Substance use disorder: drugs Flashcards
What are the 4 categories of recreational drugs?
Analgesics e.g. heroin, morphine, fentanyl, codeine
Depressants e.g. alcohol, barbituates, tranquilizers, nicotine
Stimulants e.g. cocaine, methamphetamine, ecstasy (MDMA)
Hallucinogens e.g. LSD (acid), peyote (mescaline), magic mushrooms (psilocybin), salvia divinorum (diviner’s sage)
NB: Cannabinoids - has depressant, stimulant and hallucinogen effects.
Define harmful use in terms of substance problems.
A pattern of psychoactive substance use that is causing damage to health.
The damage may be physical (as in cases of hepatitis from the self-administration of injected drugs) or mental (e.g. episodes of depressive disorder secondary to heavy consumption of alcohol)
Define substance abuse or misuse.
The continued misuse of any psychoactive substance that severely affects person’s physical and mental health, social situation and responsibilities.
Define psychoactive substance.
Substance that has an effect on the central nervous system
What is the ICD-10 criteria for dependence?
- Compulsion - strong desire
- Control - difficulties in controlling substance-taking behaviour (onset, termination, levels)
- Withdrawal - when substance use has ceased
- Tolerance - increased doses required
- Salience - little alternative pleasure
- Persistance - use despite clear evidence of harm
3 or more of the following manifestations should have occurred together for at >1 month or, if persisting for periods of <1 month, should have occurred together repeatedly within a 12-month period.
Define ‘legal highs’.
a.k.a. novel psychoactive substances is the medical term for the many new substances which are chemically related to established recreational drugs such as MDMA and cannabis
Illegal since 2016, so no longer ‘legal’ highs
Give an example of each category of legal highs.
Stimulants - similar to NMDA, amphetamines and cocaine e.g. mephedrone called ‘bath salts’
Cannabinoids - ‘spice’ which is a synthetic cannabinoid receptor antagonist sprayed on herbal mixtures which are then smoked
Hallucinogenics
- Dissociatives - similar effect to ketamine e.g. methoxetamine ‘mexxy’.
- Psychedelics - similar effect to LSD but also sometimes stimulant
Depressant - either opioid or benzo based but often have a longer half-life
Other e.g. GHB ‘liquid ecstasy’, ‘Geebs’ or ‘G’; nitrous oxide ‘hippie crack’.
What is the MOA of stimulant legal highs?
Similar to MDMA, amphetamines and cocaine –> increased levels of serotonin, dopamine and noradrenaline –> in a ‘high’ and feeling of euphoria
What form is ‘spice’ often used in?
- Sprayed on herbal mixtures and smoked or
- Liquid inhaled using e-cigarettes
What is a dangerous side effect of GHB use?
Respiratory depression - when taken with other respiratory depressants, most commonly alcohol, this can be potentially life threatening
What is the MOA of benzodiazepines?
Enhance the effect of the inhibitory neurotransmitter GABA* by increasing the frequency of chloride channels.
*gamma-aminobutyric acid
NB: GABAA drugs
- benzodiazipines increase the frequency of chloride channels
- barbiturates increase the duration of chloride channel opening
- Barbidurates increase duration & Frendodiazepines increase frequency
What are the 5 effects/uses of benzodiazepines?
- sedation
- hypnotic
- anxiolytic
- anticonvulsant
- muscle relaxant
What are the short and long-term risks of using benzodiazepines?
Short-Term: drowsiness (do not drive), reduced concentration
Long-Term: cognitive impairment, worsening anxiety and depression, sleep disruption
What are the symptoms of benzodiazepine withdrawal?
Can occur up to 3 weeks after stopping a long-acting drug. Features include:
- insomnia
- irritability
- anxiety
- tremor
- loss of appetite
- tinnitus
- perspiration
- perceptual disturbances
- seizure
What is the protocol for withdrawing benzodiazepines?
Withdrawn in steps of about 1/8 (range 1/10 to 1/4) of the daily dose every 2 weeks. Suggested protocol:
- Switch patients to the equivalent dose of diazepam (up to 40mg OD)
-
Reduce dose of diazepam every 2-3 weeks in steps of 2 or 2.5 mg
- time needed for withdrawal can vary from 4 weeks to a year or more
What are the clinical features of benzodiazepine toxcity? What is the antidote?
- CNS depression
- Ataxia
- Slurred speech
- Coma
- Respiratory depression
Tx: flumazenil (GABA receptor antagonist) - majority of overdoses are managed with supportive care only due to the risk of seizures with flumazenil. It is generally only used with severe or iatrogenic overdoses.
What is the MOA of cocaine?
Stimulant – classified as such as they clinically resemble a state of increased sympathetic activity.
MOA: Blocks the uptake of dopamine, noradrenaline and serotonin.