Pharm Test 3 Antipsychotics

Question 1

CLOZAPINE
Risperidone
Paliperidone
Olanzapine
Quetiapine
Ziprasidone
Aripiprazole

Answer 1

AtypicalAntipsychotics

Dual antagonsim: 5HT2A + D2. More effective at treating -ve sxs

Less likely to cause EPRs especially Clozapine and quetiapine

Paliperidone is the active metabolite of risperidone.

Aripiprazole: partial agonist at D2 and 5HT1, 5HT2 antagonist

MOA: Higher affinity for other receptors than D2

• ->Closapine: D1, D4, 5HT2, M and alpha adreneric
• ->Risperidone 5HT2

Question 2

AE of Antipsychotics

Answer 2

Parkinsonism: Tx: benztropine, trihexyphenidyl, amantadine, or diphenhydramine. NEVER use Levodopa in these pts
Akathisia: inability to sit still. Tx: decrease dose or change drug: Clonazepam or propranolol may also be added
Acute Dystonia: Tx: same as parkinsonism
TardiveDyskinesia: Choreoathetosis (usually see in the mouth). may be irreversible (due to DA receptor upregulation with chronic use) Tx: discontinue or decrease dose of drug. Eliminate all central anticholinergics (TCA); diazepam may be helpful
Neuroleptic Malignant Syndrome: Muscle rigidity, fever, AMS, Stupor, myoglobinemia and unstable BP. Tx: dantrolene or bromocriptine
Sedation: due to central H1 block
Seizures: Chlorpromazine, Clozapine
Orthostatic hTN and impaired ejaculation (alpha1 blockade)
**Agranulocytosis: Due to clozapine (RBC counts are mandatory)
Prolactinemia: less likely with atypicals
Weight Gain: (clozapine, olanzapine; not ziprasidone) –> Type 2 DM, HTN, increase hyperlipidemia
Cardiotoxicity: Thioridazine causes V tach; Ziprasidone prolongs QT
Ocular: Chlorpromazine –>corneal and lens deposits; Thioridazine –>retina

Question 3

Other useful facts about Antipsychotics

Answer 3

Uses: Schizophrenia, Tourettes, huntingtons, Alzheimers dementia.
Non psychiatric uses: nausea/vomiting
- Risperidone=most prescribed antipsychotic in the US
-Clozapine is reserved for cases due to potential for agranulocytosis
-Clozapine is pregnancy cat. B. Everything else is C.
Atypicals have a greater risk of hyperglycemia and weight gain in pregnancy

Question 4

Positive psychotic Sxs linked to…

Answer 4

Overactivity of dopamine neurons in the mesolimbic dopamine pathway (also in nigrostriatal, mesocortical and tuberoinfundibular)

Question 5

Dopamine hypothesis

Answer 5

Drugs that increase DA activity will produce +ve psychotic sxs while drugs that decrease DA activity will decrease or stop the +ve sxs

• ->Amphetamine and cocaine can cause a paranoid psychosis that is indistinguishable from schizophrenia
• -> Antipsychotics are D2 blockers; the mesocortical pathway may be involved in -ve sxs (blocking D2 receptors in this pathway will worsen the -ve and cognitive sxs of psychosis)

Question 6

Fluphenazine
Thiothixene
Haloperidol

Chlorpromazine
Thioridazine

Answer 6

Classical Antipsychotics

High potency: F,T,H -> more liely to produce EPRs
Low potency: C,T -> more likely to produce sedation and postural hypotension

MOA: Efficacy correlates with ability to block D2 in the mesolimbic pathway

Question 7

Actions of antipsychotics

Answer 7

• Antipsychotic
• Antiemetic by blocking D2 in the chemoreceptor trigger zone of the medulla (except: Thioridazine and aripiprazole)
• Decrease hallucinations and agitation, calming effect
• Do not depress intellectual fxn, minimal motor incoordination
• Action begins in