Antipsychotic Drugs Flashcards
Describe the Dopamine Hypothesis of Psychotic Disease:
Evidence supporting? Evidence against?
Abnormal DA transmission within the mesolimbic and mesocortical pathways cause psychosis sx.
Support: Antipsychotics block D2 receptors and improve sx.
Against: Antipsychotics take pharm effect immediately, but psychosis takes time to disappear (synaptic remodeling)
How is the nigrostriatal DA pathway implicated in the treatment of psychosis?
Extrapyramidal (parkinson like syndrome) effects due to drugs that block DA receptors in this tract
Describe the changes in mesolimbic DA associated with psychosis:
What kind of sx do they cause?
How are they treated?
Elevated DA signaling/ neuronal activity
Hyperactive/ positive sx.
Tx: Neuroleptics/Typical antipsychotics
Describe the changes in mesocortical DA associated with psychosis:
What kind of sx do they cause?
How are they treated?
- Decreased DA signaling/ neuronal activity
- Hypoactive/ negative sx.
- Tx: Atypical antipsychotics > Neuroleptics/ Typicals
- Negative sx are harder to treat than positive sx.
What kind of hallucinations are associated with drug abuse/ withdrawal?
Visual
What kind of hallucinations are associated with innate psychosis?
Auditory
List three toxic agents that can cause psychosis
- Heavy metals (Hg)
- Digitalis
- L-Dopa
List 5 metabolic syndromes that can cause psychosis
- Hypoglycemia
- Acute intermittent porphyria
- Cushings***
- hypo/hyper Ca++
- hypo/hyperthyroid
List 3 nutritional deficiencies that can cause psychosis
- Thiamine
- Niacin
- B12
(All of the Bs)
List 4 neurological illnesses that can cause psychosis
- stroke
- tumor (brain)
- neurodegenerative disease
- hypoxic encephalopathy
List 6 Examples of positive psychotic sx.
- Agitation
- Delusion
- Hallucination
- Disorganized speech
- Disorganized thought
- Insomnia
(Addition of a quality that was not originally there/ altertness, increased activity)
List 6 Examples of negative psychotic sx.
- Apathy
- Flat Affect
- Lack of motivation
- Lack of pleasure
- Poverty of speech
- Social isolation
How does treatment of psychosis differ in an inpatient vs. outpatient setting? What are the goals like in each situation?
- Inpatient–treat active psychosis, get patient home/ prevent violence
- Outpatient–prevent relapse, maintain social adjustment
What is the MOA for ALL Antipsychotic Drugs?
How does this differ between typicals and atypicals?
Competitive block–> DA + 5HT Receptors
Typicals: Affinity D2 > 5HT2
Atypical: Affinity 5HT2 >D2
Which part of the DA pway is primarily targeted by the atypicals?
How is this possible?
Which patients are these drugs exceptionally good for?
Do they treat + or - sx?
Mesolimbic > Nigrostriatal
- 5HT2 regulates release of DA in mesolimbic away
- Atypicals are more selective for 5HT2R’s
Good for drug refractory pts
Treat + and - sx.
Where are antipsychotics metabolized? Excreted?
Met: liver, active and inactive metabolites
Excreted: Renal, glucuronide conjugates
What is the half life like for antipsychotic drugs?
Broad range: 20-40hrs.
How are antipsychotic drugs absorbed? excreted?
Erratically in GI tract; renally excreted
What are three effects of D2 blockade that initially activate pre-synaptic D2 receptors?
