Antipsychotic (Neuroleptic) Medications

Antipsychotic medications are used to treat 2 types of conditions:

• Schizophrenia and other psychotic disorders
• Hiccups, Tourette syndrome, and bipolar disorders

The mechanism of action is dopamine blockage at the postsynaptic receptors.

Table 10-1. Medication Side Effects

Side Effect	Peak	Treatment
Dystonic reaction	Hours to days	Anticholinergics: benztropine, trihexyphenidyl, diphenhydramine
Rigidity	3 weeks	Lower dose or anticholinergics
Tremors	6 weeks	Lower dose or anticholinergics
Akathisia	10 weeks	B-blockers, benzodiazepines; lower dose or switch to atypical
Tardive dyskinesia	>3–6 months	Switch to atypical or clozapine
Neuroleptic malignant syndrome	Any time	May be lethal; dantrolene or bromocriptine

Dopamine tracts include:

• Mesolimbic/mesocortical: reduces psychotic symptoms
• Nigrostriatal: increases movement disorder
• Tuberoinfundibular: increases prolactin (galactorrhea, amenorrhea, gynecomastia)

Note

Extrapyramidal reactions include:

• Choreiform: jerky movements
• Athetoid: slow, continuous movements
• Rhythmic: stereotypical movements

Types of Antipsychotics

Table 10-2. Typical vs. Atypical Antipsychotics

Typical	Atypical
Dopamine	Dopamine and serotonin
Treats mostly positive symptoms	Treats positive and negative symptoms
More side effects	Fewer side effects

The potency of typical antipsychotic medications is as follows:

Potency	Extrapyramidal Symptoms	Anticholinergic Effects
High (haloperidol)	High	Low
Low (chlorpromazine)	Low	High

Typical antipsychotics have movement and prolactin side effects.

• Haloperidol
• Fluphenazine
• Chlorpromazine
• Mesoridazine
• Thioridazine (additional increased risk of retinitis pigmentosa and retrograde ejaculation)

Atypical antipsychotics are known for weight gain, increased risk of diabetes, and metabolic syndrome, but also cause movement and prolactin side effects.

• Clozapine (additional increased risk of agranulocytosis (<1%), seizures, drooling)
• Risperidone
• Olanzapine
• Quetiapine
• Ziprasidone
• Aripiprazole (partial dopamine agonist)
• Paliperidone
• Lurasidone

Recall Question

1. A 26-year-old man comes to the psychiatrist for a follow-up appointment for his schizophrenia. He was recently started on a new medication. Today he complains of having difficulty with sexual intercourse and having brown-tinged vision. On which new antipsychotic medication was the patient recently started?
   

   1. Clozapine
   2. Haloperidol
   3. Thioridazine
      
   4. Quetiapine
   5. Ziprasidone

Answer: C