Pharmacological Management Of Addiction Flashcards
What is the management plan for acute behavioural disturbances?
De-escalation techniques and observation are preferred or physical restraint that is appropriate and proportionate to the situation for the shortest time possible to avoid self-injury or harm to others.
Benzodiazepines are the first line pharmacological treatment with the intramuscular use of lorazepam which is preferred for patients with an unknown psychiatric history or cardiac history.
Alternative medication is combination haloperidol with promethazine, a sedating anti-histamine medication. can be used
What are the risks with the use of benzodiazepines?
Respiratory arrest/depression
Loss of consciousness
Cardiovascular collapse
Disinhibiton’
What are the risks with the use of antipsychotics?
Loss of consciousness
Cardiovascular complications
Seizures
Akithisia
Dystonia
Neuroleptic malignant syndrome
What is the management plan for a patient with alcohol withdrawal?
Tapering regime of gradual reduction of alcohol use with the use of benzodiazepines, typically lorazepam or diazepam to reduce the risk of alcohol tremens.
Thiamine and folate supplementation to avoid neuropathy of Wernicke’s and Korsakoff’s.
Pharmacological use of naltrexone, chlordiazepoxide and/or disulfiram.
What is naltrexone?
Competitive antagonist of opioid receptors with the highest affinity to mu-opioid receptors which is indicated for opiate dependence and alcohol dependence. It must not be prescribed for patients currently on opiates and can cause abdominal pain, anxiety and abnormal appetite.
What is disulfiram?
Blocks the oxidation of acetaldehyde via the irreversible inactivation of alcohol dehyrdogenase during alcohol metabolism which leads to a build up and unpleasant symptoms of nausea, drowsiness, allergic dermatitis and fatigue. It is indicated for alcohol dependence.
How do addictive substances act on the brain?
Substances such as amphetamnines, cocaine, alcohol and cannibalism act on the ventral tegmental area to mediate dopamine release to act on the nucleus accumbens for reward and pleasure.
What are the side effects of alcohol withdrawal?
Increased pulse rate and blood pressure
Increased temperature
Shaking, vomiting and sweating
Sleep difficulties
Poor appetite and nausea
Diarrhoea and heartburn
Risk of non-epileptic seizures due to excess ethanol causing desensitisation to GABA
What is the criteria for admission for alcohol withdrawal?
Young person under 16
High risk of withdrawal seizures or delirium tremens
Vulnerable person e.g with co-morbidities or elderly
What is the action of clordiazepoxide?
Binds to benzodiazepine binding sites on the GABA receptor to enhance its inhibitory effects for sedation and anxiolytic properties, indicated for alcohol withdrawal and short term use in anxiety. It is contraindicated for respiratory weakness, phobic states and chronic psychosis.
In cases of liver failure, lorazepam is preferred due to the sedative effects of chlordiazepoxide.
What is Korsakoff’s syndrome?
Neuropsychiatric condition caused by a depletion of thiamine (Vitamin B1) where there is a memory disorder due to alcohol misuse.
What is Wernicke’s encephalopathy?
Degenerative brain disorder caused by a depletion of thiamine resulting in opthalmoplegia, ataxia and confusion/delirium.
What are the risk factors for Wernicke’s encephalopathy?
Coma
Hypoglycaemia
Memory blackouts
Significant weight loss
What is the action of methadone?
Agonist of mu-opioid receptor, with antagonism of NMDA receptor and inhibition of serotonin and noradrenaline reuptake indicated for opioid dependence or severe pain, however there is a risk of severe QT interval prolongation.
What is the action of buprenorphine?
Partial opioid agonist with affinity for mu-opioid receptor, with a slow onset of action and less adverse side effects compared to complete agonists. It is able to displace other opioids without producing an equal opioid effect, however individuals must be in a state of mild to moderate withdrawal.
