The document summarizes key information about antipsychotic medications, including: - There are two classes of antipsychotics: typical/conventional which block dopamine receptors and atypical/novel which block serotonin and dopamine receptors. - Typical antipsychotics are further divided into low, mid, and high potency. High potency antipsychotics like haloperidol have the least sedation and anticholinergic side effects but highest risk of EPS. - Atypical antipsychotics like clozapine, risperidone, and olanzapine tend not to cause EPS but can increase risks of weight gain, diabetes, and other side effects. Clozapine specifically requires regular blood

1. Rohin Khanna

2.  2 Classes of antipsychotics
 Typical / Conventional
▪ Block Dopamine D2 receptors
▪ Work on +ve symptoms (hallucinations/delusions)
 Atypical / Novel
▪ Block serotonin and dopamine receptors
▪ Also M3 (olanzapine), H1 (quetiapine), α, D4 (clozapine)
▪ Work on +ve and –ve symptoms (blunted affect, poverty
of speech, anhedonia)

3.  Conventional/Typical  Usual Dose, PO/D, mg
 Low Potency
▪ Chlorpromazine (Thorazine) ▪ 100-1000 (IM)
▪ Thioridazine (Mellaril) ▪ 100-800
 Mid Potency
▪ Trifluoperazine (Stelazine) ▪ 2-15
▪ Perphenazine (Trilafon) ▪ 4-32
 High Potency
▪ Haloperidol (Haldol) ▪ 0.5-10 (IM)
▪ Fluphenazine (Prolixin) ▪ 1-10 (IM)
▪ Thiothixene (Navane) ▪ 2-20

4.  High Potency
 Least sedating
 Have no anticholinergic symptoms (dry
mouth, constipation, hot, dry skin, tachycardia, delirium in
elderly)
 High tendency for EPS
 Low Potency
 Most sedating
 Have more anticholinergic symptoms
 Lower tendency for EPS
 Mid Potency
 Well tolerated

5.  Novel /Atypical  Usual Dose, PO/D, mg
 Clozapine (Clozaril)  200-600
 Risperidone (Risperdal)  2-6
 Olanzapine (Zyprexa)  10-20 (IM)
 Quietapine (Seraquel)  300-400
 Aripiprazole (Abilify)  10-30 (IM)
 Ziprasidone (Geodon)  20-80 (IM)

6.  Tend not to induce EPS
 Weight gain, induce onset DM (exp clozapine,
olanzapine)
 Other SE, drooling, sedation, amenorrhea
 Clozapine may cause agranulocytosis
 WBC/ANC baseline
 qWk 6 months, q2wk 6 months, q4wk > 1 year
 Continue for qwk 1 month after d/c

7.  EPS
 Begin several hours to weeks of start treatment
 Include acute dystonia (muscle spasm, stiffness), akinesia
(parkinsonian-like, decreased movements), akathisia
(restlessness, increased movements), tardive dyskinesia
(facial, distal extremities involuntary movements)
 NMS
 Hyperpyrexia, muscle rigidity, agitation, increased
WBC/CK/myoglobinuria
 Tx= supportive, dantrolene (muscle relaxant, binds
ryanodine rec, dec Ca2+), bromocriptine (dopamine
agonist)

8.  Braunwald, E., et al. (2002). Harrison’s manual of medicine.
International Edition: McGraw Hill.
 Bhushan, V., Le, T. (2011). First Aid for the USMLE Step 1
2011: A Student to student guide. McGraw Hill.
 Jann MW, Grimsley SR, Gray EC, Chang WH.
Pharmacokinetics and pharmacodynamics of clozapine. Clin
Pharmacokinet 1993; 24:161.