Pharmacology Flashcards
Antidepressants (types and examples)
SSRI – citalopram TCA – Amitriptyline SNRI – venlafaxine SARI – trazodone MAOi - Selegiline OTC – St John’s wort NaSSA – Mirtazapine
All work on monoamines within the brain. Can be used to treat depression or anxiety disorders
- SSRIs are considered first line for depression
- TCAs increasingly being used in the management of chronic pain
(SSRIs, NaSSAs Safer in overdose, TCAs, MAOi More dangerous in overdose)
side effect of antidepressants
SSRIs – GI disturbance, insomnia, hyponatraemia, agitation, dry mouth, headaches, discontinuation syndrome, serotonin syndrome
TCAs – Dry mouth, constipation, Prolonged QTc/arrhythmias, sedation
SNRIs – Dizziness, dry mouth, nausea, sweating, agitation
SARIs – Fatigue, constipation, dizziness, dry mouth, headaches, blurring of vision
MAOi – Tyramine reaction, dry mouth, nausea, GI disturbance, dizziness
NaSSAs – Increased appetite, sedating (particularly at low doses), neutropenia, agranulocytosis
St John’s Wort (OTC) – CYP inducer, fatigue, dry mouth
what is seretonin syndrome?
Medical emergency caused by enhanced serotonin transmission within the brain
Agitation GI overstimulation Tremor Myoclonus Fever Impaired consciousness BP & pulse instability
Creatinine Kinase can be elevated
Risk of serotonin syndrome is increased if patient using cocaine, LSD, St John’s Wort or co-prescribed with other antidepressants, lithium and/or MAOIs
what is tyramine reaction?
- Monoamine oxidase can be found in the gut as well as the brain. Usually breaks down tyramine found in foods
- Inhibition of this results in an excess of tyramine within the body
- Increased tyramine causes an increase in noradrenaline
- Resulting in a sudden & sometimes extreme rise in BP, flushing, headaches and indigestion
what is neuroleptic malignant syndrome?
Classically associated with typical antipsychotics, but can occur in patients on atypicals
Within the first two weeks, patients present with
Pyrexia
Muscle rigidity
Autonomic instability (BP, pulse)
Fluctuating level of consciousness
Creatinine kinase raised
Treatment requires physiological support and removal of antipsychotics for a minimum of two months
neurleptic malignant syndrome
Vs
serotonin syndrome
neuroleptic malignant syndrome •Hyporeflexia •Bradykinesia •Lead pipe rigidity •Fluctuating consciousness
seretonin syndrome •Agitation •Hyperreflexia •Hyperkinesia •Shivering •Increased bowel sounds
examples of mood stabilisers (and the side effects)
Lithium (gold standard), anticonvulsants, antipsychotics
Lamotrigine: used to treat epilepsy or bipolar when depression is the main problem (not recommended for mania)
tablet/dispersible
Rashes, can develop Steven- Johnson’s Syndrome
Carbamazepine
CYP inducer, hyponatraemia, leukopenia
Sodium valproate
lithium
1st choice in mania episodes and long term. should check levels every 3-6 months
aim for level 0.6-1.0mmol/L
Comes in 2 forms: • Tablets – Lithium carbonate 1. Camcolit – Treatment – 1-1.5g daily and as prophylaxis 300-400mg a day. 2. Priadel 3. Liskonum • Liquid – Lithium citrate 1. Priadel liquid 2. Li-liquid
side effects: hypothyroidism cardiac arrhythmias GI upset diabetes insipidus thirst teratogenic in pregnancy renal failure polyruia
lithium toxicity
mild/moderate >1.5mmol/L Nausea Diarrhoea Ataxia Drowsiness Coarse tremor
severe toxicity >2mmol/L Disorientation Seizures Coma Death
benzodiazepines and Z drugs
Benzodiazepines are agonists for GABA receptors (GABA = inhibitory neurotransmitter)
Shorter acting
Lorazepam
Diazepam
Longer-acting
Clonazepam
Chlordiazepoxide
Z drugs
Zopiclone
Zolpidem
what are the side effects of benzo’s?
