Discussion on relative drug harm

Question 1

How can you investigate relative drug harm

Answer 1

1. PREVALENCE OF DRUG USE (UK)
2. RANGE OF PHYSICAL HARM
3. RANGE OF PSYCHOLOGICAL HARM
4. RANGE OF SOCIAL HARM

Question 2

Prevalence of use

Answer 2

 Measured the extent and trends of drug use in a nationally representative sample of 16-59-year olds in England and Wales (18/19)

• Includes the extent and trends in drug use among adults, including separate analysis of young adults (between 16 and 24 years)
• Highlights the frequency of drug use in the last year
• Highlights drug use by personal, household and area characteristics and lifestyle factors
• Highlights the use of new psychoactive substances (NPS)
• Discusses the perceived ease of obtaining illegal drugs
• Found that 1/11, 16-59-year olds and 1/5, 16-24-year olds have reported using an illicit drug in the last year
• Also observed that the majority of ecstasy and powdered cocaine users only take the drug once/twice a year, whilst 34% of cannabis users are classed as frequent users

 If we look specifically at the proportion of 16-59-year olds reporting use of selected drugs in the last years:
- Cannabis use higher among men (10.3%) than women (5%)
- Cocaine use higher among men (4%) than women (1.7%)
- Ecstasy use higher among men (2.1%) than women (1%)

Question 3

RANGE OF PHYSICAL HARM

Answer 3

 Drug-specific mortality
- Intrinsic lethality of the drug expressed as ratio of lethal dose and standard dose for adults
 Drug-related mortality
- The extent to which life is shortened by the use of the drug e.g. road traffic accidents, lung cancers, HIV, suicide
 Drug-specific damage
- Cirrhosis, seizures, strokes, cardiomyopathy, stomach ulcers
 Drug-related damage
- Includes consequences such as sexual unwanted activities and self-harm, blood-borne viruses, emphysema and damage from cutting agents
 Injury
- Extent to which the use of a drug increases the chance of injuries to others both directly and indirectly
- For example, violence, traffic accident, foetal harm, drug waste, secondary transmission of blood borne viruses

Question 4

RANGE OF PSYCHOLOGICAL HARM

Answer 4

 Dependence: the extent to which a drug creates a propensity or urge to continue to use despite adverse consequences
 Drug specific impairment of mental functioning = amphetamine induced psychosis, ketamine intoxication
 Drug-related impairment of mental functioning = mood disorders secondary to drug user’s lifestyle

Question 5

RANGE OF SOCIAL HARM

Answer 5

 Crime
- The extent to which the use of a drug involves/leads to an increase in volume of acquisitive crime, beyond the use of drug act
- At the population level this can be considered both directly and indirectly
 Environmental damage
- Extent to which the use and production of a drug causes environmental damage locally = discarded needles, toxic waste from amphetamine factories
 Family adversities
- Extent to which the use of a drug causes family adversities = family breakdown, economic wellbeing, emotional wellbeing, child neglect
 International damage
- Extent to which the use of a drug in the UK contributes to damage internationally = deforestation, international crime, new markets, destabilisation of countries
 Economic cost
- Extent to which the use of a drug causes direct costs to the country (health care, police, prisons) and indirect costs (loss of productivity)
 Community
- Extent to which the use of a drug creates decline in social cohesion and reputation of the community
 Loss of tangibles
- Extent of loss of tangible things = income, housing, jobs, educational achievements, criminal record, imprisonment
 Loss of relationships
- Extent of loss of relationship with family and friends

 All of the harms discussed can be divided into harm to self and harm to others

Question 6

How is expert ranking used to assess drug harm

Answer 6

 Analysis undertaken in 2010 by David Nutt (former government drug advisor) via a two-stage process:
- The UK Advisory Council on the Misuse of Drugs (ACMD) met in 2009 to determine drug harm criteria
- The Independent Scientific Committee on Drugs (ISCD) (a new organisation of drug experts independent of government interference) was convened in 2010 to develop a multicriteria decision analysis model
- MCDA model assessed scores for 20 representative drugs that are relevant to the UK and which spans the range of potential harms and extent of use
 Using the results:
- A total of sixteen harm criteria were identified, with nine criteria related to the harms that a drug produces in the individual and seven to the harms to others (both in the UK and overseas)
- Harms were clustered into five subgroups representing physical, psychological and social harms
 Total harm score for all the drugs and the part score contributions to the total from the sub-groups of harms to users and harms to others:
- Most harmful drugs to users were heroin (34), crack cocaine (37) and methamphetamine (32)
- Whereas the most harmful to others were alcohol (46), crack cocaine (17) and heroin (21)
- When two-part scores were combined, alcohol was the most harmful drug followed by heroin and crack cocaine
- Most harmful drug to others was alcohol by a wide margin
- Most harmful drug to users was crack cocaine followed closely by heroin
- Methamphetamine was the next most harmful to users, but it was of little comparative harm to alcohol, crack cocaine and heroin
- Alcohol with an overall score of 72 was judged to be most harmful, followed by heroin at 55 then crack cocaine with a score of 54
- Only eight drugs scored, overall, 20 points or more
 Drug-specific mortality was a substantial contributor to five of the drugs (alcohol, heroin, GHB, methadone and butane), whereas economic cost contributed heavily to alcohol, heroin, tobacco and cannabis
 These rankings led to David Nutt losing his position as the government’s drug advisor

