Chlorpromazine injection
THORAZINE IM
What it isIntramuscular D2 and 5-HT2A antagonist with strong H1, alpha-1, and muscarinic blockade; agitation, psychosis, emesis, and hiccups.
Why this oneIts parenteral intractable-hiccup indication is unusual among antipsychotics.
What limits itOrthostatic hypotension can be profound — keep the patient supine; local tissue irritation, antimuscarinic toxicity, and QT prolongation also matter.
FDA-approved for
- acute agitation / psychosis (~1954)
- intractable hiccups (~1954)
- nausea/vomiting (~1954)
FDA label
Read the full label on DailyMed ↗
BOXED WARNING Increased mortality in elderly patients with dementia-related psychosis; not approved for dementia-related psychosis.
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Acute schizophrenia/manic states (hospitalized) | Adults | 25 mg IM | Add 25–50 mg IM in 1 h if needed; increase over days | Up to 400 mg every 4–6 h in exceptionally severe cases |
| Nausea and vomiting | Adults | 25 mg IM | 25–50 mg IM every 3–4 h PRN until vomiting stops | |
| Presurgical apprehension | Adults | 12.5–25 mg IM 1–2 h before surgery | ||
| Intractable hiccups / acute intermittent porphyria / tetanus (adjunct) | Adults | 25–50 mg IM (hiccups/tetanus); 25 mg IM TID–QID (porphyria) | ||
| Severe behavioral problems / nausea and vomiting | Children 6 months–12 yr | 0.25 mg/lb IM every 6–8 h PRN | ≤5 yr (≤50 lb): 40 mg/day; 5–12 yr (50–100 lb): 75 mg/day |
Renal Use with caution in renal disease.
Hepatic Use with caution in hepatic disease; increased CNS sensitivity in cirrhosis/hepatic encephalopathy.
Instructions
- Inject slowly, deep into upper outer quadrant of the buttock
- Keep patient lying down ≥30 minutes after injection (hypotension)
- Reserve parenteral use for bedfast/acute cases; IV only for severe hiccups, surgery, tetanus
- Contains sulfites
Contraindications
- Comatose states or presence of large amounts of CNS depressants (alcohol, barbiturates, narcotics)
Cautions
- Tardive dyskinesia
- Neuroleptic malignant syndrome
- Hypotension (especially parenteral)
- Leukopenia/neutropenia/agranulocytosis
- Jaundice/hepatic effects
- Sulfite sensitivity
- Avoid in suspected Reye's syndrome
Adverse reactions
- Drowsiness
- Hypotension
- Extrapyramidal reactions
- Jaundice
- Hematologic disorders
- Anticholinergic effects
Pregnancy Undefined.
Lactation Undefined.
⚠ BOXED WARNING
- Increased mortality in elderly patients with dementia-related psychosis
Classes and tags
Clinical profile
Mechanism of action: Chlorpromazine injection ballicule
