Prochlorperazine
Mechanism :
Prochlorperazine is a phenothiazine derivative. It is used as an anti-emetic agent that acts by blocking the dopamine receptors.
Indication :
- Chemotherapy, radiotherapy induced vomiting
- Intractable vomiting
- Psychotic disorder
Contraindications :
Do not use in patients with known hypersensitivity to phenothiazines Do not use in comatose states or in the presence of large amounts of central nervous system depressants (alcohol, barbiturates, narcotics, etc.), in pediatric surgery, or in pediatric patients under 2 years of age or under 20 lbs. Do not use in children for conditions for which dosage has not been established.
Dosing :
<2 years:
Not recommended.
Severe Nausea and Vomiting:
≥2 years:
9-13 kg: 2.5 mg PO daily or 12 hourly; Maximum dose: 7.5 mg/day.
14-18 kg: 2.5 mg PO every 8-12 hours; Maximum dose: 10 mg/day.
19-37 kg: 2.5 mg PO 8 hourly or 5 mg PO every 12 hours; Maximum dose: 15 mg/day.
Psychotic disorder:
>2 years:
Initially 2.5 mg PO/PR every 8-12 hours.
Maximum dose:
20 mg/day in 2-6 years and 25 mg/day in 6-12 years; do not exceed 10 mg on day 1.
Adverse Effect :
Excitation, weakness, cerebral edema, poikilothermia, ECG changes, tachycardia, agitation, dry mouth, nasal stuffiness and insomnia. Extrapyramidal symptoms may occur. Rarely neuroleptic malignant syndrome may occur. In susceptible patients, respiratory depression may occur. Postural hypotension has also been reported.
Interaction :
Metoclopramide and Lithium: Increased extrapyramidal side-effects with metoclopramide and lithium.
Antiepileptics: Decreased effect of antiepileptics.
Antacids: Decreased levels with antacids.
Anxiolytics and Hypnotics: Enhanced sedative effects with anxiolytics and hypnotics.
Deferoxamine: Avoid with deferoxamine.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Start with small doses, i.e. 6.25 mg IM or 5 mg orally |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unlikely to be dialysed. Dose as in GFR<10 mL/min |
| HD | Unlikely to be dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Unknown dialysability. Dose as in GFR<10 mL/min |
| CAV/VVHD | Unlikely to be dialysed. Dose as in normal renal function |
Hepatic Dose :
Dose adjustment guidelines are not available. Dose adjustment may be required due to high hepatic metabolism. Hepatic impairment will increase exposure to drug, reduction of dose is reasonable.