psychdrugs Flashcards
which receptor do SSRIs work on?
5HT
what are the side effects of SSRIs?
nausea vomiting diarrhoea agitation insomnia
how to prevent serotonin syndrome?
stop ssris 2 weeks before starting maois
what is the triad of symptoms for serotonin syndrome?
autonomic instability - fever, hypotherm, sweating, bp
neuromuscular excitability
altered mental status
how is serotonin syndrome treated?
stop drug
anti-hypertensives
benzodiazepines
how is severe serotonin syndrome treated?
chlorpromazine / cyproheptadine
How long does it take for SSRIs to work?
4-6 weeks
when to review SSRIs?
2 weeks
1 week if suicidal/under 30
which receptors does TCA bind to?
H1 histamine receptor - sedation
Muscarinic ACh inhibitor - cholinergic SEs
alpha-adrenergic - postural hypotension
which arrhythmias does TCA cause?
tachy, then wide complex tachy, then ventricular arrhythmias prolonged QRS (>2 small boxes)
what is the main cardiovascular risk of TCAs?
prolonged qrs
how is prolonged qt treated in tcas?
iv sodium bicarbonate
what are the side effects of TCAs
arrhythmias sedation postural hypotension dry mouth constipation blurred vision
what are the side effects of lithium?
Lethargic Insides - GI disturbance Tremor (fine, if tox, coarse) Hypothyroidism Insipidus - polyuria, dipsia, normal glucose! Urine - as above Metallic taste
which tremor is seen as a side effect of lithium?
fine tremor
which tremor is seen as a side effect of lithium toxicity?
coarse tremor
what pathways is dopamine involved in?
mesolimbic
mesocortical
nigrostriatal
tuberoinfundibular
how is the mesolimbic pathway affected in psychosis?
increased dopamine leads to positive symptoms of psychosis
how is the mesocortical pathway affected in psychosis?
decreased dopamine in mesocortical - negative symptoms - apathy, etc
how is the nigrostriatal pathway affected in psychosis?
nigrostriatal is responsible for initiating movement
not affected in psychosis
how is the tuberoinfundibular pathway affected in psychosis?
dopamine inhibits prolactin
normal in psychosis
how do antipsychotics affect the tuberoinfundibular pathway?
decreased dopamine - increased prolactin - galactorrhoea
how do antipsychotics affect the nigrostriatal pathway
decreased dopamine, parkinsonism and EPSEs
why do first gen antipsychotics have more side effects?
less selective, affect the tuberoinfundibular and nigrostriatal pathways too.
list some typical antipsychotics?
haloperidol
flupentixol
zuclopenthixol
chlorpromazine
list some atypical antipsychotics
olanzipine
risperidone
quetiapine
aripiprizole
what class of drug is clozapine?
atypical atypical
which two antipsychotics are most associated with weight gain?
olanzipine and clozapine
what are the side effects of antipsychotics
weight gain reduced seizure threshold anticholinergic side effects prolonged QT neuroleptic malignant syndrome
How is NLMS differenitated from serotonin syndrome
nlms = has raised CK, slower onset Serotonin = has hyperreflexia, dilated pupils, faster onset
what are the symptoms of nlms?
rigidity increased wcc increased CK variable bp fever tachy sweating altered mental state
what is the treatment for nlms?
stop antipsychotic, supportive
what triggers serotonin syndrome?
mix SSRI
cocaine
ecstasy
what are the side effects of clozapine?
agranulocytosis
constipation - paralytic ileus
myocarditis - chest pain
what do you monitor for clozapine/
fbc
ecg
which drugs interact with antipsychotics?
levodopa cancels out
metoclopramide increases EPSEs
antiepileptics, antibiotics (clarithromycin)
drugs that prolong qt - citalopram
