Psycho Drugs Flashcards
What drugs are used in epilepsy?
Sodium valproate
Carbamazepine
Lamotrigine
Benzodiazepines and phenytoin
*all sodium channel blockers exclu. Benzodiazepines
Describe the management of status epileticus under 10 mins
ABCDE approach-stabilise
Benzodiazepines (further dose if not terminating within 5 mins)
Exclude hypoglycaemic causes
Describe the management of status epilepticus lasting over 10 minutes
(Same as before 10 minutes plus…)
Call ITU and Med specialist registrar
Give loading dose of IV phenytoin
What do you need to look out for when giving a IV loading dose of phenytoin?
Arrhythmias and hypotension
How should you manage pt taking anti-epileptics whilst pregnant?
Give folate supplements (prior to conception)
Vitamin K supplements in T3
What drugs are given for Parkinson’s?
Levodopa + Carbidopa Dopamine receptor agonists COMT inhibitor Anticholinergics Amantidine
What drugs can be used to treat myasthenia gravis?
ACh esterase inhibitors Corticosteroids Steroid sparing (azathioprine) IV Ig Plasmapheresis
What drugs are used to treat depression?
SSRIs (1st line)
TCAs
SNRIs
MAOIs
What is the advice given for length of treatment with depression and why?
Try for at least 6 wks before switching drugs
And continue medication for 1yr despite feeling better to reduce risk of relapse
What drug is used to treat schizophrenia?
Antipsychotics/ dopamine antagonists
atypical are 1st line
What are the extrapyramidal side effects of antipsychotics?
Dystonia (sustained or repetitive muscle contraction)
Akathisia (restlessness)
Tardive dyskinesia (involuntary repetitive movements)
Pseudo-Parkinsonism
What is the treatment for anxiety?
Anxiolytics (benzodiazepines short term)
Antidepressants
Occasionally antipsychotics
Describe the management of a benzodiazepine overdose
Flumazenil:
Antagonist at BDZ receptors
Bipolar disorder is a spectrum that consists of what?
Mania
Hypomania
Depression
Why aren’t antidepressants given to people with bipolar disorder?
Pushes them to mania
What drugs are used for bipolar disorder?
Mood stabilisers; Li Sodium valproate Carbamazepine Lamotrigine Antipsychotics
What is the management for Li toxicity?
Anti-convulsants
Increase fluid intake/IV fluids
Haemodialysis (may be necessary)
What drugs can be given for dementia?
ACh esterase inhibitors
Memantine (NMDA antagonist)
Give 3 examples of benzodiazepines and how they are given
Lorazepam- IV
Midazolam- buccal
Diazepam- rectal
What is the mechanism of action of benzodiazepines?
Enhances action of GABA
Less excitable neurones (Cl-)
Decrease chance of reaching seizure threshold
Why are benzodiazepines not for long term use?
Increased ADRs as time continues
Tolerance build up
Dependence
Withdrawal-triggers seizures
What is sodium valproate used for?
Epilepsy - partial, generalise tonic-clonic, absence
Bipolar disorder
What are the ADRs of sodium valproate?
Teratogenic CNS dysfunction Hepatic failure (rare)
What is carbamazepine used for?
Epilepsy- Tonic clonic And all Partial seizures
Bipolar disorder
What are the ADRs of carbamazepine?
Dizziness, drowsiness, ataxia, Motor disturbance, numbness and tingling
What are the contraindications of carbamazepine?
AV conduction problems
Antidepressants
What is phenytoin used for?
Generalise tonic-clonic, all partial seizures
Status epilecticus
ADRs of phenytoin?
Dizziness Ataxia Headache Gingivial hyperplasia Rash (Steven Johnson’s syndrome 2-5%)
What is lamotrigine used for?
Epilepsy: all partial seizures, tonic-clonic and absence
Bipolar disorder
What are the benefits of lamotrigine?
Less marked CNS side effects
Safer in pregnancy
What is the mechanism of action for L-dopa?
Crosses BBB
Taken up by dopaminergic cells in Substantia nigra
Converted to dopamine (dopa decarboxylase)
ADRs of L-dopa?
Dyskinesia Dystonia Freezing Psychosis Nausea Vomiting Hypotension
What is the mechanism of carbidopa?
Used with L-dopa
Peripheral decarboxylase inhibitor
Thus prevents breakdown of L-dopa in peripheries
*COMT inhibitor does the same thing
What are the benefits of using carbidopa with levodopa?
Reduces dosage of L-dopa
Decreases peripheral side effects
How do anticholinergics treat Parkinson’s?
(Minor treatment)
ACh has antagonist effect on dopamine
Treats tremors but no effect on bradykinesia
What are ADRs of anticholinergics?
Confusion
Drowsiness
Dry mouth
Urinary retention
What are acetylcholine esterase inhibitors used for?
Myasthenia Gravis
Dementia (mild-moderate)
What is the action of acetylcholine esterase inhibitors?
Enhances neuromuscular transmission
By preventing breakdown of ACh
What are side effects of cholinergic drugs?
SSLUDGE: Sweating Salivation Lacrimation Urinary incontinence Diarrhoea GI upset Emesis
What are side effects of anticholingergics?
Can’t see- no lacrimation
Can’t pee-urinary retention
Can’t spit- no salivation
Can’t shit- constipation
What are the mechanism of SSRIs?
Limits reuptake of serotonin into presynaptic neurone
Increases serotonin levels in synaptic cleft
More neurotransmission
Side effects of SSRIs?
NV
Sexual dysfunction
Insomnia
What is serotonin syndrome?
A life threatening presenting within a few weeks of initiating SSRIs or when two are used at once. Causes: Tachycardia Sweating Dilated pupils Myoclonic seizures Hyper reflexes Hyperthermia
What are the mechanism of action of tricyclics antidepressants?
Same as SSRIs
PLUS
Blocks ACh action (anti-muscarinic)
Why cant TCAs if the pt is suicidal?
Cause they lethal in overdose due to toxic effects
When do you use SNRIs?
In depression when SSRIs haven’t worked
What are the different effects of SNRIs at different doses?
Low dose- serotonin action- anti-depressive effect
High dose- NA action as well- anxiolytics effect
What is the difference between typical and atypical antipsychotics?
Typical - dopamine antagonists
Atypical - serotonin agonists and dopamine antagonists
What are antipsychotics used for?
Schizophrenia
Bipolar disorder
Side effects of antipsychotics?
Anti cholinergic nausea Sexual dysfunction Insomnia Obesity Extrapyramidal side effects
What is neuroleptic malignant syndrome?
Life-threatening reaction within 2 weeks of initiating anti-psychotics Fever Altered mental status Hypertonia Autonomic dysfunction
What are the contraindications of lithium?
Renal failure
ACE inhibitors
NSAIDs
What is the action of lithium?
Increases serotonin
What are the side effect of lithium?
Memory problems Thirst Polyuria Tremor Drowsiness Weight gain
Give an example of an example of an NMDA receptor blocker?
Memantine
What are the side effects of memantine?
Hypertension Dyspnea Headaches Drowsiness Dizziness
What is the action of NMDA receptor blockers?
Reduces neurotoxic effects of dementia
Exerts modest effect on slowing down progression
