Antipsychotics Outline

Antipsychotics

Indications

  • Used for the treatment of schizophrenia and other psychotic disorders; selected agents are also used in the treatment of bipolar mania, as antiemetic, in the treatment of intractable hiccoughs, and for control of tics and vocal utterances in Tourette’s disorder.

Typical antipsychotics

  • Block postsynaptic dopamine receptors in the basal ganglia, hypothalamus, limbic system, brainstem, and medulla.
  • Demonstrate varying affinity for cholinergic, alpha-1-adrenergic, and histaminic receptors.
  • Inhibit dopamine-mediated transmission of neural impulses at the synapses.

Atypical antipsychotics

  • Weaker dopamine receptor antagonists than the typical antipsychotics
  • Potent antagonists of the serotonin type 2A (5H T-2A) receptors
  • Exhibit antagonism for cholinergic, histaminic, and adrenergic receptors
  • Contraindicated in hypersensitive, comatose, or severely depressed patients; elderly patients with dementia-related psychosis; certain medications are contraindicated in patients with a history of Q T prolongation or other heart issues.
  • Caution with elderly or debilitated patients; patients with cardiac, hepatic, or renal insufficiency; those with a history of seizures; patients with diabetes or risk factors for diabetes; clients exposed to temperature extremes under conditions that cause hypotension; and pregnant clients or children

Drug interactions

Interacting Drugs

Adverse effects

Antihypertensives, CNS depressants, Epinephrine or dopamine in combination with haloperidol or phenothiazine

Additive and potentially severe hypotension

Oral anticoagulants with phenothiazine

Less effective anticoagulant effects

Drugs that prolong Q T intervals

Additive effects

Drugs that trigger orthostatic hypotension

Additive hypotension

Drugs with anticholinergic effects, prescription and over-the-counter drugs

Additive anticholinergic effects including anticholinergic toxicity, which includes flushing, hypertension, dry mouth, mydriasis, urinary retention, altered mental status, tachycardia, and tremelousness

Nursing diagnosis

  • Risk for other-directed violence
  • Risk for injury
  • Risk for activity intolerance
  • Noncompliance

Drug Classification

Drug trade/ Generic names

Actions

Side effects

Nursing implication

First-Generation (Conventional or typical)

Thorazine (Chlorpromazine)

Mellaril (thioridazine)

Loxitane (loxipine)

Moban (Molindone)

Trilafon (Perphenazine

Trifluoperazine

Navane (Thiorthixene)

Prolixin (Fluphenazine)

Haldol (Haloperidol)

Orap (Pimozide)

Strong antagonist to Dopamine receptors, blocking the action of dopamine.  Antagonist to muscarinic receptors for acetylcholine, adrenergic receptors for norepinephrine and histamine receptors.

Extrapyramidal symptoms (EPS) such as acute dystonia, akathisia, dyskinesia, tardive dyskinesia, and pseudoparkinsonism.  In women, amenorrhea, and in men, gynecomastia. Anticholinergic side effects, low seizure threshold, tachycardia, hypotension, and ejaculatory dysfunction.

Perform AIMS test with conventional antipsychotics.  Monitor for signs of dry mouth, sedation, blurred vision, and dry mouth.  Monitor vital signs

Second-Generation

(Atypical)

Clozaril (Clozapine)

Zyprexa (Olanzapine)

Invega (Paliperidone)

Seroquel (Quetiapine)

Risperdal (Risperidone)

Geodon (Ziprasidone)

Dopamine and serotonin antagonists (blockers).  Thought to decrease psychosis.

Weight gain, insulin resistance, metabolic syndrome, sexual dysfunction.

Clozaril – 1st atypical antipsychotic to be used. Frequent monitoring of WBCs every 1-2 weeks due to bone marrow suppression and agranulocytosis.

Risperdal – high risk for EPS.  Monitor weight.

Issues in Antipsychotic Maintenance Therapy

  • Clozapine (Clozaril) and Agranulocytosis risk
    • Medications such as clozaril have risks of agranulocytosis (blood disorder in which the patient’s absolute neutrophil count (ANC) drops to extremely low levels) causing neutropenia
  • Extrapyramidal side effects
    • Pseudoparkinsonism, Akinesia (Impairment in voluntary movement), Akathisia (continuous restlessness), Dystonia (Involuntary muscle spasms), Oculogyric crisis (uncontrolled rolling back of the eyes), and Tardive dyskinesia (unusual facial and tongue movements, stiff neck, and difficulty swallowing)
  • Hormonal side effects
    • In men: Decreased libido, gynecomastia, retrograde ejaculation,
    • In women: Amenorrhea galactorrhea