- ^ DA synth and release
- ^ cAMP
- LOWER K+ currents
* Will eventually be reversed
Describe the short and long term effects of antipsychotics at the D2 pre-synaptic cleft
short term: activate neurons
long term: inactivate neurons
Describe the short and long term effects of antipsychotics at the D2 post-synaptic cleft
short term: receptor blockade
long term: receptor hypersensitivity (due to low DA levels)
Describe the symptomatic changes with 1-3 days of antipsychotic treatment (4)
- Decrease agitation/hostility
- Decrease combativeness/ aggression
- Decrease anxiety
- Normalization of eating and sleeping patterns
Describe the symptomatic changes with 1-2 weeks of antipsychotic treatment (3)
- Increase socialization
- Improve self care
- Improve mood
Describe the symptomatic changes with 3-6weeks of antipsychotic treatment
- Improve disorders thought
- Decrease delusion and hallucination
- Patients can have appropriate conversation and participate in psychotherapy***
How long does it typically take the for antipsychotics to alleviate positive sx. ?
1-3 weeks
Haloperidol:
Drug Class
Therapeutic uses (3)
Notable ADRs
Typical Antipsychotic–Butyrophenone
Tx: Psychosis, Gilles de la Tourette’s, Huntington’s
ADRs: Severe extrapyramidal effects
Chlorpromazine: Drug Class Therapeutic uses (2) ADRs (2) CI
Typical Antipsychotic–Phenothiazine (prototype)
Tx: Psychosis, intractable hiccups
ADRs: *Fewer extrapyramidal effects due to simultaneous anticholinergic effects (maintain balance), deposits in lens and cornea
CIs: seizure disorders (lowers threshold)
All antipsychotics with the exception of these two can be used as antiemetics
- aripiprazole
2. thioridazine
Why are antipsychotics effective antiemetics?
Block D2 at in the area postrema CTZ–do not need to cross BBB
Prochlorperazine
MOA
Therapeutic Use
Broad drug class
Treatment of nausea asstd with chemotherapy
(blocks D2Rs in CTZ)
Typical
Scopolamine
MOA
Therapeutic Use
Treatment of motion sickness (blocks D2Rs in CTZ)
Antagonism of 5 receptor types causing ADRs to antipsychotics
- Muscarinic
- Alpha Adrenergics (esp A1)
- D2 (excess)
- 5HT (excess)
- H1
- Drugs affect different receptors in different proportions
- Choose drug based on pt needs
3 Extrapyramidal Effects of Antipsychotic Drugs
Which Drugs are worst for this?
How do we treat the ADR?
- Restless/Akathisia
- Pseudoparkinsonism
- Dystonia/ Facial grimace
WORST in D2 Specifics:
Haloperidol***
Fluphenazine
Thiothixene
Tx: Withdraw neuroleptic + Admin centrally active anticholinergic–> start on atypical or drug with more anticholinergic effects when clear
Which drugs cause the least extrapyramidal effects?
Atypical antipsychotics + typicals with more anticholinergic effects (Thioridazine, Chlorpromazine)
What is tardive dyskinesia and how does it develop?
Which antipsychotics are the worst for this?
How is it treated?
Mos/ yrs of antipsychotic tx–> abnormal facial and oral movements due to hypersensitivity of DA receptors
WORST: Typicals
Tx: None for advanced cases, must be recognized early, may worsen with withdrawal
Which drug has a low incidence of tardive dyskinesia?
Clozapine (Atypical)
Neuroleptic Malignant Syndrome:
Describe disease
Which drug class causes this ADR?
How is it treated?
Like malignant hyperpyrexia
WORST: Typicals
TX: Bromocriptine, Dantrolene–> Switch to atypical upon recovery
How do antipsychotics elevate prolactin? What kind of side effects may this cause, and why is this a problem? Which drug class is exceptionally bad for this ADR?
-Inhibition of D2R’s in Tubuloinfundibular Pway
-Menstrual irregularity/Low libido/Galactorrhea/osteoperosis
POOR COMPLIANCE
-WORST: Phenothiazines
- What are the effects of cholinergic blockade by antipsychotic drugs?
- Which drugs cause these effects? (4)
- How are these ADRs managed?
Opposite of SLUDE BBB;
- Thioridazine
- Chlorpromazine
- Olanzapine
- Clozapine (except increases salivation*)
- Change to drug with lower M1 activity
Which antipsychotics have a lot of A-Adrenergic activity? (2)
Which patient populations should avoid treatment with these drugs?
