Typical Antipsychotics

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Summary

Typical antipsychotics are a class of drugs that include haloperidol and fluphenazine. As their name suggests, the typical antipsychotics are used to treat psychosis and psychotic disorders like schizophrenia, as well as dangerous agitation and aggression. Side effects include extrapyramidal symptoms, abbreviated EPS, neuroleptic malignant syndrome, abbreviated NMS, drowsiness or sedation, anticholinergic effects, and a prolonged QT interval that puts the patient at risk for torsade de pointes.

Key Points

  • Typical Antipsychotics
    • Also known as first-generation antipsychotics
    • Key Drugs
      • Haloperidol
      • Fluphenazine
      • Thioridazine
      • Chlorpromazine
      • Loxapine
    • Mechanism
      • Blocks D2 dopamine receptors and alters the effect of dopamine on the CNS
      • When administered intramuscularly:
        • Administered via a large bore needle due to the viscosity of the medication
        • Should be administered via z-track, rotate injection sites
    • Clinical Use
      • Psychotic states
        • Schizophrenia
          • Typical antipsychotics are not considered first-line treatment
            • Targets the positive symptoms (hallucinations, delusions, thought disorders) but has minimal effect on negative symptoms (flat affect, apathy, antisocial behavior, etc.)
        • Mania with Psychotic Symptoms
          • Bipolar Type 1
        • Postpartum psychosis
      • Acute Agitation
        • Used intramuscularly as a pharmacological restraint
      • Tourette Syndrome
    • Side Effects and Adverse Reactions
      • Extrapyramidal Symptoms (EPS)
        • Drug-induced movement disorders
          • Dystonia
            • Muscle contraction, spasm, stiffness
          • Pseudoparkinsonism
            • Mimics Parkinson’s disease with a shuffling gait, bradykinesia, tremor, rigidity
          • Akathisia
            • Restlessness
          • Tardive Dyskinesia (TD)
            • Involuntary repetitive movements, often of the mouth, face, and neck (e.g. lip smacking, sticking out tongue, grimacing)
            • Appears with long-term use
        • Can be treated with the drug benztropine
        • EPS is common, but still an adverse effect that should receive medical attention. Notify the provider if EPS is noticed.
      • Neuroleptic Malignant Syndrome (NMS)
        • Life threatening, a medical emergency
        • Manifests with a fever, muscle rigidity, altered mental status, and unstable vital signs
        • All antipsychotics should be held and provider notified immediately
      • Sedation / Drowsiness
        • This is an expected side effect
        • Avoid alcohol and other CNS depressants to prevent oversedation
      • Anticholinergic effects
        • Dry mouth, dry eyes, urinary retention, tachycardia, constipation, etc.
        • This is an expected side effect
      • QT prolongation
        • Can lead to an ventricular arrhythmia known as torsades de pointes
      • Photosensitivity
      • Orthostatic hypotension
        • Move positions slowly to avoid sudden drop in blood pressure