Schizophrenia Flashcards
Negative Symptoms
blunted emotion
poor self-care
social withdrawal
poverty in speech
Positive Symptoms
hallucinations
delusions
bizarre behavior
thought disorders
Cognitive Symptoms
- decrease in cognitive function
- involves D1 receptors and glutamate receptors
Serotonin Hypothesis of Schizophrenia
- LSD and mescaline were identified as 5HT agonists
- 5HT2A receptor as mediator of hallucinations
- antagonism and inverse agonism linked to antipsychotic activity
Which receptors modulate dopamine release in cortex, limbic region, and striatum
5HT2A receptors
Which receptors modulate glutamate release and NMDA receptors
5HT2A receptors
Glutamate Hypothesis of Schizophrenia
- glutamate is major excitatory neurotransmitter
- phencyclidine and ketamine, noncompetitive inhibitors of NMDA receptors exacerbate psychosis and cognition deficits (increasing symptoms)
Dopamine Hypothesis of Schizophrenia
- D2 receptor antagonists
- dopaminergic agents exacerbate symptoms of schizophrenia
- increased D2 receptor density in treated and untreated patients
-D2 receptor antagonists initially increase metabolites in the CNS and later decrease metabolites in the CNS
Major Receptors Antagonized by Antipsychotics
Dopamine
D1 like = 1 and 5
D2 like = 2, 3, 4
5HT2A Receptor Antagonists
clozapine
olanzapine
risperidone
Older 5HT agents
chlorpromazine
haldol
thioridazine
Norepinephrine Alpha 1 Blockade Effects
hypotension, sedation
Norepinephrine Alpha 2 Blockade Effects
may be helpful in therapy
Acetylcholine Effects
anticholinergic effects
clozapine, thioridazine
Histamine Effects
H1 Receptor Antagonists
sedation, weight gain
Correlation between binding potency and clinical effectiveness for ________ receptors, therefore more _______ drug target
D2; effective
Most antipsychotics drugs are receptor _______
antagonists
D2 ____ D1 receptor binding
>
D2 Receptor Antagonist
blocks both pre and post-synaptic receptors
at first, Pre-synaptic blocked: increases the synthesis and release of dopamine
when dopamine diffuses back into the presynaptic receptor, it tells the receptor there is way too much dopamine, presynaptic receptor decreases synthesis
Dopamine Physiology and Function: Mesolimbic
primary therapeutic effects
D2 Receptor occupancy and rate of EPS as functions of plasma risperidone concentration
increased concentration of risperidone –> increased D2 occupancy –> increased EPS
EPS
extrapyramidal symptoms
Symptoms of EPS
dystonia (increased muscle tones)
pseudoparkinsonism (muscle rigidity)
tremor
akathisia (restlessness)
When does EPS occur?
early, days/weeks, reversible
Drug Therapy for EPS
benztropine, trihexyphenidyl, akineton (anticholinergic)
diphenhydramine (antihistamine)
amantadine (dopamine release agent)
propranolol (used for akathisia)
Tardive Dyskinesia
occurs late, months to a year
irreversible
Symptoms of Tardive Dyskinesia
rhythmic involuntary movements
choreiform: irregular purposelessness
athetoid: worm like
axial hyperkinesias: to and fro movements
MOA of Tardive Dyskinesia
unknown
Monitoring of Tardive Dyskinesia
AIMS (abnormal involuntary movement scale)
check q6months
Treatment of Tardive Dyskinesia
prevention
1. reduce dose of current agent
2. change to a different drug
3. eliminate anticholinergic drugs
4. VMAT inhibitors
VMAT2 Inhibitors use
newer drug therapies for tardive dyskinesia
prevent dopamine from being packaged, decreasing dopamine release
Tetrabenazine
VMAT2 for Huntington’s chorea
Valbenazine
VMAT2 for tardive diskinesia
Deutetrabenazine
for tardive diskinesia and huntington’s chorea
Neuroleptic Malignant Syndrome
serious and rapid; 10% fatility
Symptoms of neuroleptic malignant syndrome
EPS symptoms with fever
Impaired cognition (agitation, delirium, coma)
muscle rigidity
Treatment of neuroleptic malignant syndrome
Restore dopamine balance
d/c drug
use DA agonists, diazepam, or dantrolene
