THERAPEUTICS

Brands

• Compazine, Stemetil, Buccastem

Generic?

• Yes

Class

• Antipsychotic, antiemetic

Commonly Prescribed for

(FDA approved in bold)

• Schizophrenia

• Non-psychotic anxiety in adults

• Severe nausea and vomiting

• Migraine (acute)

• Vertigo and labyrinthine disorders

• Mania in bipolar disorder

How the Drug Works

• Dopamine receptor antagonist with greater action at D2 receptors. Also blocks serotonin 5-HT2A receptors, α1-adrenergic receptors and is an antihistamine

How Long Until It Works

• Injection effective within 10 minutes, oral 1–2 hours

If It Works

• Use at lowest effective dose

• Continue to assess effect of the medication and if it is still needed

If It Doesn't Work

• Increase dose, or discontinue and change to another agent

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Migraine: often combined with NSAIDs and triptans or ergots

• Nausea and vomiting: corticosteroids

Tests

• Monitor weight, blood pressure, lipids, and fasting glucose with frequent chronic use. Obtain blood pressure and pulse before initial IV use and monitor QTc with ECG

ADVERSE EFFECTS (AEs) How the Drug Causes AEs

• Motor AEs and prolactinemia: blocking of D2 receptors

• Hypotension: blocking of α1-adrenergic receptors

Notable AEs

• Most common: dizziness, sedation, dry mouth, constipation, skin changes

• Tachycardia, hypo or hypertension

• Akathisia, parkinsonism

• Interference with thermoregulatory mechanisms

Life-Threatening or Dangerous AEs

• Tardive dyskinesia

• ECG changes including prolongation of QTc. Rarely cardiac arrest

Weight Gain

• Common (with frequent use)]

Sedation

• Common

What to Do About AEs

• Rarely causes ECG changes. Use with caution if QTc is above 450 (women) or 440 (men) and do not administer with QTc greater than 500

• If excessive sedation occurs, use only as a rescue agent for inpatients or when patients can lie down or sleep

Best Augmenting Agents to Reduce AEs

• Give fluids to avoid hypotension, tachycardia, and dizziness

• Give anticholinergics (diphenhydramine or benztropine) or benzodiazepines for extrapyramidal reactions