Antipsychotics III (specific antipsychotics, tables) Flashcards
what is the half life of haldol
12-38 hours PO
3 weeks IM (long acting)
indications for haldol use
schizophrenia
bipolar disorder
behavioural disturbances in dementia
acute agitation
tics and vocal utterances in Tourettes disorder
starting dose of haldol
2mg po
titration of haldol
2mg po q2weeks
maximum dose of haldol
15mg po (max 25mg)
what is the dose of haldol to use if using it to manage acute agitation
2-5mg q1h PO/IM (max 20mg/24hours)
which is the most second generation-like FGA
loxapine
which is the most first generation-like SGA
risperidone
which APs are approved by health canada for pediatric uses
chlorpromazine
haldol
which AP has been banned by health canada for cardiac arrhythmia risk
thioridazine
loxapine is not recommended below what age
below 16
in general, how is metabolism of APs different in children from adults
quicker metabolism in children compared to adults (i,e which is why you see BID/TID dosing of APs in kids… they have shorter half life in kids)
what is the T1/2 of risperidone in kids compared to adults
kids–> 2 hours
adults–> 12-24 hours
which SGAs need to be taken with food
ziprazidone and lurasidone
which AP is the LEAST toxic in the context of liver failure
paliperidone
what should you think if someone is on clozapine and has elevated prolactin
theyre probably SEIZING
clozapine shouldnt cause much, if any, prolacting increase but DOES markedly lower seizure threshold
what side effect is quite specific to quetiapine
hypothyroid
what side effect is quite specific to olanzapine
impaired insulin
what enzymes metabolize risperidone
CYP 2D6 and 3A4
does risperidone have higher affinity for 5HT2A receptors or D2 receptors?
higher affinity for 5HT2A
on which receptors does risperidone act
D2
5HT2A
alpha 1
alpha 2
H1
(antagonism)
list indications for risperidone
schizophrenia
bipolar I
bipolar II
MDD (adjunctive)
OCD
BPSD
ASD (risperidone–should use low doses)
what is the maximum dose of risperidone
16mg
how long does it take for risperidone consta (IM long acting) to take effect
21 days
therefore requires 21 days of oral supplementation when starting treatment with IM formulation
what is the oral equivalent of 25mg IM risperidone
risperidone 25mg IM is = to about 2-3mg oral risperidone
care must be taken when prescribing risperidone with a particular SSRI. which SSRI is this? why?
fluoxetine
because concomitant Rx can increase plasma concentrations of risperidone by 2-3x as fluoxetine is CYP 2D6 inhibitor (which metabolizes risperidone)
*sertraline is also a moderate inhibitor but may increase levels of risperidone but not levels of the active metabolite
at what doses dose risperidone act more like a FGA
6-8 mg (higher doses)
this is a dose responsive relationship with dose and incidence of EPS
do you need to be careful with risperidone in renal impairment
yes–> start lower, use split doses, slower titration
why do we consider the blockade of 5HT2A receptors a positive thing with risperidone
causes enhancement of dopamine release in certain brain areas–> thus reduces motor side effects and possibly improves cognitive and affective symptoms
list 5 FDA approved indications for risperidone
schizophrenia
delaying relapse in schizophrenia
other psychotic disorders
acute mania (oral, monotherapy or with lithium/valproate)
ASD related irritability in kids 5-16
also indicated for:
bipolar maintenance
bipolar depression
behavioural disturbances in dementias
behavioural disturbances in kids and teens
disorders associated with impulse control
how quickly should you up-titrate risperidone
about 1mg per week on inpatient
what is the therapeutic range of risperidone for acute psychosis and bipolar disorder
2-8mg per day PO (risk of EPS higher above 6mg)
what is the therapeutic range for risperidone in kids or the elderly
0.5-2mg po daily
what is the starting dose of risperidone consta
25mg IM q2weeks
what is the max dose of risperidone consta
50mg IM q2weeks
what monitoring should be done for risperidone
weight/BMI
waist circumference
BP
lipid profile
fasting glucose
prolactinn levels when indicated
is risperidone generally lethal in monotherapy overdose
rarely
could see sedation, rapid HR, convulsions, low BP, difficulty breathing
other than fluoxetine and sertraline, what other antidepressant should be used with caution with risperidone
buproprion (also CYp 2D6 inhibitor)
how many LAI injections of risperidone are needed to achieve steady state
4
does risperidone prevent recurrences of mania in bipolar disorder
yes
what is the most frequently used AP in kids
risperidone
*but safety and efficacy not well established in data
what is the increased risk of cerebrovascular events in the elderly when using risperidone
base 1/100 per year to 2/100 per year
what is the increased mortality associated with dementia related psychosis
from base 1/100 per year to 2/100 per year….
what do the early findings show with regard to risperidone use in pregnancy
early findings show infants exposed to risperidone in utero do not show adverse consequences
may be preferable to anticonvulsant mood stabilizers if tx required during pregnancy
where does a significant portion of paliperdone metabolism occur
in the kidneys
why is paliperidone best in patients with hepatic failure
because it is an active metabolite so does not undergo much metabolism in the liver
starting dose of paliperidone
3mg po daily
increase by 3mg every 7 days
what is the maximum dose of paliperidone PO
12mg
where must invega sustenna IM doses be given to achieve higher plasma concentrations
in the deltoid
NOT the gluteal
how are paliperidone loading doses administered
standard for all patients
150mg IM day 1 and 100mg IM day 8
(150mg of paliperidone is given as 234 mg of paliperidone palmitate)