Promethazine
Mechanism :
Promethazine is a phenothiazine derivative which differs structurally from the antipsychotic phenothiazines by the presence of a branched side chain and no ring substitution. Promethazine is an H1 receptor blocking agent. In addition to its antihistaminic action, it provides clinically useful sedative and antiemetic effects.
Indication :
- Sedation
- Antihistamine
- Nausea and vomiting
- Motion sickness
Contraindications :
Sensitivity to any of the components, patients receiving MAO inhibitors. Not recommended for children below 2 years of age.
Dosing :
<2 years,
safety and efficacy not established.
>2 years:
0.25-1 mg/kg PO/PR every 4-6 hours as and when required; Maximum dose: 25 mg/day.
Adverse Effect :
Dryness of the mouth, blurring of vision, dizziness or mild stimulation and insomnia may occur. Rare: leukopenia.
Interaction :
Potentials sedative effects of other drugs; avoid alcohol.
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 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unknown dialysability. Dose as in normal renal function |
| HD | Not dialysed. Dose as in normal renal function |
| HDF/High flux | Unknown dialysability. Dose as in normal renal function |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
Use in hepatic impairment is contraindicated as side effects of drug and CNS signs and symptoms of liver disease may be indistinguishable.