- Chlorpromazine
- Mesoridazine
CI: CVD, HTN (due to ^TPR, BP, Cardiac vasocnstrxn)
Describe three metabolic side effects of antipsychotic drugs
- New onset/ exacerbation of DM II
- HTN
- Hyperlipidemia
Clozapine, Olanzapine
Relative weight gain, lipids, glucose effects
Weight gain ++++
Lipids +++
Glucose +++
Chlorpromazine
Relative weight gain, lipids, glucose effects
Weight gain +++
Lipids +++
Glucose ++
Risperidone
Relative weight gain, lipids, glucose effects
Weight gain +
Lipids +/-
Glucose +/-
Haloperidol
Relative weight gain, lipids, glucose effects
Weight gain +/-
Lipids -
Glucose -
What are important monitoring tests to be done on patients taking antipsychotics? (3)
- BMI/ waist circ.
- Serum lipids
- Fasting glucose or A1C
Which antipsychotic causes a Leukopenia and Agranulocytosis?
Clozapine (1-2% pts)
Describe “Perioral Rabbit Syndrome”
How is it treated
Perioral tremors caused by years of antipsychotic use
Treat with anticholinergic antiparkinson drugs
Which two antipsychotic drugs have cardiac effects?
What are the effects they cause?
Typical or atypical?
Thioridazine: minor T wave abnormalities (OD = ventricular arrhythmia); typical
Ziprasidone: QT prolongation; Atypical
WHICH PATIENT POPULATION NEVER GETS ANTIPSYCHOTICS?
PREGGOS/ BREASTFEEDING
What is one very important comorbid drug of abuse in psychotic patients? Why is it important?
Cigarettes/ nicotine–alter CYP activity
Can cause overdose or ineffectiveness of prescribed antipsychotic
List 5 drugs that should not be taken in tandem with antipsychotics
- Central depressants–> DEATH
- Amphetamines–> negate effects
- Centrally acting anticholinergics–> worsen tardive dys.
- SSRI–> serotonin storm
- Antihypertensives–> excessive HypoTN
Phenothiazines: Typical or Atypical? How to identify them Important drug in this class Important ADR assc with this entire class
Typical
All end in “azine”
*Chlorpromazine
Prolactin secretion
Thioxanthenes:
Typical or Atypical?
How to Identify them
Typical
All end in “ene”
Haloperidol, Spiperone- broad drug class
atypical vs typical
Typical
Typical antipsychotic in the Azepine drug class
Loxapine
Molindone- broad drug class
Typical
Two important Atypical Azepines
Clozapine
Olanzapine
Common ending for all Azepines
*All drugs in this class end in “ine”, whether
Risperidone- broad drug class
Atypical antipsychotic
Ziprasidone- typical or atypical?
Atypical
Most anti-psychotics have what effect on the circulatory system?
hypotension; perpetuate the effect of anti-hypertensive agents
Both cocaine and amphetamines may mimic?
Psychosis
Cocaine/ amphetamine MOA
Cocaine- blocks DA/NE reuptake
Amphetamine- ^DA
Anti-cholinergics commonly used to reduce extra-pyramidal sx assc with anti-psychotics
Trihexylphenidine Benztropine (1936 mercedes benz) BIperidine ProCYCladine (bicycle)
MOA and use for Bromocriptine
D2 agonist
reverses neuroleptic syndrome along with dantrolene
In addition to D2 and 5HT2 block, what are the three other receptors that are blocked by anti-psychotics and responsible for many ADRs?
H1, a1/2, m
Mesoridazine- broad class; 1 assc ADR
typical; a adrenergic activity (hypotension)
Chloropromazine has a TON of ADRs/CI; List (6):
prolactin weight gain/metabolic syndrome anti-muscarinic anti-histamine anti-adrengeric CI in seizures
Ariprazole- broad class and one fact that distinguishes is from other anti-psychotics?
atypical; cannot be used as an anti-emetic