Drowsiness Dizziness Risk of falls – particularly in the elderly Memory impairment Paradoxical agitation Reduced psychomotor function Can reduce respiratory rate in overdose Risk of tolerance and addiction
features of benzo withdrawal
Common
Anxiety, Insomnia, Restlessness, tension
Less common
Nausea, sweating, blurred vision, nightmares
Rare features:
Hallucinations, seizures, tinnitus, paranoia
mood stabilisers
indicate to help out highs/lows in manic and depressive episodes such as bipolar, schizoaffective disorder, personality disorder.
can be taken short term or long term
lithium contraindications
- Addison’s disease
- Cardiac disease associated with rhythm disorder
- Cardiac insufficiency
- Dehydration
- Low sodium diet
- Untreated hypothyroidism
Salt consumption can cause fluctuations in serumlithium levels. While takinglithium, do not make sudden changes to your salt intake. A sudden decrease insodiumintake (a component of salt) may result in higher serumlithium levels, while a sudden increase insodiummight prompt yourlithium levelsto fall.
sodium valporate
*used if lithium is unsuitable or unaffective. treat epilepsy and mania.
Diarrhoea, hair loss, weight gain, peripheral oedema
can cause increased testosterone (can stop periods, abnormal hair growth, PCOS, should not be perscribed in pregnancy, LFT’s stat and 6 months)
antipsychotics in bipolar
- Olanzapine
- Haloperidol
- Quetiapine
- Risperidone
Side Effects: • Aggression • Joint Pain • Agitation • Vomiting and diarrhoea • Drowsiness • Dizziness • Dry mouth • Tiredness • Irritability • Headaches • Tremors • Sleep problems.
stopping mood stabilisers, effect on other meds + breasfeeding
Stopping Mood Stabilisers:
• Reduce the dose slowly over a few weeks
• Look for withdrawal symptoms
Effects on other medications:
• Codeine
• Paracetamol
• Iboprofen
Alcohol is not recommended
Breastfeeding – antipsychotics should be used
Tardive dyskinesia
Involuntary muscle movements- usually affecting tongue, lips, trunk and extremities. seen in patients who are on long term anti dopaminergic meds such as antipsychotics medication (typica/atypical) some antidepressants, metaclopromide, prochhloperazene, carbamezapine, phenytoin
stiff and jerky movements of body and face. blink/stick out tongue, wave arms
caused by halopreidol, chlorpromazine (antipsychotics)
can also give extrapyramidal side effects
e.g. bradykinesia
seretonin syndrome
OD or combo of SSRI’s / SNRI’s
3 of the following:
ataxia, diarrhoea, hypereflexia, agitation, tremor, clonus, change in mental status
complications:
renal failure, respiratory failure, rhabdomyolysis, arrhythmia’s
supportive mx
akathisia
restlesness
associated with antipsychotic use
inability to remain motionless
neuroleptic malignant syndrome
antipsychotic meds
life threatening
hyperthermia, muscle rigidity, change in level of consciousness, autonomic instability.
mx: discontinuemeds, dantrolene, bromocriptine. solve in 1-2 weeks
acute dystonia
spasm in various muscle groups caused by haloperidol (few hours after administration)
treatment- anticholinergics
important notes for starting on SSRI
Increased risk of suicidal thinking and self harm in <30 y/o
Benefit 4-6 weeks after SSRI but full benefit can take 12 weeks
Seen every 2-4 weeks for first 3 months after starting meds, every 3 months after
discontinuation symptoms:
ebound enxiety, depressive symptoms, flu like symptoms, dizzy, nausea, sleep disturbances if stop SSRI abruptly
ECT
catatonia
Severe depression
Prolonged or severe mania
Not recommended in schizophrenia
clozapine
1st line is olanzoopine
2nd line clozapine (started on specialist advice if other antipsychotic meds have not been effective) ! risk of agranulocytosis !
if missed for >48 hours, restart with dose of 12.5mg (can be titrated more rapidly if patient is clozapine-naive)
treatment for hypersalavation (a side effect of clozapine)
most commonly occurs in first 4 weeks, can wear off but can persist. worse at night
can be a cause of aspiration pneumonia
tx: hyoscine
management of insomnia
tx: zopiclone
melatonin is given in children or adults with learning difficulties as they often have chronic sleep-wake cycle disruptions.
promethazine can be given for agitation or insomnia and helpful in maintaining sleep/
methadone
given to patients dependent on illicit opioids (heroin)
full opioid agonist
alternative- buprenorphine (partial opioid agonist)
important to check before starting on antipsychotics
weight, waist circumference, BP, Hba1c, fasting glucose, lipid levels, prolactin levels, diet and exercise, movement disorder
