Antipsychotics

Pharmacologic Profile

General Use

Treatment of acute and chronic psychoses, particularly when accompanied by ↑ psychomotor activity. Use of clozapine is limited to schizophrenia unresponsive to conventional therapy. Selected agents are also used as antihistamines or antiemetics. Chlorpromazine is also used in the treatment of intractable hiccups.

General Action and Information

Block dopamine receptors in the brain; also alter dopamine release and turnover. Peripheral effects include anticholinergic properties and alpha-adrenergic blockade. Typical antipsychotics include the phenothiazines and haloperidol. Atypical antipsychotics may have fewer adverse reactions compared to the typical antipsychotics and include aripiprazole, asenapine, brexpiprazole, cariprazine, clozapine, iloperidone, lurasidone, paliperidone, olanzapine, paliperidone, pimavanserin, quetiapine, risperidone, and ziprasidone. Phenothiazines differ in their ability to produce sedation (greatest with chlorpromazine and thioridazine), extrapyramidal reactions (greatest with prochlorperazine and trifluoperazine), and anticholinergic effects (greatest with chlorpromazine).

Contraindications

Hypersensitivity. Cross-sensitivity may exist among phenothiazines. Should not be used in angle-closure glaucoma. Should not be used in patients who have CNS depression.

Precautions

Safety in pregnancy and lactation not established. Use cautiously in patients with symptomatic cardiac disease. Avoid exposure to extremes in temperature. Use cautiously in severely ill or debilitated patients and patients with respiratory insufficiency, diabetes, prostatic hypertrophy, or intestinal obstruction. May ↓ seizure threshold. Clozapine may cause agranulocytosis. Most agents are capable of causing neuroleptic malignant syndrome. Should not be used routinely for anxiety or agitation not related to psychoses.

Interactions

Additive hypotension with acute ingestion of alcohol, antihypertensives, or nitrates. Antacids may ↓ absorption. Phenobarbital may ↑ metabolism and ↓ effectiveness. Additive CNS depression with other CNS depressants, including alcohol, antihistamines, antidepressants, opioid analgesics, or sedative/hypnotics. Lithium may ↓ blood levels and effectiveness of phenothiazines. May ↓ the therapeutic response to levodopa. May ↑ the risk of agranulocytosis with antithyroid agents.

Nursing Implications

Assessment

Assess patient's mental status (orientation, mood, behavior) before and periodically throughout therapy.
Monitor BP (sitting, standing, lying), pulse, and respiratory rate before and frequently during the period of dosage adjustment.
Observe patient carefully when administering medication to ensure medication is actually taken and not hoarded.
Monitor patient for onset of akathisia—restlessness or desire to keep moving—and extrapyramidal side effects; parkinsonian effects—difficulty speaking or swallowing, loss of balance control, pill rolling, mask-like face, shuffling gait, rigidity, tremors; and dystonia—muscle spasms, twisting motions, twitching, inability to move eyes, weakness of arms or legs—every 2 mo during therapy and 8–12 wk after therapy has been discontinued. Parkinsonian effects are more common in geriatric patients and dystonias are more common in younger patients. Notify health care professional if these symptoms occur, as ↓ in dosage or discontinuation of medication may be necessary. Trihexyphenidyl, benztropine, or diphenhydramine may be used to control these symptoms.
Monitor for tardive dyskinesia—uncontrolled rhythmic movement of mouth, face, and extremities; lip smacking or puckering; puffing of cheeks; uncontrolled chewing; rapid or worm-like movements of tongue. Notify health care professional immediately if these symptoms occur; these side effects may be irreversible.
Monitor for development of neuroleptic malignant syndrome—fever, respiratory distress, tachycardia, convulsions, diaphoresis, hypertension or hypotension, pallor, tiredness, severe muscle stiffness, loss of bladder control. Notify health care professional immediately if these symptoms occur.

Potential Nursing Diagnoses

Disturbed thought process (Indications)
Deficient knowledge related to disease processes and medication regimen (Patient/Family Teaching)
Noncompliance (Patient/Family Teaching)

Implementation

Keep patient recumbent for at least 30 min following parenteral administration to minimize hypotensive effects.
Administer with food, milk, or a full glass of water to minimize gastric irritation.
Dilute most concentrates in 120 mL of distilled or acidified tap water or fruit juice just before administration.

Patient/Family Teaching

Advise patient to take medication exactly as directed and not to skip doses or double up on missed doses. Abrupt withdrawal may lead to gastritis, nausea, vomiting, dizziness, headache, tachycardia, and insomnia.
Advise patient to make position changes slowly to minimize orthostatic hypotension.
Medication may cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to the medication is known.
Caution patient to avoid taking alcohol or other CNS depressants concurrently with this medication.
Advise patient to use sunscreen and protective clothing when exposed to the sun to prevent photosensitivity reactions. Extremes of temperature should also be avoided, as these drugs impair body temperature regulation.
Advise patient that ↑ activity, bulk, and fluids in the diet helps minimize the constipating effects of this medication.
Instruct patient to use frequent mouth rinses, good oral hygiene, and sugarless gum or candy to minimize dry mouth.
Advise patient to notify health care professional of medication regimen before treatment or surgery.
Emphasize the importance of routine follow-up exams and continued participation in psychotherapy as indicated.

Evaluation/Desired Outcomes