Addictions Psychiatry

Question 1

Define tolerance

Answer 1

reduced responsiveness to a drug caused by previous administration

Question 2

what types of drugs can cause tolerance to develop?

Answer 2

opioids, ethanol, barbiturates, benzodiazepines

Question 3

What kind of tolerance means that less drug reaches the active site?

Answer 3

dispositional tolerance

Question 4

What mechanisms result in dispositional tolerance?

Answer 4

decreased rate of absorption
increased rate of metabolism to inactive metabolites
decreased rate of metabolism to active metabolites

Question 5

name two mechanisms for tolerance

Answer 5

dispositional

pharmacodynamic

Question 6

what type of tolerance means the drug has less action at the active site?

Answer 6

pharmacodynamic

Question 7

what mechanisms result in pharmacodynamic tolerance

Answer 7

down regulation or internalisation of drug receptors
reduced signalling down stream of drug receptors
some other compensatory mechanism

Question 8

acute and withdrawal effect of opioid

Answer 8

constipation acute

diarrhoea withdrawal

Question 9

acute and withdrawal effect of barbiturate

Answer 9

anticonvulsant acute

convulsions withdrawal

Question 10

acute and withdrawal effect of cocaine

Answer 10

elevated mood acute

depressed mood

Question 11

does tolerance = dependence? illustrate with a diagram

Answer 11

no

Question 12

What is the basis of psychological craving?

Answer 12

reward centre

Question 13

what is the basis of physical dependence?

Answer 13

tolerance

Question 14

Describe the reward pathway

Answer 14

reward pathway involves neurones that project from the ventral tegmental area to the nucleus accumbens and prefrontal cortex. When the VTA neurones are stimulated dopamine is released. This causes a sensation of pleasure/reward

Question 15

What is the reward pathway normally activated by?

Answer 15

eating, drinking, sex

Question 16

What is function of reward centre?

Answer 16

evolution - propagation of genes

Question 17

discuss the basis of psychological craving

Answer 17

The reward pathway involves neurones that project from the ventral tegmental area to the nucleus
accumbens and prefrontal cortex. When the VTA neurones are stimulated dopamine is released. This
causes a sensation of pleasure/reward. The reward pathway is normally activated by eating, drinking
and sex. It therefore encourages those “healthy” behaviours that lead to propagation of your genes.
It is a powerful thing. Some drugs of abuse tap into the reward pathway and increase dopamine levels.
Heroin increases firing rate of dopaminergic neurones. Amphetamine increases dopamine release.
Cocaine inhibits dopamine reuptake. Alcohol also interferes with the reward centre. This produces
psychological component of addiction – craving.

Question 18

discuss the effects of cocaine

Answer 18

Cocaine is the most potent natural stimulant that is extracted from leaves of coca plant. It was first
isolated in 1880s. It was formerly used in eye, nose and throat surgery. The coca leaves are chewed
or brewed. Cocaine hydrochloride is snorted or injected. Cocaine freebase or crack cocaine is smoked.
The effects of cocaine is dependent on the dose and rate of entry to the brain. With smoking it is
Figure 2 Transmitter Response
almost immediate. Injected takes 15-30s whilst snorting takes 3-5mins. The effects of crack smoking
are very intense but last only 15 mins. Cocaine is a stimulant and euphoriant – dopamine. It causes
increased alertness and energy. Additionally, it causes increased confidence and impaired judgement.
It lessens appetite and desire for sleep. However, it comes with many adverse effects including
damage to the nose and airways. It can cause convulsions with respiratory failure. Cardiac arrhythmias
and MI may result from cocaine use. Hypertension (potent vasoconstrictor), CVA, toxic confusion and
paranoid psychosis are other effects of cocaine use. Cocaine withdrawal causes: depression,
irritability, agitation, craving, hyperphagia and hypersomnia. Couple of lines cost around £50. Can
continue to take until run out of money. Relatively easy to stop as it doesn’t have a huge physiological
dependence.

Question 19

discuss amphetamines

Answer 19

Generally, it is in the form of amphetamine sulphate. Amphetamine can be sniffed, swallowed or
injected. The powder form costs around £10/g, “ice” about £25/g. The effects are similar to cocaine
but last longer. Toxic confusion occasionally comes with convulsions and death. Amphetamine
psychosis in heavy chronic use.

Question 20

give examples of opiates

Answer 20

opium
morphine
heroin (Diamorphine)
methadone
coeine
dihydrocodein

Question 21

discuss heroin

Answer 21

Heroin was first synthesised from morphine in 1874. The addictive potential was unrecognised for
many years. It is available as diamorphine or diamorphine hydrochloride. It may be presented as
powder or as an almost tar like substance. Purity varies from 1-98% with an average of 35% in the US.
Also known as H, gear, smack or brown. It can be taken by snorting, smoking (chasing the dragon) or
injection. Move to injection because tolerance and dependence have developed and its cheaper to
inject. Bag costs around £10-30. Smoking is the safest method of use, whilst injection the most
dangerous

Question 22

what does heroin cause?

