Mental Health Drugs Flashcards
Tricyclic anti-depressant examples
Amitriptyline, lofepramine
Tricyclic anti-depressant indications
- Second line treatment for moderate - severe depression where SSRIs ineffective
- Treatment for neuropathic pain (not licensed)
Tricyclic anti-depressant MOA
- Inhibits neuronal re-uptake of serotonin and noradrenaline from synaptic cleft, increasing their availability for neurotransmission
- Block a wide range of receptors including muscarinic, histamine, alpha-adrenergic and dopamine - accounts for extensive adverse effects profile
Tricyclic anti-depressant contraindications
Used with caution in people at high risk of side effects:
- Elderly
- CVD
- Epileptics
- Constipated
- Prostatic hypertrophy
- Raised intra-ocular pressure
Tricyclic anti-depressant side effects
- Blockade of anti-muscarinic receptors: dry mouth, urinary retention, blurred vision
- Blockade of alpha-adrenergic receptors: sedation and hypotension
- Cardiac adverse effects: arrhythmias, prolonged QT and QRS
- Neurological changes: convulsions, hallucinations and mania
- Dopamine receptor blockade: breast changes, sexual dysfunction
- Extrapyramidal symptoms: tremor, dyskinesia
- Overdose: hypotension, arrhythmias, convulsions, coma, respiratory failure
- Sudden withdrawal: GI upset, neurological and flu-like symptoms, sleep disturbance
Tricyclic anti-depressant interactions
- MOA inhibitors: both increase serotonin and noradrenaline at synapse - precipitates hypertension, hyperthermia, serotonin syndrome
- Augment anti-muscarinic, sedative, hypotensive adverse effects of other drugs
Tricyclic anti-depressant patient information
Takes a few weeks to notice improvements
Symptoms may worsen initially
Discuss psychological therapies
Treatment must be continued for 6 month minimum
SSRIs examples
citalopram, fluoxetine. sertaline, escitalopram
SSRIs indications
- 1st line for moderate / severe depression
- Mild depression after failure of psychological therapy
- OCD
SSRIs MOA
- Preferentially inhibit neuronal re-uptake of serotonin from the synaptic cleft, increasing its availability for neurotransmission
- Differ to tricyclics: do not inhibit noradrenaline uptake, cause less blockade of other receptors
- Efficacy between 2 classes similar but SSRIs preferred due to fewer adverse effects
SSRIs contraindications
Prescribed with caution where particular risk of adverse effects:
- epilepsy
- peptic ulcer disease
Young people:
- decreased efficacy
- increased risk of self-harm and suicidal thoughts
Metabolised by liver so reduced dose in hepatic impairment
SSRIs side effects
- Common: GI upset, appetite and weight disturbance, hypersensitivity reactions (skin rashes)
- Elderly: hyponatraemia which may present as confusion and reduced consciousness
- Increased suicidal thoughts and behaviours
- Lower seizure threshold
- Citalopram prolongs the QT interval so can predispose to arrhythmias
- Increased risk of bleeding
- Serotonin syndrome: when taken at high doses / combined with other anti-depressants / overdose. Triad consisting of:
-autonomic hyperactivity
-altered mental state
-neuromuscular excitation
Usually responds to withdrawal of treatment and supportive therapy. - Sudden withdrawal: GI upset, neruological and flu-like symptoms, sleep disturbance
SSRIs interactions
- MOIs: both increase synaptic serotonin levels = serotonin syndrome.
- NSAIDs / aspirin: increased risk of GI bleed, must offer gastroprotection
- Anti-coagulants: increased risk of bleeding
- Other drugs that prolong QT interval e.g. antipsychotics
SSRIs patient info
Takes a few weeks to notice improvements
Symptoms may worsen initially
Discuss psychological therapies
Treatment must be continued for 6 month minimum
Benzodiazepines examples
Diazepam, lorazepam, midazolam, chlordiazepoxide