Substance misuse psychiatry Flashcards
Explain why alcoholic seizures can occur when dependent drinkers suddenly stop drinking.
Alcohol is a CNS depressant that works by stimulating the inhibitory GABA system. When dependent drinkers stop drinking the neural pathways become hyperexcitable and seizures can occur. These are generalised tonic-clonic seizures.
In extreme cases of alcohol withdrawal patient’s can get delirium tremens. What is this?
Delirium tremens is a medical emergency. It is the presence of a hyperadrenergic state with severe agitated confusion that can appear 48-72 hours after alcohol has been stopped. It is characterised by confusion, delusions, hallucinations (usually visual - of people and animals), affective changes such as alternation between extreme fear and hilarity, gross tremor, sweating, tachycardia, hypertension, dilated pupils and fever.
What blood results would raised suspicion of recent alcohol abuse/alcoholic liver disease?
Isolated or disproportionate elevation of gamma-GT compared to other liver enzymes (such as ALP or ALT).
What percentage of alcohol-dependent patients develop clinically relevant symptoms of withdrawal?
50%
What is the recommended pharmacological method of alcohol detoxification? Name specific drugs
- A reducing benzodiazepine regime is used. Usually, chlordiazepoxide (a long-acting benzo) - an alternative is diazepam.
- And thiamine - vitamin B1 - is prescribed as prophylaxis against Wernicke’s encephalopathy. Usually in the form of IV Pabrinex.
Which blood investigations would you carry out in a patient with suspected alcoholism. Describe the expected results.
FBCs and LFTs.
- FBCs: You would expect a macrocytic anaemia, i.e. raised MCV due to B12 deficiency.
- LFTs: Raised gamma-GT with recent heavy alcohol use and raised transaminases suggestive of hepatocellular damage.
Name an anti-craving drug used to prevent relapse in alcholics
Acamprosate. (This can be given to help intense anxiety, insomnia and craving, but is contraindicated in pregnancy and severe liver failure).
Which drug is used to treat chronic alcohol dependence by causing extremely unpleasant side effects such as flushing, throbbing headache and palpitations when alcohol is ingested? And how do these effects occur?
Disulfiram (antabuse) is used and it causes these effects due to acetaldehyde build up.
What causes Wernicke’s Encephalopathy and how does it present?
Wernicke’s Encephalopathy is caused by acute thiamine deficiency. It presents with a classic triad of: confusion, ataxia (wide-based gait) and ophthalmoplegia.
How is Wernicke’s encephalopathy treated and what does it lead to if left untreated?
It’s treated with urgent IV thiamine (Pabrinex). If there is coexistent hypoglycaemia, thiamine must be given BEFORE glucose. If left untreated, Wernicke’s encephalopathy can lead to irreversible Korsakoff’s syndrome.
Name three symptoms of Korsakoffs
Anterograde amnesia, some retrograde amnesia and confabulation.
Name four ‘local’ complications of IV drug use and three systemic complications.
Local: 1) Abscess formation 2) Cellulitis 3) DVT (repeated injection into femoral veins damages valves and slows venous return) 4) Emboli
Systemic: 1) Septicaemia 2) Infective endocarditis 3) Blood borne infections such as HIV and Hepatitis B&C
Opiate intoxication can be identified by what sign in the eyes?
Pin point pupils
Withdrawal from IV heroin use can be remembered as “everything runs”. What are the symptoms?
Diarrhoea, vomiting, lacrimation and rhinorrhoea. Dysphoria & agitation also occur. (Remember withdrawal is extremely unpleasant but rarely life threatening).
What drugs are used in substitute prescribing for heroin addicts?
Methadone (liquid) and buprenorphine (sublingual tablet).
In opiate withdrawal, what drugs can be used to prevent:
a) diarrhoea and…
b) nausea/vomiting
a) Loperamide
b) Metoclopramide
Name an opiate antagonist that can be given as prevention against relapse in those who have completed opiate detoxification
Naltrexone
What is the antidote for opiate overdose?
Naloxone
Side effects of cannabis use include blood-shot eyes, tachycardia and dry mouth. What is the medical term for blood-shot eyes?
Injected conjunctivae
Name two recognised features of chronic, heavy cannabis use
Lethargy and poor motivation
cocaine users may experience formication. What is this?
The sensation that insects are crawling on or below the skin (cocaine bugs)
Why does septal perforation occur in chronic cocaine use?
Cocaine is a powerful vasoconstrictor and snorting it damages the nasal mucosa, causing necrosis and septal perforation.
What are people referring to when they talk about the drug “speed”?
amphetamine
How does ecstasy (MDMA) cause a high? What class of drug is it?
It causes release and reuptake inhibition of serotonin. It is a cross between a stimulant and hallucinogen (but hallucinations are rare).
What form does LSD (acid) usually come in? What occurs when LSD is ingested? Which neurotransmitter systems are affected?
LSD is a hallucinogen and it is usually impregnated on tabs (tiny squares of paper with pictures on them). Ingestion affects the dopamine and serotonergic systems, causing trips of up to 12 hours duration, with perceptual changes and euphoria.
What type of drug is ketamine? What effect does it have?
Ketamine is a hallucinogen and a dissociative anaesthetic that prevents the brain’s awareness of pain.
(People can severely harm themselves whilst hallucinating due to the anaesthesia e.g. pulling out their own teeth).
What causes the sedative effect of benzodiazepines?
Benzodiazepines enhance the inhibitory effect of GABA transmission (similar effect to alcohol)
What drug is used to treat benzodiazepine OD?
Flumazenil (a benzodiazepine antagonist).
What causes the sedative effect of benzodiazepines?
Benzodiazepines enhance the inhibitory effect of GABA transmission (similar effect to alcohol)
What drug is used to treat benzodiazepine OD?
Flumazenil (a benzodiazepine antagonist).
