Compazine, Stemetil 
Classifications: psychotherapeutic; antipsychotic phenothiazine; gastrointestinal agent; antiemetic
Pregnancy Category: C


5 mg, 10 mg, 25 mg tablets; 10 mg, 15 mg, 30 mg sustained release capsule; 2.5 mg, 5 mg, 25 mg suppositories; 5 mg/mL injection

Edisylate 5 mg/5 mL syrup, 5 mg/mL injection


Phenothiazine derivative similar to chlorpromazine. Mechanism that produces strong antipsychotic effects is unclear, but thought to be related to blockade of postsynaptic dopamine receptors in the brain. Action on the hypothalamus and reticular formation results in sedative effects. Antiemetic effect is produced by suppression of the chemoreceptor trigger zone (CTZ).

Therapeutic Effects

Inhibits dopamine reuptake; may be basis for moderate extrapyramidal symptoms. Greater extrapyramidal effects and antiemetic potency but fewer sedative, hypotensive, and anticholinergic effects than chlorpromazine.


Management of manifestations of psychotic disorders, of excessive anxiety, tension, and agitation, and to control severe nausea and vomiting.


Hypersensitivity to phenothiazines; bone marrow depression; comatose or severely depressed states; children <9 kg (20 lb) or 2 y of age; pediatric surgery; short-term vomiting in children or vomiting of unknown etiology; Reye's syndrome or other encephalopathies; history of dyskinetic reactions or epilepsy; pregnancy (category C), lactation.

Cautious Use

Patient with previously diagnosed breast cancer, children with acute illness or dehydration.

Route & Dosage

Severe Nausea, Vomiting, Anxiety, Psychotic Disorders
Adult: PO 5–10 mg t.i.d. or q.i.d.; sustained release: 10–15 mg q12h IM 5–10 mg q3–4h up to 40 mg/d IV 2.5–10 mg q6–8h (max: 40 mg/d) PR 25 mg b.i.d.
Child: PO 2.5 mg 1–3 times/d or 5 mg b.i.d. (max: 15 mg/d) IM 0.13 mg/kg q3–4h PR 2.5 mg b.i.d. or t.i.d. up to 20–25 mg/d



PREPARE: Direct: Dilute each 5 mg (1 mL) in 4 mL of NS or other compatible solution to yield 1 mg/mL.  IV Infusion: Dilute in 50–100 mL of D5W, NS, D5/0.45% NaCl, RL or other compatible solution.  

ADMINISTER: Direct: Do not exceed 10 mg for a single dose. Do not give a bolus dose. Give at a maximum rate of 5 mg/min.   IV Infusion: Give over 15–30 min. Do not exceed direct IV rate.  

INCOMPATIBILITIES Solution/additive: Aminophylline, amphotericin B, ampicillin, calcium gluceptate, calcium gluconate, cephalothin, chloramphenicol, chlorothiazide, dimenhydrinate, furosemide, hydrocortisone, ketorolac, methohexital, midazolam, morphine, penicillin G sodium, pentobarbital, phenobarbital, sodium bicarbonate, dimenhydrinate, hydromorphone, thiopental. Y-site: Aldesleukin, allopurinol, amifostine, amphotericin B cholesteryl complex, aztreonam, cefepime, etoposide, fludarabine, foscarnet, filgrastim, piperacillin-tazobactam.

  • Discard markedly discolored solutions; slight yellowing does not appear to alter potency.

Adverse Effects (1%)

CNS: Drowsiness, dizziness, extrapyramidal reactions (akathisia, dystonia or parkinsonism), persistent tardive dyskinesia, acute catatonia. CV: Hypotension. GI: Cholestatic jaundice. Skin: Contact dermatitis, photosensitivity. Endocrine: Galactorrhea, amenorrhea. Special Senses: Blurred vision. Hematologic: Leukopenia, agranulocytosis.


Drug: Alcohol, cns depressants increase CNS depression; antacids, antidiarrheals decrease absorption, therefore, administer 2 h apart; phenobarbital increases metabolism of prochlorperazine; general anesthetics increase excitation and hypotension; antagonizes antihypertensive action of guanethidine; phenylpropanolamine poses possibility of sudden death; tricyclic antidepressants intensify hypotensive and anticholinergic effects; decreases seizure threshold—anticonvulsant dosage may need to be increased. Herbal: Kava-kava may increase risk and severity of dystonic reactions.


Absorption: Readily absorbed from GI tract. Onset: 30–40 min PO; 60 min PR; 10–20 min IM. Duration: 3–4 h PO; 10–12 h sustained release PO; 3–4 h PR; up to 12 h IM. Distribution: Crosses placenta; distributed into breast milk. Metabolism: Metabolized in liver. Elimination: Excreted in urine.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug