Psych Drugs Flashcards
What are the general signs of a anti-psychotic drug OD?
- Recently started or changed regime
- Cognitive impairment, headache and agitation
- Autonomic dysfunction = Pupils, temp, HR, BP and sweating
- Neuro = hyperreflexia, myoclonus and tremors
What are the signs of severe anti-psychotic OD?
- Rhabdomyolysis and AKI
- Seizures
- DIC
- Severe hyperthermia
- Cardiac arrhythmia
- Severe nausea and D&V
Cause specific signs?
- Muscle cramps and hyperkalaemia suggests Malignant Neuroleptic syndrome
- GI disturbances and hyperactive bowel suggests Serontonin syndrome
- Constipation, respiratory depression, Arrhythmia and hypotension suggests TCA overdose
- Severe nausea, D&V with neurological involvement suggests Lithium OD
What tests should you perform on these patients as standard?
- Basic Obs
- ECG
- Bloods = ABG, FBC, U&E, LFT, Clotting, Septic screen and toxicology
What are the basics of treatment for OD?
- ABCDE approach
- Stop offending drug (activated charcoal may reduce re absorption if OD taken recently) +/- fluids for dilution
- Control any hyperthermia (cooling blankets or fluid)
- Prevent AKI with IV hydration +/- diuresis
- Correct electrolyte imbalances
- Benzos if myoclonus/agitated/seizures
Cause specific Tx in more severe cases?
- SSRI = Serotonin antagonist (Olazapine) +/- Sedation (Diazepam) +/- paralytics + ventilation if severely hyperthermic (Vecuronium/Rocuronium)
- MNS = Dopamine agonist (Cabergoline/Bromocriptine)
- TCAs = Sodium bicarb (increases pH thus PP binding of TCAs), avoid anti-arrhythmics if possible but use drugs that don’t prolong depolarization/QT (Amiodarone) if required such as Magnesium
- Lithium = Haemodialysis
Describe the use of SSRIs (Citalopram, Sertraline, Paroxetine and Fluoxetine)?
- 1st line for moderate-severe depression (also used for anxiety disorders, OCD, PTSD and Bulimia)
- Give OD with 2-6 weeks until effects seen
Generic side effects
- GI = nausea, vomiting, anorexia, weight loss and diarrhoea
- Sexual = loss of libido and anorgasmia
- Hyper-excitability = restless, insomnia and irritability
- Hypersensitivity reactions
Severe side effect = serotonin syndrome
Describe the use of SNRIs (Venlafaxine and Duloxetine)?
- Used for depression when SSRI Tx fails and also for Anxiety disorders
Side effects
- GI = nausea, vomiting, anorexia, weight loss and constipation
- Sexual = loss of libido and anorgasmia
- Hyper-excitability = restless, insomnia and irritability
- Hypersensitivity reactions
- HTN and arrhythmia
- Raised cholesterol
Severe side effect = Serotonin syndrome
Venlafaxine contraindicated in Pregnancy, uncontrolled HTN and patients at risk of arrhythmia
Describe the use of Mirtazapine?
- Mirtazapine is a NASSA (NA and Selective Serotonin anti-depressant) which works by inhibuting alpha2 receptors -> loss of -Ve feedback on NA/Serotonin)
Indicated for depression
Side effects
- Increased appetite and weight gain
- oedema
- sedation
Recommended administration at night due to sedative effects
Describe the use of Reboxetine?
- Reboxetine is a NARI (NA ruptake inhibitor) used for depression
Side effects
- Antimuscarinic = dry mouth, palpitations/tachycardia, constipation and urinary retention
- Insomnia
Describe the use of TCAs
- TCAs inhibit both NA and serotonin reuptake
- They are used for depression but also: neuroleptic pain (Amitriptyline), paediatric nocturnal enuresis (Imipramine) and OCD (Clomipramine)
Side effects
- Antimuscarinic = dry mouth, visual disturbances, constipation and urinary retention
- Drowsiness
- Toxicity = Constipation, hepatic impairment, respiratory failure, arrhythmia and hypotension
Contraindicated if CVD, hepatic impairment or bipolar
Describe the use of MoAi?
- Phenelzine is a MAOi that decreases the breakdown of NA and serotonins within pre-synaptic neurone
- Indicated for refractory/atypical depression
Side effects
- Anti-muscarinic
- Increased appetite and weight gain
- Hypotension
Severe side-effects = HTN crisis and serotonin syndrome
Contraindicated in mania, CVD or liver disease
Do not start another anti-depressant within 2 weeks of stopping a MAOi
Do not start a MAOi within 1 week of stopping a different anti-depressant
Avoid foods rich in tyramine due to increased MAOi affect
Describe the use of Lithium?
- The action of lithium is unknown but it is used in acute mania, prophylaxis of BPAD and in augmented anti-depressant therapy
Side effects
- General = weight gain, oedema, weakness, tremor and worsening of acne/Psoriasis
- Endo = hypothyroidism and hyperparathyroidism
- Cardio = T-wave inversion
- GI = nausea, vomiting, diarrhoea and metallic taste
- Renal = nephrogenic DI with long-term use -> impairment
- Haem = leucocytosis
Sodium valproate should not be used in pregnancy and with caution in CVD and renal impairment
Prescribing
- TFTs, bone profile, ECG, U&E, LFT, FBC and pregnancy test before prescribing
- Optimise drug chart due to interaction with NSAIDs and ACEi
- Monitor above and Lithium levels (0.6-0.8/1 mmol/L = therapeutic, side effects more pronounced >1.2 and toxic above 1.5)
Describe the use of sodium valproate?
The MoA of sodium valproate is unknown but it is used in acute mania, prophylaxis of BPAD, Epilepsy and refractory depression
Side effects
- General = nausea, vomiting and weight gain
- Hair loss
- 3 Ps (pancreatitis, hepatic failure and pancytopenia)
Contraindications
- 3 Ps (Pregnant, hepatic failure and Porphyria)
Prescribing
- LFTs and pregnancy before and monitor LFTs
Describe the use of Carbamezapine?
MoA = Na channel blocker
Used for prophylaxis of BPAD, Epilepsy and trigeminal neuralgia
Side effects o Rash = common but rarely serious o Neuro = headache, dizziness, diplopia and ataxia o GI = nausea, vomiting, anorexia and diarrhoea o Haem = cytopenias and agranulocytosis/aplastic anaemia in 1/20,000 o Hyponatraemia (SALT LOSS) o Spina bifida and developmental defects to foetus
Contraindications o Pregnancy o Bone marrow depression o Acute Porphyria o Pacing abnormalities
Prescribing notes
o Requires FBC, ECG and pregnancy test before prescribing
o Regular FBC and ECG monitoring