Intractable Hiccupts
chlorpromazine
Alcohol withdrawal (hallucinations)
haloperidol
nausea and vomiting
metoclopramide
promethazine
potentiation of opiates and sedatives
droperidol
Behavioral effects of antipsychotic drugs
unpleasant in normal subjects or reversal of signs and symptoms of psychosis in affected individuals
neuroleptic syndrome of antipsychotic drugs
suppress emotions
reduce initiative and interest
affect
may resemble negative syndromes
Loss of accomodation, dry mouth, difficulty urinating, constipation
muscarinic cholinoceptor blockade
orthostatic hypotension, impotence, failure to ejaculate
alpha adrenoceptor blockade
PD, akathasia, dystonias
dopamine receptor blockade
tardive dyskinesia cause
supersensitivity of dopamine receptors
toxic-confusal state
muscarinic blockade
sedation
histamine receptor blockade
amenorrhea-galactorrhea, infertility, impotence
dopamine receptor blockade resulting in hyperprolactinemia
weight gain
possibly combined H1 and 5HT2c blockade
precautions and contraindications of antipsychotics
CV
PD
epilepsy (clozapine will lower seizure threshold)
diabetes (for newer agents)
Aliphathic Phenothiazines
chlorpromazine (no longer 1st line therapy)
Chlorpromazine Structure
R2: important for potency
R10: requires 3 atom chain (allows nitrogen to bind receptor)
2 atom chain = antihistamine
Aliphatic Phenothiazines used for H1 antagonist properties
promethazine
(also for N/V)
piperidine phenothiazines
thioridazine (sedation, hypotension, anticholinergic, many SE)
piperazine phenothiazines
fluphenazine (EPS)
prochlorperazine (antiemetic)
perphenazine (CATIE studies: combo with anticholinergic)
Thioxanthines
thiothixene: modest EPS
Butyrophenones
haloperidol (EPS)
strong D2 block
molindone
moderate EPS
pimozide
tourette’s disease
tics, vocalizaitons
Atypical/Second Gen Antipsychotics overview
more metabolic problems
reduced EPS
Clozapine
1st atypical antipsychotic
very effective
Agranulocytosis in Clozapine
occurs in 1-2% within 6 months
(weekly blood monitoring)
2nd or 3rd line therapy
Side Effects of Clozapine
anticholinergic, antihistamine
reduced D2 potency = decreased movement disorders
risk of diabetes
Olanzapine
- weight gain
- less likely to cause N/V
- less likely to cause movement disorders
- risk of diabetes
Loxapine
- older agent
- metabolite= amoxipine
- inhibits NET –> antidepressant
Quetiapine
- metabolite w/ antidepressant activity
- 5HT2a and D2
- low EPS
- low antimuscarinic
- hypotension (alpha 1)
- sedation (h2)
- risk of diabetes
Risperidone MOA
5HT2A and D3 receptor antagonist
Risperidone Pearls
relatively low EPS < 8 mg/day
weight gain, sedation
Paliperidone (Invega)
9-hydroxyrisperidone
Iloperidone
structurally related to risperidone
very potent at alpha 1 receptors
Ziprasidone MOA
5HT2A, D2, Alpha 1 affinity
Ziprasidone Pearls
prolongs QT interval
long acting formulation under study
Asenapine
5HT2A and D2
Lurasidone MOA
5HT2A and D2
Lurasidone Pearls
- less weight gain and metabolic effects
- fast onset (days without titration)
- low doses similar effectiveness to high doses
Pimavanserin
inverse agonist 5HT2A
PD psychosis
Aripiprazole MOA
high affinity for 5HT2 and D2
partial agonist at 5HT1A receptors (used in depression)
moderate affinity for D4, alpha, and histamine
Side Effects of Aripiprazole
weight gain
low risk for D2 effects
When is aripiprazole lauroxil given
q4-8 weeks
prodrug
Brexpiprazole MOA
D2/D3 partial agonist with less akathisia
Cariprazine MOA
D2/D3 partial agonist with greater affinity for D3
weak partial agonist activity at 5-HT1A
akathisia is high
Lumateperone MOA
partial D2 agonist presynaptic receptors/antagonists at postsynpatic receptors (5HT2A antagonist)
Key features that define psychotic disorders
delusions: fixed false beliefs that are not amendable to change even with confliction evidence
hallucinations
disorganized thinking and speech
