Schizophrenia Drugs

Question 1

Conventional/Typical Antipsychotics

Answer 1

Chlorpromazine (Thorazine, Largactil) - low potency
Loxapine (Loxapac) - medium potency
Haloperidol (Haldol), Fluphenazine (Modecate) - high potency

Drug Mechanism of Action

Dopamine antagonists – block D2 dopamine receptor sites

Therapeutic Action: Target positive symptoms of Schizophrenia

Advantage: Less expensive

Disadvantage

• Do not treat negative symptoms
• Extrapyramidal side effects EPSs
• Anticholinergic side efects

Adverse Effects

• Hypotension
• Lowered seizure threshold
• Weight gain
• Sexual dysfunction in males
• Galactorrhea
• Menstrual irregularities

Question 2

Atypical Antipsychotics/Second Generation

Answer 2

1. risperidone (Risperdal); Risperdal Consta (long acting injectable) now available
2. olanzapine (Zyprexa)
3. quetiapine (Seroquel)
4. clozapine (Clozaril) - carries the risk of agranulocytosis (↓WBC)

Drug Mechanism of Action

Serotonin-dopamine antagonists – blocks dopamine and serotonin receptors

Therapeutic Action: Treat both positive and negative symptoms

Advantage: Minimal to no EPS side effects or tardive dyskinesia

Disadvantage

Metabolic Sydrome

• Weight gain
• Dyslipidemia
• Altered glucose metabolism
• Increase risk of diabetes
• Cardiovascular disease

Question 3

Atypical Antipsychotics – Third Generation

Answer 3

aripiprazole (Abilify)

· Treats both positive and negative symptoms
· Also used for mania and an adjunct treatment for major depression
· Most common side effects - anxiety, headache, insomnia, lightheadedness, restlessness, nausea, vomiting, constipation, weight gain

Question 4

Potentially Dangerous Responses to Antipsychotics

Answer 4

Neuroleptic malignant syndrome (NMS) - rare (.02%-1%).

Symptoms include reduced level of consciousness, muscle rigidity, fever, hypertension, tachycardia, tachypnea, diaphoresis, and drooling

Agranulocytosis - low white blood cell count. It is a serious side effect and can be fatal. Blood work is usually done every week for 6 months, then every 2 months.

Liver impairment may also occur. Liver function test should be done every 6 months

Question 5

Adjuncts to Antipsychotic Drug Therapy

Answer 5

· Antidepressants

• *Anticonvulsants (mood stabilizers**) - i.e. lamotrigine (Lamictal), carbamazepine (Tegretol), valproic acid (Depakene), Topiramate (Topamax), divalproex sodium (Epival)
• *Benzodiazepines - to reduce agitation i**.e. clonazepam (Rivotril), diazepam (Valium), lorazepam (Ativan)