Compazine

Action

Exerts anticholinergic, CNS depressant, and antihistaminic effects. Depresses release of hypothalamic and hypophyseal hormones, decreases sensitivity of middle-ear labyrinth, and reduces conduction in vestibular-cerebellar pathways.

Availability

Capsules (extended-release, maleate): 10 mg, 15 mg, 30 mg

Injection (edisylate): 5 mg/ml

Oral solution (edisylate): 5 mg/5 ml

Suppositories: 2.5 mg, 5 mg, 25 mg

Tablets: 5 mg, 10 mg, 25 mg

Indications and dosages

➣ Nausea

Adults: 5 to 10 mg P.O. three to four times daily or 15 mg P.O. once daily or 10 mg P.O. (extended-release) b.i.d., up to 40 mg/day. Or 2.5 to 10 mg I.V., not to exceed 40 mg/day.

Children weighing 18 to 38 kg (40 to 85 lb): 2.5 mg P.O. or P.R. t.i.d. or 5 mg P.O. or P.R. b.i.d., not to exceed 15 mg/day

Children weighing 13.6 to 17.7 kg (30 to 39 lb): 2.5 mg P.O. or P.R. two or three times daily, not to exceed 10 mg/day

Children weighing 9 to 13 kg (20 to 29 lb): 2.5 mg P.O. or P.R. daily to b.i.d., not to exceed 7.5 mg/day

➣ Nausea and vomiting related to surgery

Adults: 5 to 10 mg I.V. 15 to 30 minutes before anesthesia induction, repeated once if necessary; or 5 to 10 mg I.M. 1 to 2 hours before anesthesia induction, repeated once in 30 minutes if necessary

➣ Schizophrenia

Adults and children older than age 12: For mild symptoms, 5 to 10 mg P.O. three to four times daily; for moderate to severe symptoms in hospitalized or supervised patients, 10 mg P.O. three to four times daily, increased p.r.n. q 2 to 3 days to 50 to 75 mg P.O. daily or up to 150 mg/day as tolerated p.r.n. for more severely disturbed patients. Or 10 to 20 mg I.M.; may repeat q 2 to 4 hours for up to four doses p.r.n.

Children ages 2 to 12: Initially, 2.5 mg P.O. or P.R. two or three times daily (maximum of 10 mg on day 1); then increase based on response. Don't exceed 25 mg/day for children ages 6 to 12 or 20 mg/day for children ages 2 to 5.

➣ Anxiety

Adults and children older than age 12: 5 mg P.O. three to four times daily; or 15 mg P.O. (extended-release) once daily or 10 mg P.O. (extended-release) q 12 hours; up to 20 mg/day for a maximum of 12 weeks

Off-label uses

• Migraine

Contraindications

• Hypersensitivity to drug or other phenothiazines

• Coma

• Concurrent use of large amounts of CNS depressants

• Pediatric surgery

• Children younger than age 2 or weighing less than 9 kg (20 lb)

Precautions

Use cautiously in:

• cardiovascular or hepatic disease, glaucoma, seizures

• anticipated exposure to extreme heat

• children with acute illness.

Administration

• For I.V. infusion, dilute 20 mg in 1 L of compatible I.V. solution, such as normal saline solution.

• Don't mix in same syringe with other drugs.

• Know that injection solution may cause contact dermatitis. Don't get it on hands or clothing.

See Give I.V. by slow infusion only. Don't give as bolus.

• Know that I.M. injection is not preferred because it can cause local irritation. However, if I.M. route is prescribed, inject deep into upper outer quadrant of gluteal area.

• Don't give by subcutaneous route.

• After desired response, switch to P.O. form as prescribed.

• When infusing I.V., watch for hypotension. Keep patient supine for 30 minutes after infusion.

Adverse reactions

CNS: sedation, extrapyramidal reactions, tardive dyskinesia, neuroleptic malignant syndrome

CV: orthostatic hypotension, ECG changes, tachycardia

EENT: blurred vision, lens opacities, pigmentary retinopathy, dry eyes

GI: constipation, ileus, dry mouth, anorexia

GU: pink or reddish-brown urine, urinary retention, galactorrhea

Hematologic: agranulocytosis, leukopenia

Hepatic: cholestatic jaundice, hepatitis Metabolic: hyperthermia

Skin: photosensitivity, pigmentation changes, rash

Other: allergic reactions

Interactions

Drug-drug. Anticonvulsants: reduced seizure threshold

Antineoplastics: masking of antineoplastic toxicity

CNS depressants (including antihistamines, anticholinergics, opioids, other phenothiazines, sedative-hypnotics): additive CNS depression

Guanethidine: inhibition of antihypertensive effects

Oral anticoagulants: decreased anticoagulant effect

Phenytoin: increased or decreased phenytoin blood level Propranolol: increased blood levels of both drugs

Thiazide diuretics: increased risk of orthostatic hypotension

Drug-diagnostic tests. Liver function tests: abnormal results

Phenylketonuria test: false-positive result

Drug-herbs. Betel nut: increased risk of extrapyramidal reactions

Evening primrose oil: increased risk of seizures

Kava: increased risk of drug-related adverse reactions

Drug-behaviors. Alcohol use: additive CNS depression

Patient monitoring

See Monitor neurologic status, especially for signs and symptoms of neuroleptic malignant syndrome (high fever, sweating, unstable blood pressure, stupor, muscle rigidity, and autonomic dysfunction).

• In long-term therapy, assess for other adverse CNS effects, including extrapyramidal symptoms and tardive dyskinesia.

• Monitor patient closely if he's receiving drug for nausea and vomiting associated with chemotherapy, because it may mask symptoms of chemotherapy toxicity.

• Evaluate CBC and liver function tests.

Patient teaching

• Instruct patient to dilute oral solution with tomato or fruit juice, milk, coffee, soda, tea, water, or soup.

See Teach patient to recognize and immediately report signs and symptoms of an allergic reaction or neuroleptic malignant syndrome.

• Inform patient about drug's other CNS effects. Tell him to contact prescriber if these occur.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, alertness, and motor skills.

• Tell patient drug may turn urine pink or reddish brown.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.