disorgaanized or abnormal motor behavior
negative symptoms
Disease course in schizophrenia
onset late adolescence to early adulthood
men: late teens, early 20s
women: late 20s, early 30s
Smoking and Antipsychotics
smoking is associated with induction of 1A2 due to hydrocarbons produced and inhaled
decreases the serum concentration of 1A2 substrate antipsychotics (olanzapine, asenapine, clozapine, loxapine)
Which 3 medications can hasten the onset of schizophrenia, exacerbate symptoms, and reduce time to relapse
marijuana, cocaine, amphetamine
Must consider when prescribing antipsychotics
doses per day
side effects
previous drug therapy
cost of drug therapy
concomitant drug therapy
need for monitoring
First line for Schizophrenia
oral antipsychotic drug therapy is generally considered first-line, unless patient presents reasons to consider IM depot drug therapy first
Typical Antipsychotics MOA
D2 receptor antagonist
efficacy for positive symptoms is similar to atypical antipsychotics
Most commonly used typical antipsych
haloperidol: routine and prn
EPS in typical antipsych
more eps with higher potency
typical antipsych effect on positive, negative, cognitive symptoms
positive: effective
negative may worsen
cognitive: may worsen
Atypical Antipsychotics MOA
D2 antagonism + 5HT2A antagonist
Atypical EPS compared to Typical
less EPS, more metabolic side effects
Partial Agonists
stabilize dopamine transmission (not too much, not too little)
associated with more akathisia than other antipsychotics
approved for adjunct treatment of depression (have boxed warning for suicidal thoughts/behavior)
Aripiprazole MOA
partial agonist
Aripiprazole CYP P450
2D6 and 3A4 substrate
Aripiprazole akathisia
moderate
Aripiprazole weight gain
low
Brexpiprazole MOA
partial agonist
Brexpiprazole CYP P450
2D6 and 3A4 substrate
Brexpiprazole akathisia
moderate
Brexpiprazole weight gain
low-moderate weight gain
Cariprazine MOA
partial agonist
Cariprazine CYP P450
3A4 substrate
Cariprazine akathisia
moderate
Cariprazine weight gain
low-moderate
-Pines
less D2 antagonism, more 5HT2A antagonism
significantly less EPS
higher weight gain
Asenapine
sublingual and patch
QTc prolongation
Clozapine
boxed warnings for neutropenia, orthostaisis, bradycardia, syncope, seizures, myocarditis, cardiomyopathy
side effects: sedation, weight gain, constipation, hypersalivation, dry mouth, GI hypomotility with obstructive risk
QTc
Olanzapine
signficant weight gain and sedation
high risk metabolic syndrome
DRESS warning
1A2 Substrates
asenapine
clozapine
olanzapine
Quetiapine
3A4 substrate
QTc prolongation
weight gaine an sedation
boxed warning for suicidal ideation
Secuado (Asenapine) Patch Warning
QTc prolongation
Secuado (Asenapine) Patch Interactions
UGT and 1A2 substrate
reduce dose of patch if given with strong 1A2 inhibitor (fluvoxamine)
Clozapine REMS (ON EXAM)
monitoring timelines weekly x6months, biweekly x 6months, then every 4 weeks
Olanzapine/Samidorphan (Lybalvi)
Samidorphan is an opioid antagonist with preferential activity at the mu opioid receptor
the dones
D2 and 5HT2A antagonists
variable EPS and metabolic side effects
Iloperidone warning
high risk for othostasis and syncope
QTc prolongation
Iloperidone CYP interaction
2D6 substrate
Lurasidone CYP interaction
3A4 substrate
Lurasidone Warnings
suicidal thoughts
higher risk for akathisia
take with food to incrase bioavailability
Ziprasidone warnings
QTc prolongation (contraindication)
DRESS warning
take with food to increase absorption and bioavailabiltiy
Ziprasidone CYP interaction
3A4 and aldehyde oxidase
Risperidone and Paliperidone
highest D2 blockade for atypicals
highest EPS, moderate metabolic side effects
Risperidone CYP interaction
2D6 substrate (minor 3A4)
Risperidone SEs
EPS
hyperprolactinemia
weight gain
sedation
orthostatis
Paliperidone
renally eliminated
QTc prolongation
Lumateperone
low risk for weight gain or metabolic side effects
low risk for eps or akathisia
3A4 substrate
Pimavanserin
treatment of hallucinations or delusions in PD
inverse agonist and antagonist at the serotonin 5HT2A
3A4 inhibitor
Warnings for all Antipsychotics
- boxed warning for increased risk of death in elderly patients treated with antipsychotics for dementia with related behaviors
- metabolic adverse effects
- eps
- risk of somnolence, hypotension, increases risk for falls and fractures
Haloperidol Decanoate
given every 4 weeks
loading dose: 20x oral dose
maintenance: 10x oral dose
Risperdal Consta
must supplement with oral risperidone (or another oral antipsychotic) for the first few weeks of treatment (until 3rd injection)
Perseris (risperidone)
abdominal subq injection
34A inducers, use 120 mg dose or may need oral supplementation
Rykindo (risperidone)
every 2 week IM injection
oral dose overlap is shorter than risperdal Consta ( 7 days vs 21 days)
Uzedy (risperidone)
abdominal or upper arm subq injection
given once monthly or every 2 months
Invega Sustenna (paliperidone)
loading dose, then booster q4 weeks starting 5 weeks after loading injection
inital loading and booster must be given in deltoid
if loading, no need for oral overlap
may require dose adjustment in moderate to severe renal impairment
Invega Trinza (paliperidone)
may be initiated for a patient who has been on stable monthly (q4week) IM injection of Invega Sustenna at least four stable doses
recommended to be given in deltoid
not recommended if CrCl<50 mL/min
q3months
Invega Hafyera (paliperidone)
may be initiated after stable invega sustenna for 4 months or stable invega trniza after one 3 month dose
gluteal injection only
q6month
Zyprexa Relprevv (olanzapine)
PDSS - post dose delirium sedation syndrome
REMS
Abilify Maintena
must overlap with oral aripiprazole for at least 14 days after first injection
deltoid or gluteal
Dose Adjustments for P450 Interactiosn: Abilify Maintena
if taking 2D6 or 3A4 inhibitors or 3A4 inducers for more than 14 days as concomitant therapy
avoid 3A4 inducers use
Abilify Asimtufii (aripiprazole)
every 2 month dosing
gluteal injection only
continue oral aripiprazole for 2 weeks after first injection
Aristada (aripiprazole lauroxil)
overalap with oral aripiprazole for 3 weeks after first injection
Aristada Initio (aripiprazole lauroxil)
developed to avoid 21 day oral overlap of antipsychotic
avoid in patients who are 2D6 poor metabolizers or with strong 3A4 or 2D6 inhibitors
Commonly used immediate release antipsychotic injections
haloperidol, chlorpromazine, fluphenazine
Olanzapine IM and benzodiazepine IM
cannot be given at the same time, boxed warning for respiratory depression
Loxapine for inhalation
not commonly used for emergencies due to REMS
Treatment of Acutre Dystonia
IM anticholinergic now dose (benztropine 2 mg, diphenhydramine 50 mg)
Treatment of Drug Induced PD
oral anticholinergic
(trihexyphenidyl, diphenhydramien)
Treatment of Akathisia
beta blocker (propranolol)
benzodiazepine (lorazepam)
Treatment of Tardive Dyskinesia
VMAT inhibitors
Valbenzine CYP interacgtion
2D6/3A4 substrate
QTc prolongation
Duetetrabenazine CYP Interaction
2D6 substrate
QTc prolongation
Neuroleptic Malignant Syndrome
life threatening, medical emergency
hyperpyrexia, tachycardia, labile bp
muscle rigidity
treatment is suspportive
future antipsychotic use is not contraindicated
metabolic adverse effects
hyper glycemia, hyperlipidemia, hypertension
clozapine = olanzapine >
quetiapine = risperidone = paliperidone = asenapine = iloperidone = cariprazine = brexpiprazole >
ziprasidone = lurasidone = aripiprazone
personal family hx monitoring
baseline
yearly
weight (BMI) metabolic monitoring
baseline
4 weeks
8 weeks
12 weeks
every 3 months
waist circumference monitoring
baseline
yearly
BP/A1C monitoring
baseline
12 weeks
yearly
fasting lipids monitoring
baseline
12 weeks
every 5 years