Answer 22

• Analgesia
• Drowsiness and sleep
• Mood change – euphoria, intense pleasure
• Respiratory depression
• Cough reflex depression
• Sensitisation of the labyrinth with nausea and vomiting
• Decreased sympathetic outflow (bradycardia and hypotension)
• Lowering of body temperature
• Pupillary constriction
• Constipation
• Respiratory arrest with a pulse (almost pathognomic of opiate OD in adults)
• Pinpoint pupils unreactive to light
• Snoring giving way to shallow respiration (<8 breaths/min)
• Bradycardia and hypotension
• Varying degree of reduced consciousness/coma

Question 23

what are the effects of opiates (first, medium, longer)?

Answer 23

A very intense but transient feeling of pleasure. “A rush” that is almost orgasmic. Physical and
emotional anaesthetic. SEs of opiates:
• First time
o Nausea/vomiting, headache
• Medium term
o Phlebitis, anorexia, constipation
• Longer term
o Tolerance, withdrawal, social and health problems

Question 24

symptoms of opiate withdrawal syndrome

Answer 24

• Craving
• Insomnia
• Yawning
• Muscle pains and cramps
• Increased salivary, nasal and lacrimal secretions
• Dilated pupils
• Piloerection (hence “cold turkey”)

Question 25

methadone maintenance

Answer 25

In some effects this decriminalises drug use by allowing normalisation of the lifestyle. It does however reduce IV misuse. There has been leakage on to the illicit market. People generally take less heroin if they are on methadone. It reduced risk of death massively.

Question 26

discuss ecstasy

Answer 26

MDMA (3,4-methylenedioxymethamphetamine) is almost always used orally, costing £10-15 per tab. It causes a relaxed euphoric state without hallucinations. Half of all ecstasy tabs contain no MDMA instead they are either: no active ingredient, LSD, amphetamine or ketamine. The effects of MDMA are likened to a mixture of LSD and amphetamine. Euphoria is followed by a feeling of calm. Increased sociability is paired with an inability to distinguish between what is and isn’t desirable. The effects come on after 20 mins and last 2-4 hours. Side effects include nausea, dry mouth, increased blood pressure and temperature. In clubs users risk dehydration. Larger doses can cause anxiety and panic. Long term use can cause drug induced psychosis. There have been some suggestions that it may cause liver and brain cell damage. Taking lots can cause insomnia, anxiety and depression in the long term.

Question 27

discuss cannabis

Answer 27

Cannabis is the most commonly used illicit drug. Tetrahydrocannabinol is the psychoactive agent. It is presented as marijuana, hashish (cannabis resin), or as hash oil (produced by extracting cannabinoids from plant material with a solvent). Skunk (sensimilla) has a high THC content. Usually sold by the ounce at £12-15 per eighth/oz for resin to £25 per eighth for marijuana. Can be eaten but is usually smoked (joints spliffs or blunts). Production is becoming more professional in that the THC content is rising. The psychological effects can be varied with relaxing or stimulating. It causes euphoria, increased sociability and hilarity, increased appetite, changes in time perception and synaesthesia. In high doses it causes anxiety, panic, persecutory, ideation, and hallucinatory activity. Ill effects include respiratory problems (as with tobacco), toxic confusion, exacerbation of major mental illness, ? cannabis psychosis.

Question 28

discuss anabolic steroids

Answer 28

These are a family of drugs comprising testosterone and many synthetic analogues. These drugs are legitimately prescribed in hypogonadism, muscular dystrophy, various anaemias, and muscle wasting in AIDS. Its use in sports requiring muscle mass and strength has expanded rapidly. Also used to enhance appearance by increasing muscle mass and reduce body fat. Muscle hypertrophy from steroid use is particularly marked in the upper body in the pectoralis, deltoid, trapezius, and biceps

Question 29

side effects of anabolic steroids

Answer 29

• Skin o Rash, stretch marks, baldness • Feminisation in males with hypogonadism and gynaecomastia (occasioning use of antioestrogens) • Virilisation in women o Hirsutism, deep voice, clitoral enlargement, menstrual irregularities, hair thinning • Cardiovascular o Increased cholesterol and hypertension • Growth deficits due to premature closure of epiphyses • Liver disease – cholestatic jaundice, liver tumours • Psychological o Irritability and anger – roid rage o Hypomania and mania o Depression and suicidality on withdrawal