42-56g) if bought by the
ounce. 2% of injectors spend over £300 per week, most
probably 3 to 4 ounces (84 to 112g), representing 12-16
grams per day of street" quality material. Klee &
Reid[vii]
in a targeted study of 60 amphetamine users in the Greater
Manchester area found 42% of respondents consuming more
than the mean ~2g per ¬averageÿ day, with 16% consuming
over 4g and 2% over 5g per day. One in seven were daily
users, most used weekly or more often, 40% had injected
and 77% had ¬bingedÿ within the previous six months. Quality
was considered ¬veryÿ or ¬fairlyÿ important by 98% of
respondents, users would judge the quality by taste, smell
and appearance, and by trying it.
Caplin
& Woodward[viii] found that 11% of primary amphetamine
users spent more than £200 per week on the drug, with
3% spending over £250. These figures are consistent with
those of Klee & Morris above.
Oral
or intranasal use is less efficient than intravenous use,
but there is no recent published evidence as to the extremes
of consumption via these routes of administration. Newcombe[ix] suggested that ravers" might use half
a gram during a night of 6% speed (30mg), about 6 times
the therapeutic dose, but well below the dosages reported
elsewhere for primary amphetamine users.
Several
studies of individuals with amphetamine psychosis have
indicated daily dose ranges of the pure drug.
Connell[x] - 500mg to 975mg
Kramer[xi] - 150mg to 2000mg
Abruzzi[xii] - 2000-4000mg
Davis
& Schlemmer[xiii] - 100mg to 300mg
Reported
dosages from the literature must be qualified by the purity
of the amphetamine which was being consumed. Reports from
Sweden[xiv],
the USA[xv]
and Australia[xvi]
are not directly comparable as the markets in these countries
are different, and the purities and prices vary markedly.
Daily intravenous use of up to 1500mg (1.5g) of pharmaceutical
amphetamine was reported in the 1960s[xvii], equivalent to 30 grams of 5% powder.
Clearly, use of such quantities of low-quality powder
would be unrealistic, and intravenous use of such material[xviii][xix] would entail severe health risks from
the contaminants, although oral consumption of up to 8
grams per day is reported by ISDD[xx].
Heavier amphetamine users are thus more likely to seek
higher purity amphetamine powder, commonly (but inaccurately)
known as 'base'.
Given
the low purity of most street powders, larger quantities
of street amphetamine powder are required to produce the
desired effect. A typical 'recreational' dose of 50mg
pure drug would require 1g of 5% powder, or 5 grams of
1% powder. A heavily tolerant and dependent user seeking
to consume 600mg of pure amphetamine per day a person
would need to use 12 grams of 5% amphetamine powder, 6
grams of 10%, or 3 grams of 20% powder.
Purities
of Amphetamine Samples
A
study[xxi]
of drug content of powders examined in detail the purity
of amphetamine seizures made by Police and by Customs
& Excise between January and August 1992. The purity
of seizures were plotted against the amount seized. Average
purity of amphetamines seized by police was 5.1%, with
Customs seizures averaging 43.7%. In neither sample was
a relationship found between the amount seized and the
purity. There were seizures of 10kg with 3% and 4%, and
a seizure of a few grams with 16% amphetamine.
Home
Office statistics[xxii] chart the changes in amphetamine purity
over the past 10 years (fig 1). During the early 1990s
the average purity was typically 5-6%, which rose steadily
to 15-18% during 1998-99. Following successful police
action against a large manufacturing syndicate the availability
and purity of amphetamine fell back to 5-8% from late
1999 to mid 2001, although by late 2001 the average had
risen above 10% once more. This ¬amphetamine droughtÿ
coincided with a substantial increase in usage of cocaine
and crack.
Fig
1
Illicit
amphetamine tablets were found[xxiii] to contain 30-40mg amphetamine, compared
to proprietary ¬dexedrineÿ (d-amphetamine) tablets of
5mg. However illicit tablets would contain a racemic mixture
of both d-amphetamine and the inactive l-amphetamine stereoisomers,
thus the active drug content of illicit tablet preparations
would be 3-4 times that of proprietary tablets. With a
typical tablet weight of around 300mg, this would represent
typical tablet ¬puritiesÿ of 10-13%.
The
range of amphetamine purities analysed by the Forensic
Science Service during 1997 were given in a Home Office
written answer in April 1998 and are reproduced in table
3 below.
Table
3 - Amphetamine Purities 1997[xxiv]
|
Purity
|
Percentage of cases
|
Less than 5%
|
36
|
5-10%
|
24
|
10-20%
|
17
|
20-30%
|
10
|
30-40%
|
6
|
40-50%
|
3
|
50-60%
|
2
|
60-70%
|
2
|
More than 70%
|
1
|
Police mean 14%
|
Police mode 5%
|
Customs mean
|
approx
40% purity
|
A
report of purities of amphetamine samples analysed by
the Wetherby laboratory[xxv]
(covering Yorkshire, Humberside & North East England
found amphetamine purities of samples analysed during
the period January-June 1995 averaged 7.8%, and from July
to December 1995 the report indicates an average purity
of 10%, with most street samples in the range 1%-9%, with
the most common cutting agents being glucose, with caffeine
and ephedrine often present. The average wrap size was
646mg (no range given).
