Drugs Used for Psychoses

Psychosis

• Clinical descriptor, not exact definition.

• Characteristics:

  • Out of touch with reality.

  • Perceptual deficits (hallucinations, delusions).

  • Deterioration in social functioning.

• Symptoms can be associated with illnesses like dementia, mood disorders; can be drug-induced.

• Schizophrenia is the most common psychotic disorder; influenced by biologic, psychosocial, and environmental factors.

Symptoms of Psychosis

• Delusions

• Hallucinations

• Disorganized thinking (loosening of associations)

• Disorganized behavior

• Negative symptoms (changes in affect)

Treatment of Psychosis

• Decrease symptoms that interfere with functioning.

• Target symptoms are critical monitoring parameters.

• Drug and nondrug therapies.

• Determine baseline level of functioning.

• Define treatment goals in terms of decreasing severity of target symptoms.

Drug Therapy for Psychosis

• Antipsychotic (neuroleptic) agents classified as:

  • Phenothiazines and nonphenothiazines

  • Low potency and high potency: Refers to the milligram dose

  • Typical or atypical: Refers to first- and second-generation agents

Antipsychotic Agents

• Actions

  • Typical agents: Block action of dopamine in the brain

  • Atypical agents: Block serotonin receptors in addition to dopamine receptors

• Use: Treat psychoses associated with mental illnesses (schizophrenia, mania, psychotic depression, psychotic organic brain syndrome)

• Types

  • Typical (examples): Phenothiazines, Non-phenothiazines, Thioxanthenes ( chlorpromazine , haloperidol , droperidol)

  • Atypical (examples): Aripiprazole (Abilify), Olanzapine (Zyprexa), clozapine , Risperidone (Risperdal) – block dopamine and serotonin receptors; they are more effective and have fewer adverse effects than typical agents.

Adverse Effects of Antipsychotic Agents

• Extrapyramidal symptoms: Four types

  • Dystonic reactions/acute dystonia (spasmodic movements)

  • Pseudoparkinsonism (tremor, muscular rigidity, masklike expression, shuffling gait, loss/weakness of motor function)

  • Akathisia (pacing, rocking, subjective feelings of anxiety and restlessness)

  • Tardive dyskinesia (hyperkinetic abnormal movements)

  • Extrapyramidal symptoms are the most common causes of antipsychotic therapy noncompliance

• Neuroleptic malignant syndrome

  • High fever, sweating, unstable BP

  • Can be fatal

• Seizures

• Weight gain

• Hyperglycemia

• Dyslipidemia

• Dysrhythmias

Other Adverse Effects

• Receptor-blocking activity:

  • Blocking cholinergic: anticholinergic effects (e.g., dry mouth, constipation, blurred vision).

  • Blocking histamine-1 receptors: sedation, drowsiness, appetite stimulation, hypotensive effects, potentiation of CNS depressant drugs

• Receptor blocking agents (antagonists): Drugs that interfere with the natural function of receptor

• Agonist: substance which initiates a physiological response when combined with a receptor

Nursing Assessment

• History of behavior

• Basic mental status

• Interpersonal relationships

• Mood/affect

• Clarity of thoughts/perception

• Suicidal ideation

• Psychomotor function

• Sleep pattern

• Dietary history

Implementation

• Safe, structured environment

• Acceptance, encourage expression of feelings

• Encourage self-care activities

• Use kind, firm manner to handle inappropriate behaviors

• Be open and direct with suspicious patients

• High-protein, high-calorie foods for patients who are active, pace

Patient Education

• Orient individual to unit (if applicable)

• Base patient education on assessment data

• Foster health maintenance

• Involve patient and family

• Use baseline clinical evaluation rating scales

• Use adverse effect scales for dystonias

Drug Class: Antipsychotic Agents

• Action: Block action of dopamine in the brain

• Use: Treat psychoses associated with mental illnesses (schizophrenia, mania, psychotic depression, psychotic organic brain syndrome)

• Therapeutic outcome: Maintaining individual at optimal level of functioning, with minimal exacerbations of psychotic symptoms and minimal adverse effects from medicines

Premedication Assessment

• Blood pressure in supine, sitting, and standing positions

• Electrolytes

• Hepatic function

• Renal function

• Cardiac function

• Thyroid function

• Baseline clinical evaluation rating scales and adverse effect scales

Common Adverse Effects

• Neurologic (chronic fatigue; drowsiness)

• Cardiovascular (orthostatic hypotension)

• Sensory (blurred vision)

• Genitourinary (urinary retention)

• Gastrointestinal (constipation; dryness of mucosa of mouth, throat, and nose)

Serious Adverse Effects

• Neurologic (seizure activity, pseudoparkinsonian symptoms, tardive dyskinesia)

• Gastrointestinal (hepatotoxicity)

• Hematologic (blood dyscrasias)

• Hypersensitivity (hives, pruritus, rash)

• Photosensitivity

Drug Interactions

• Increase adverse effects:

  • Antihistamines

  • Alcohol

  • Analgesics

• Decrease therapeutic effects

  • Dopamine agonists

  • Carbamazepine

  • Erythromycin, clarithromycin, fluoxetine, grapefruit juice

  • Cimetidine

  • Tranquilizers

  • Opiates

  • St. John’s wort

  • Phenytoin

  • Beta blockers

  • Insulin/oral hypoglycemic medications

  • Venlafaxine