Pharmacology of Schizophrenia Flashcards
What are antipsychotic medciations generally been in the past?
dopamine antagonists
dopamine is throuh =g to infleucne our behaviour to ensure survival and well being
how has the mesolimbic pathway been linked to schizoprenia?
hyperactive D2 (inhbitory)- leads to positive symptoms
VTA—-> mesolimbic (reward, additiocn, sensory processing)
what is the side effect of blocking the Mesolimib system in schizophrenia treatment?
how is the mesocortical dopamine pathway thought to be linked to schizophrenia?
hypoactive D1 (excitatory)- negative symptoms
what is the side effect of blocking the nigrostrial pathways
Nigrostrial pathway is invovled in inital and control of movvement (extrapyradmidal motor sysntem)
if we block dopamine, we have extrapyramidal symptoms
- hours/days- dystonia (tension in face/neck musclkes)
- days to weeks- Akathisia (restlessness)
- weeks to months- pseudo parkinsonisms (bradykinesiea, shuffling gait, tremor, rigidity)
- years- tardive dyskineaisa (oral and face movemesn, ultra sesntivie D receptors)
What is the effect of dopamine antagonism in the tuberoinfundibular pathway (hypothalamus-pituitary)
dopamine acts as a prolactin release inhbiting factor (PRIF)
preventing prolactin releasing factor (PRF) stimulating prolactin release from AP
side effects of blcoking this- sexual dysfunction, gynaecomasti, galactorrhoea, infertilitu
why od antispychotic cause other side effects?
very non specific to receptors so bind to other reeptors can cause issues
what side effects of antipsychotics may we see in the heart
Prolonged QTc
arrythmias—-> Cardiac arrest
thought to be due to blocking K+ channels invovled in repolarisation of ventricles
what major syndrome should be look out for in terms of antipsychotic medication side effects
Neuroleptic malignant syndrome
- labile BP
- tachycardiua
- sweating
- hyperthermia
- muscle rigidity—–> rhabodmyloysis—> renal failure
- can be fatal
cause- reduction central dopamienragic activity- more common in older, switching between antipsychotics and high does
what is the major side effects of 1st generation typical antispcyhotcis?
strong affinity for D2 receptors - More likely to produce movement disorders
what are the 3 major groups of 1st generation antiscphotics
Phenothiazines(3 groups of these, side effect based)
thioxantheses
butryophenoes
what drugs shoudl be avodied when taking phenothiazine (chlorpromazine)?
potentiates the sedative effect of benzodiazepines and central antihistomines
what is the main side effect of 2nd egneration/ atypical antipschotics?
weight gain and diabetes
need montiroing of BMI, Hba!c, ECG
name osme atypical antipsychotics
clozapinee
what drug is most effective for treatmetn agasint resistnatn (3rd line treatment) schizophrenia?
clozapine
