Drug Information

    


     











Pharmacokinetics




Promethazine is well absorbed
after oral or intramuscular administration. Peak plasma concentrations
have been observed 2 to 3 hours after administration by these routes,
although there is low systemic bioavailability after oral
administration, due to high first-pass metabolism in the liver.
Promethazine crosses the blood-brain barrier and the placenta, and is
distributed into breast milk. Values ranging from 76 to 93% have been
reported for plasma-protein binding. Promethazine undergoes extensive
metabolism, predominantly to promethazine sulphoxide, and also to N-desmethylpromethazine.
It is excreted slowly via the urine and bile, chiefly as metabolites.
Elimination half-lives of 5 to 14 hours have been reported.

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Indication
& Dosage






Oral

ALLERGIC CONDITIONS: 25mg at night and 10mg during the day.

Parenteral

SEVERE ALLERGY: 25-50mg deep IM (max 100mg). Children (5-10yrs): IM
6.25-12.5mg) Slow IV inj (in emergencies): 25-50mg (upto 100mg).

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Action




A phenothiazine which has very little dopaminergic action. It
is primarily an antithistamine with additional sedative and antiemetic
actions.

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Interaction

Alcohol:
CNS depression, extra-pyramidal reaction.

Aluminium Salts: Decrease efficacy. Antacids should be given 1 hour
before or 2 hours after promethazine.

Anticholinergics: Decrease efficacy and increase the anticholinergic
side-effects of promethazine.

Barbiturate anaesthetics: Increase frequency and severtiy of
neuromuscular excitation and hypotension.

Bromocriptine: Efficacy decreased by promethazine.

Lithium: Disorientation, unconsciousness and extra-pyramidal symptoms.

Meperidine: Excessive sedation and hypotension.

TCAs: Serum concentration increased by promethazine.

Propranolol: Increased plasma levels of both drugs.

MAOIs: Additive orhtostatic hypotensive effect.

Lab Test: Pregnancy tests: False positive results.

Plasma bound iodine(PBI): Increase in PBI occurs.

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Adverse Effect & Precautions




Dry mouth, epigastric distress, restlessness, blurred vision, skin rash.



Precaution: Hypersensitivity.

Pregnancy: Contraindicated.

Breast Feeding: Contraindicated.

Man:May be given in reduced dose.

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Brands
available in market



















AVOMINE

Rhone-Poulenc
TAB 25mg 10 9.20
PHENA

Ind-Swift
SYRUP 5mg/ml 60ml 11.98
PHENERGAN

Rhone-Poulenc
TAB 10mg 10 4.49
TAB 25mg 10 7.04
SYRUP 5mg/ml 60ml 13.08
ELIX 5mg/ml 400ml 43.28
INJ 25mg/ml 10x2ml 35.30
PROMETHAZINE

Jagsonpal
SYRUP 5mg/5ml 450ml 24.50



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Drug Information
    

     

Pharmacokinetics

Promethazine is well absorbed after oral or intramuscular administration. Peak plasma concentrations have been observed 2 to 3 hours after administration by these routes, although there is low systemic bioavailability after oral administration, due to high first-pass metabolism in the liver. Promethazine crosses the blood-brain barrier and the placenta, and is distributed into breast milk. Values ranging from 76 to 93% have been reported for plasma-protein binding. Promethazine undergoes extensive metabolism, predominantly to promethazine sulphoxide, and also to N-desmethylpromethazine. It is excreted slowly via the urine and bile, chiefly as metabolites. Elimination half-lives of 5 to 14 hours have been reported.

Top
   

Indication & Dosage


Oral
ALLERGIC CONDITIONS: 25mg at night and 10mg during the day.
Parenteral
SEVERE ALLERGY: 25-50mg deep IM (max 100mg). Children (5-10yrs): IM 6.25-12.5mg) Slow IV inj (in emergencies): 25-50mg (upto 100mg).

Top
   

Action

A phenothiazine which has very little dopaminergic action. It is primarily an antithistamine with additional sedative and antiemetic actions.

Top
   

Interaction

Alcohol: CNS depression, extra-pyramidal reaction.
Aluminium Salts: Decrease efficacy. Antacids should be given 1 hour before or 2 hours after promethazine.
Anticholinergics: Decrease efficacy and increase the anticholinergic side-effects of promethazine.
Barbiturate anaesthetics: Increase frequency and severtiy of neuromuscular excitation and hypotension.
Bromocriptine: Efficacy decreased by promethazine.
Lithium: Disorientation, unconsciousness and extra-pyramidal symptoms.
Meperidine: Excessive sedation and hypotension.
TCAs: Serum concentration increased by promethazine.
Propranolol: Increased plasma levels of both drugs.
MAOIs: Additive orhtostatic hypotensive effect.
Lab Test: Pregnancy tests: False positive results.
Plasma bound iodine(PBI): Increase in PBI occurs.

Top
   

Adverse Effect & Precautions

Dry mouth, epigastric distress, restlessness, blurred vision, skin rash.

Precaution: Hypersensitivity.
Pregnancy: Contraindicated.
Breast Feeding: Contraindicated.
Man:May be given in reduced dose.

Top
   

AVOMINE

Rhone-Poulenc

TAB

25mg

10

9.20

PHENA

Ind-Swift

SYRUP

5mg/ml

60ml

11.98

PHENERGAN

Rhone-Poulenc

TAB

10mg

10

4.49

TAB

25mg

10

7.04

SYRUP

5mg/ml

60ml

13.08

ELIX

5mg/ml

400ml

43.28

INJ

25mg/ml

10x2ml

35.30

PROMETHAZINE

Jagsonpal

SYRUP

5mg/5ml

450ml

24.50

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By |2022-07-20T16:41:35+00:00July 20, 2022|Uncategorized|Comments Off on Promethazine

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