13. Psychopharmacology Flashcards
Name 3 types of drugs you could use to manage anxiety disorders.
- SSRIs
- benzodiazepines
- GABA analogues, e.g. pregbalin
Why are benzodiazepines only used for short-term relief of severe anxiety?
- many side effects, e.g. sedation, confusion, aggression
- long term use causes tolerance and dependence
- can make Ps more likely to act on suicidal impulses
What would be the effects of a benzodiazepine OD and how could this be managed?
Effects: respiratory (decreased RR) and CNS (sedation, coma) depression
Can be reversed by IV flumazenil (antagonist/partial agonist at BDZ R) but use may precipitate seizure/arrhythmia.
What are the 2 main types of drugs used to manage schizophrenia? How is their MOA different?
- Typical antipyschotics, e.g. Haloperidol, Chlorpromazine
- act predominantly as D2 R antagonists
- also have anti-cholinergic effects, alpha-adrenoR blockers, anti-histamine effect - Atypical antipsychotics (1st line), e.g. Risperidone, Clozapine
- act as D2 R antagonists (lower affinity)
- act as serotonin R agonists
What is the effect of typical antipsychotics D2 R blockage in the different dopamine pathways of the CNS?
- Mesolimbic pathway: dramatic therapeutic action on +ve psychotic symptoms
- Nigrostriatal pathway: extra-pyramidal side effects
- Mesocortical pathway: enhanced negative and cognitive psychotic symptoms
- Tuberoinfundibular pathway: hyperprolactinaemia (galactorrhea, infertility, sexual dysfunction)
What are extra-pyramidal side effects?
Caused by all dopamine antagonists but more prominent in typical antipsychotics as these largely act on D2 Rs, inc. nigrostriatal pathway:
- DYSTONIA - sustained muscle contraction resulting in abnormal fixed posture
- AKATHISIA - internal feeling of restlessness
- TARDIVE DYSKINESIA - abnormal involuntary repetitive movements, e.g. grimacing, lip smacking, sticking out tongue
- PSEUDO-PARKINSONISM - rigidity, tremor and increased tone
