Pharm - Schizophrenia Flashcards
general MoA of antipsychotics
post synaptic blockade of brain dopamine D2 receptors
FGAs MoA
- D2 antagonists
- they lower neurotransmission in the 4 dopamine pathways
- they can also block H1, M1 and alpha1 receptors
SGAs MoA
- 5HT2A antagonists
- very high affinity for 5-HT2A
- lower D2 affinity than haloperidol
- dissociate rapidly from D2 receptors
adverse effect profile of FGAs vs SGAs
- FGAs: higher risk of neurological side effects
- SGAs: higher risk of metabolic side effects
common metabolic side effects of the antipsychotics
- weight gain
- hyperglycemia leading to DM
- hyperlipidemia
- hypertension
weight gain as an adverse effect of antipsychotics
-can be significant (.5 - 5 kg over 10 weeks)
monitoring parameter for weight gain and DM in a pt taking an antipsychotic
- monitor weight at every visit
- baseline weight and BMI
- BP
- fasting triglycerides/fasting lipids
- ask about family hx of DM
therapeutic management intervention for a pt who develops DM or significant weight gain
- can switch from a higher risk drug to lower risk
- metformin 1000-2000 mg/day
- lifestyle intervention
what risk increases in a pt taking a SGA?
- cardiovascular risk
- clozapine is associated w/ potentially fatal causes of myocarditis and cardiomyopathy
monitoring parameters and interventions to reduce cardiovascular risk (BP, lipids, DM)
- tx hyperlipidemia according to cardiovascular risk assessment (like a state)
- tx HTN according to current guidelines
orthostatic hypotension as an adverse effect of antipsychotics
- d/t the apha adrenergic blockage
- often accompanied by orthostatic tachy
- happens most commonly a few days after exposure or when dose is increased
monitoring parameters for orthostatic hypotension
- BP and HR should be monitored during intiation of tx
- at 3 months
- and annually thereafter
most appropriate therapeutic management intervention when a pt develops orthostatic hypotension
- usually self limiting
- possible slowing in rate of dose titration
- division of single daily dose into 2 or 3 small doses
- change in medication
increased QTc interval as an adverse effect of antipsychotics
-twice the risk of QT prolongation than someone not taking the drug
monitoring parameters for increased QTc interval
- get baseline EKG and serum K
- EKG at least annually, including at dose adjustments and changes in cardiac condition
- if FGA is lower risk, monitor EKG and potassium in those w/ hx of cardiac dz
appropriate therapeutic management intervention when pt develops increased QTc interval secondary to FGA
- dont initiate tx if baseline is > 450 ms
- during tx: if > 500 ms or increase of 60 ms or more = significant risk of torsades and warrants change in tx
- avoid using inhibitors of CYP-2D6 and drugs that prolong QT
sexual dysfunction as an adverse effect of the antipsychotics
-dysfunction is all phases of sexual activity
monitoring parameter for sexual dysfunction
- as specifically about difficulties w/ sexual function initially and annually
- evaluate prolactin if complaint
hyperprolactinemia as adverse effect of antipsychotics
-direct blockade of pituitary dopamine receptors allows uninhibited secretion of prolactin
monitoring parameters for hyperprolactinemia
-a serum prolactin level is indicated if the pt develops signs of sexual dysfunction or galactorrhea
serious allergic reactions are an adverse effect associated w/ what 2 drugs?
- ziprasidone
- asenapine
*warning has been issued regarding a potentially fatal drug reaction w/ eosiniphilia and systemic sx (DRESS)
agranulocytosis is an adverse effect of what drug?
clozapine
monitoring parameters for agranulocytosis
- for pts w/ pre-existing low cell counts or have had drug induced leukocytopenia in the past, monitoring is recommended during first few months of tx
- reasonable approach: ANC at baseline, after 1-2 weeks, and after 3-6 months
the fall risk with antipsychotics is related to what?
- sedation
- anticholinergic effects
- orthostatic hypotension
monitoring parameters for fall risk
-complete a fall risk assessment when initiating antipsychotic tx and recurrently for pts continuing on long-term antipsychotics
appropriate therapeutic management intervention w/ regards to sedation
- most severe early in tx (warn the pt)
- if they experience sedation they should be asked about it periodically
appropriate therapeutic management intervention w/ regards to anticholinergic effects
-for aggressive tx of constipation use prophylactic agents to prevent serious side effects like fecal impaction/bowel perf
EPS as an adverse effect of antipsychotics
- EPS sx include akathisia, parkinsonism, and dystonias
- MC with haloperidol, fluphenazine, thiothixene, and trifluoperazine
- uncommon w/: quetiapine, clozapine, and iloperidone
TD as an adverse effect of antipsychotics
- MC w/ haloperidol, fluphenzine, thiothixene, trifluoperazine
- not seen w/ clozapine
monitoring parameters for EPS
- evaluate weekly until medication dose is stable for 2 weeks
- then assess q 6 months
monitoring parameters for TD
- assess q 3-6 months throughout the course of tx, at shorter interval for high risk pts
- ask about restlessness, slow movements, shaking and rigidity at baseline and weekly w/ dose increases
- use AIMS to track development/progression of sx
most appropriate therapeutic management for a pt w/ EPS/TD
- only certain method of prevention is to avoid tx with antipsychoitcs
- if developed during tx immediately dc med if possible
- if you can’t dc: use SGAs over FGAs - use cross titration or maintain current med while titrating the new one
