substance misuse 1

Question 1

what is substance abuse?

Answer 1

“A disorder characterised by the destructive pattern of using a substance which leads to problems or distress”

Question 2

why does people abuse?

Answer 2

As a normal physiological function, engaging in (positive) rewarding behaviours lead to pleasurable feelings

Question 3

what is addiction

Answer 3

Addiction: a state characterized by compulsive engagement in rewarding stimuli despite adverse consequences

Question 4

what is reinforcing stimuli

Answer 4

Reinforcing stimuli: stimuli that increase the probability of repeating behaviours paired with them

Question 5

what is rewarding stimuli

Answer 5

Rewarding stimuli: stimuli that the brain interprets as intrinsically positive or as something to be approached

Question 6

what is addictive drug

Answer 6

Addictive drug: a drug that is both rewarding and reinforcing

Question 7

what is addictive behaviour

Answer 7

Addictive behaviour: a behaviour that is both rewarding and reinforcing

Question 8

what is sensitisation

Answer 8

Sensitisation: an amplified response to a stimulus resulting from repeated exposure to it

Question 9

what is tolerance

Answer 9

Tolerance: the diminishing effect of a drug resulting from repeated administration at a given dose

Question 10

what is dependence

Answer 10

Dependence: an adaptive state associated with a withdrawal syndrome upon cessation of repeated exposure to a stimulus (e.g., drug intake)

Question 11

what is physical dependence

Answer 11

Physical dependence: dependence that involves persistent physical–somatic withdrawal symptoms (e.g., fatigue and delirium tremens)

Question 12

what is psychological dependence

Answer 12

Psychological dependence: dependence that involves emotional–motivational withdrawal symptoms (e.g., dysphoria and anhedonia)

Question 13

Factors affecting likelihood of abuse

Answer 13

Abuse:
Sexual, psychological, emotional or physical abuse can influence drug use as a coping mechanism

Underlying emotional disorders:
Individuals with anxiety, depression, bipolar disorder or post-traumatic stress disorder are at increased risk of substance abuse and addictive behaviours.

Family history:
Children raised by alcoholic or drug-addicted parents are more likely to develop substance use problems.

Inherited factors:
Genetic susceptibilities and biological traits play a role in addiction and abuse but development is shaped by a person’s environment

Low frustration tolerance:
Addicts are highly susceptible to the negative effects of stress,

The substance:
Some substances are more addictive than others.

Question 14

Functional effects of abused substances

Answer 14

stimulants -
hallucingogen
depressents
anti-psychotics

Question 15

Biological systems involved in effects

Answer 15

Physiological:
Acetylcholine: piracetam
Adenosine: caffeine
Dopamine: cocaine, phenidates, amphetamines
GABA: benzodiazepines
Norepinephrine: yohimbine
AMPAR: piracetam
CB1R: tetrahydrocannabinol (in cannabis), cannabinomimetic NPS
NMDAR: ketamine
Opioid receptors: buprenorphine, heroin
Orexin receptor: modafinil

Anatomical:
Meso-cortico-limbic system
Hypothalamus
See PM3B lecture on brain area functions

Question 16

Approaches to treatment
2 categories

Answer 16

NHS treatment approaches are evidence-based

Private practices also use non-evidence-based and disproven practices (e.g. homeopathy, acupuncture etc.)

Treatment approaches can be divided into two categories:
Pharmacotherapy
Behavioural therapies

Generally, treatment is most often effective when both are combined
Treatment also reduces long term health risks to patients (e.g. blood borne diseases) and reduces other harmful behaviours (e.g. acquisitive crime)
Every £1 spent on treatment saves £2.50 on crime and health costs

Question 17

what are Behavioural treatment approaches

Answer 17

Cognitive-behavioural therapy
Based on behaviours being learned responses which, through learning different responses, can be altered.

Contingency Management Interventions
Rewards compliance with abstinence

Motivational Enhancement Therapy
Focusses on identifying the need to change behaviours

Family Behaviour Therapy
Therapy undertaken with at least one significant other at session

Question 18

what are the Principles of pharmacological therapies for substance misuse

Answer 18

Abstinence:
included as can include use of pharmacological treatments which deter misuse e.g. Disulfiram for alcohol abuse, naltrexone after detoxification is complete)

Detoxification:
Pharmacological induction of withdrawal e.g. naltrexone to block opioid receptors plus lofexidine (a2A adrenoceptor agonist) to reduce withdrawal symptoms)

Replacement/substitution therapy:
Replacement of abused substance with, typically, a longer acting but less euphoric substitute (e.g. buprenorphine to replace heroin)
Encourages stability and routine

Formulation or distribution to reduce misuse potential of replacement therapies:
E.g. sublingual buprenorphine and naloxone has poor naloxone (antagonist) bioavailability but, if injected, blocks effects of buprenorphine (and other opiates)

Question 19

The role of the pharmacistin substance misuse

Answer 19

Provision of substance misuse services
Primarily pharmacological therapies
>200,000 people in treatment in a given year (~18 per UK pharmacy)
Reporting missed doses
Needle exchange schemes
Health promotion and harm reduction

Identifying interactions

Detecting misuse:
Unusual patterns of OTC medicine purchase (e.g. of codeine-containing medicines)
Altered prescriptions (quantity, strength)
Diversion of medicines