Chlorpromazine
Mechanism :
The precise mechanism of action of Chlorpromazine is not known. The principal pharmacological actions are psychotropic. It also exerts sedative and antiemetic activity. Chlorpromazine has actions at all levels of the central nervous system, primarily at subcortical levels, as well as on multiple organ systems. Chlorpromazine has strong antiadrenergic and weaker peripheral anticholinergic activity; ganglionic blocking action is relatively slight. It also possesses slight antihistaminic and antiserotonin activity.
Indication :
- Schizophrenia
- Mania
- Agitation
- Hiccups
- Behavioural disorder, hyperactivity
- Narcotic withdrawal
- Nausea and vomiting
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 like alcohol, barbiturates and narcotics.
Dosing :
Behavioral disorders:
5 months-12 years:
2.5-6 mg/kg/day PO QDS or 2.5-4 mg/kg/day IM 6-8 hourly, (Maximum 50 mg/day PO and 40 mg/day IM in 6 months-5 years; maximum 200 mg/day PO and 75 mg/day in 5-12 years).
12-18 years:
200-400 mg/day PO in 3-4 doses, can increase every 3rd day to max 1000 mg/day.
Intractable hiccup/Acute intermittent porphyria:
6-12 years:
10 mg/dose 1-3 times daily.
12-18 years:
25-50 mg/dose PO 3-4 times daily.
Nausea and vomiting:
≥6 months-12 years:
0.55 mg/kg oral/IM every 6-8 hours (Maximum 50 mg/day PO and 40 mg/day IM in 6 months-5 years; maximum 200 mg/day PO and 75 mg/day in 5-12 years)
12-18 years:
10-25 mg PO/IM every 4-6 hours, can increase every 3rd day to max 1000 mg/day.
For pre-op to prevent nausea/vomiting:
≥6 months-12 years:
0.25 mg/kg IM ½ hour before procedure or 2 mg IV 2-5 mins before procedure.
12-18 years:
12.5 mg/kg IM ½ hour before procedure or 1 mg IV 2-5 mins before procedure.
Adjunct treatment in tetanus:
≥6 months-12 years:
0.5 mg/kg IM/IV every 6-8 hours. Maximum 40 mg/day IM in
6 months-5 years;
maximum 75 mg/day in 5-12 years.
12-18 years:
25-50 IM every 6-8 hours
Adverse Effect :
Extrapyramidal symptoms, anti-muscarinic effects, erectile dysfunction, oligomenorrhoea or amenorrhea, weight gain.
Interaction :
Astemizole, Stall, Cisapride, Indapamide, Procainamide, Quinidine: Increase QT interval.
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 dose and increase according to response |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Not dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Unknown dialysability. Dose as in GFR<10 mL/min |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
Use with caution as patients with hepatic disease may have decrease drug metabolism. Discontinue if patient has jaundice.