It
is apparent from these figures that the common assumption
that amphetamine would be cut to levels of 5% or less
are outdated, representing less than median purity, and
that a substantial proportion of amphetamine on the UK
market is sold at higher purities - 41% of seizures were
found to be over 10% purity in 1997.
Wrap
sizes
The
average wrap size analysed by the Wetherby laboratory[xxvi]
was 616mg in January-June and 646mg in July-December 1995
(no range given). Analysed wraps will tend to underestimate
the sizes of wraps sold on the street, as partially used
wraps may be seized and analysed, and these will tend
to depress the average. The analysed average of seized
wraps would thus fall somewhere between 50% and 100% of
the actual average wrap size when sold. Analysed wrap
sizes would therefore be consistent with an actual wrap
size (when sold) of approximately one gram.
Preliminary
results from the 1995-97 series surveys[xxvii]
indicate purchase quantities of amphetamine to range from
one gram wraps to over 100g, with 1/8oz (3.5g) at £15-£25
being the average purchase among regular amphetamine users.
©
IDMU Ltd 2006
[i]
Alverno L, Larson C & Hieb E (1975) Recognising
Amphetamine Psychosis. Drug Therapy 5(11) pp92-96
[ii]
Atha MJ & Blanchard S. (1997) op cit.
[iii]
Atha M.J. [1984] op cit.
[iv]
Baker O & Marsden J (Eds) ISDD Audit of Drug Misuse
in Britain 1994.
[v]
Hoffman FG [1983] Handbook on Drug and Alcohol Abuse (2nd
Ed) New York: Oxford University Press.
[vi]
Klee H. & Morris J [1994] Crime & Drug Misuse:
Economic and Psychological aspects of the criminal activities
of heroin and amphetamine injectors. Addiction Research
1(4) 377-386
[vii]
Klee H & Reid P (1995) Amphetamine-Misusing Groups
: A feasibility study of the use of peer group leaders
for drug prevention work among their associates London:
Home Office
[viii]
Caplin S & Woodward S [1986] Drugwatch - Just say
No. London: Corgi p48
[ix]
Newcombe RD [1991]. Raving and Dance Drugs. Manchester:
Lifeline Project/3-D Research
[x]
Connell PH (1958) Amphetamine Psychosis Institute of Psychiatry
Maudsley Monographs No 5. London: Oxford University Press
[xi]
Kramer JC (1970) Current Concepts on Amphetamine Abuse,
Rockville MD: NIMH
[xii]
Abruzzi W (1977) Drug Induced Psychosis International
Journal of the Addictions 12(1) pp183-193
[xiii]
Davis JM & Schlemmer RF (1980) The Amphetamine Psychosis.
Ch in Caldwell J (Ed) Amphetamines and Related Stimulants.
Boca Raton: CRC Press.
[xiv]
Gardner R,. [1968] Psychotomimetic effects of central
stimulants. Paper in Sjoqvist F & Tottie M (Eds) Abuse
of Central Stimulants. (Symposium arranged by the
Swedish Committee on International Health Relations. 25-27/11/68)
Stockholm: Almqvist & Wiksell. - Also, discussions
by Bergsman A, Cohen S during symposium.
[xv]
Morgan JP & Kagan D. [1978] Street amphetamine quality
and the Controlled Substances Act 1970. Ch. in Smith DE
et alia (Eds) Amphetamine Use, Misuse, and Abuse. Proceedings
of the National Amphetamine Conference 1978. Boston Ma:
G.K.Hall & co.
[xvi]
Moore D. Saunders B & Hawks D. [1993] Recreational
Drug Use, with particular reference to Amphetamines, Ecstasy
and LSD, amongst a social network of young people in Perth,
Western Australia. Curtin University of Technology. Bentley,
Western Australia. - Amphetamine 50-90% pure at bulk level,
15% at street level.
[xvii]
Gardner R,. [1968] op cit.
[xviii]
Atha M.J. [1987] op cit. - More respondents had injected
amphetamines (speed) than opiates.
[xix]
Klee H. [1992] A new target for behavioural research -
amphetamine misuse British Journal of Addiction 87 439-446.
- Amphetamine injectors commonly reported by drugs agencies.
[xx]
Baker O & Marsden J (Eds) ISDD Audit of Drug Misuse
in Britain 1994
[xxi]
King LA, Clarke K & Orpet AJ [1993] The Drug Content
of Powders and Other Illicit Preparations. Drugs Intelligence
Laboratory, Forensic Science Service, Aldermaston. Technical
Note No. 780
[xxii]
Home Office Statistical Bulletin (1996) issue 25/96. Statistics
of drugs seizures and offenders dealt with, United Kingdom
1995. London HMSO
[xxiii]
King LA, Clarke K & Orpet AJ [1993] The Drug Content
of Powders and Other Illicit Preparations. Drugs Intelligence
Laboratory, Forensic Science Service, Aldermaston. Technical
Note No. 780
[xxiv]
Hansard 1-4-98 - Commons Written Answers col 538 (George
Howarth - Home Office)
[xxv]
Humberside Police [1996] - Humberside Drug Prices January
1996. Disclosed in proceedings at Grimsby Crown Court
25-1-96
[xxvi]
Humberside Police [1996] - Humberside Drug Prices January
1996. Disclosed in proceedings at Grimsby Crown Court
25-1-96
[xxvii]
Atha MJ, Blanchard S & Davis S (1998?) Regular Users
II - in preparation preliminary data from first 200 questionnaires
analysed