Question 7

 Major criticism raised from using the expert ranking approach:

Answer 7

• The ranking depends too heavily on subjective personal criteria and not using purely scientific facts
• The methodology was criticised as it wasn’t normalised to the total number of users or the frequency of drug use = results could be biased/under-represent the harms of specific drugs

Question 7

 Major criticism raised from using the expert ranking approach:

Answer 7

-The ranking depends too heavily on subjective personal criteria and not using purely scientific facts
- The methodology was criticised as it wasn’t normalised to the total number of users or the frequency of drug use = results could be biased/under-represent the harms of specific drugs

Question 7

APPROACHES USED TO ASSESS DRUG HARM:
TOXICOLOGY BASED INDICES

Answer 7

 There are a number of toxicology-based indices that can be used to assess relative drug harm:
- Therapeutic index = the ratio of the median lethal dose (LD50) to the median effective dose (ED50) = this qualitative score provides a safety ratio
- UNODC Illicit Drug Index = a combination of a dose index (ratio between the typical dose and lethal dose) and a toxicology index (conc. levels in the blood of people who died from overdose compared with the conc. levels in persons who had been given the drug for therapeutic use)
- Ratio of number of deaths associated with a substance to its availability = availability can be determined by three separate measures: number of users as determined by household surveys, number of seizures by law enforcement agencies and estimates of the market size

Question 7

APPROACHES USED TO ASSESS DRUG HARM: 3. MARGIN OF EXPOSURE (MOE)

Answer 7

 Margin of exposure is a novel approach to compare the health risks of different compounds and to prioritise risk management actions
 MOE is defined as the ratio between the toxicological threshold (benchmark dose) and the estimated human intake
 Median lethal dose values from animal experiments were used to derive the benchmark dose
 Analysis by Lachenmeier and Rehm (2015) showed daily drug use of a number of substances, estimated using probabilistic analysis:
- The lower the MOE, the larger the risk for humans
- Alcohol had the lowest MOE, followed by heroin and cocaine
- The rankings seen in this paper were broadly consistent with the previous expert rankings

Question 8

APPROACHES USED TO ASSESS DRUG HARM: UK DRUG LEGISLATION

Answer 8

 A number of psychoactive substances are part of a regulated drug market (alcohol, tobacco) through a variety of means including taxation, sales and age of purchase
 However, a number of drugs are subject to control under the Misuse of Drugs Act 1971
- Was a means for controlling drugs (Class A-C)
- Grade penalties for drug possession and trafficking
- Temporary Controlled Drug Orders
- Advisory Council on Misuse of Drugs
 There isn’t always a correlation between the harm of the substance and its classification (e.g. alcohol scored as most harmful but is not found in class A-C)
 This could be the case because there are a number of external influences involved in the drug legislation process, not always just based on scientific evidence
- Pressure from the public
- Media attention
- Political input
- Lobby/pressure groups = reaction to high profile case

Question 9

ANALYSIS OF DRUG LEGISLATION (is it working)

Answer 9

 Before the Psychoactive Substances Act (2016) was introduced, chemists would get around the Misuse of Drugs Act in 1971 by synthesising a new drug with a slightly different chemical structure to make it unscheduled and therefore legal
 This drug could then be sold legally until the government managed to get it into the controlled drugs category = then it becomes illegal
 A new drug would then be synthesised, and the cycle continues
 The Psychoactive Substances Act (2016) was mainly focused on demonstrating psychoactivity but doesn’t really focus on drug harm
 There is limited data on the prevalence and harms of use in novel psychoactive substances
- In 2018-19, novel psychoactive substance use was highest between the 16-24 age category
- When looking at just the users of novel psychoactive substances = 26.6% were frequent users
 Still remains to be seen whether the Psychoactive Substances Act (2016) really caused a decline in use or whether participants were just less likely to admit use as it had now become illegal
 In terms of gathering scientific evidence on drug harm, it is an extremely challenging task as there is a constantly increasing number of novel psychoactive substances and only limited scientific evidence on relative drug harm
 What is needed:
- A range of in vitro studies using cell lines
- Animal model studies = in vivo
- Human studies to measure acute and chronic effects