Chlorpromazine Pharmacology


About Chlorpromazine
Aliphatic phenothiazine derivative, First-Generation Antipsychotic(typical), anticholinergic, antidopaminergic, antihistaminic, and antiadrenergic, Tranquilizer, Antiemetic
Mechanism of Action of Chlorpromazine
Antipsychotic action: Chlorpromazine binds to the dopamine receptor (D1, D2, D3 &D4).It exerts its antipsychotic activity by blocking the dopamine projections in the limbic system and in mesocortical area. Peripherally and centrally it acts as a competitive Dopamine antagonist. Chlorpromazine also produces alpha adrenergic blocking activity and anticholinergic activity. It also produces weak H1 antihistaminic activity and anti serotonin activity.
Antiemetic action: Chlorpromazine exerts its antiemetic action by blocking the dopamine receptor in the medullary chemoreceptor trigger zone.
Antimigraine action: Chlorpromazine has been used in migraine to control severe nausea and vomiting unresponsive to Antiemetics and to relieve the pain of severe migraine attacks unresponsive to parenteral Dihydroergotamine or Sumatriptan.
Anaesthetic adjuncts: It is used as anaesthetic adjunct since it allays anxiety, smoothen induction and produce antiemetic action.
Pharmacokinets of Chlorpromazine
Absorption: It is absorbed after oral administration. Absorption rate varies with route of administration. Distribution: It is distributed widely in the body in protein bound form. Metabolism: It is metabolised in the liver and produce both active and inactive metabolites. Excretion: It is excreted mainly through urine. Small amount of drug is excreted through faeces and breast milk.
Onset of Action for Chlorpromazine
30-60 minutes
Duration of Action for Chlorpromazine
4 - 6 hour
Half Life of Chlorpromazine
16 - 30 hours
Side Effects of Chlorpromazine
1.Tardive dyskinesia
2.Extrapyramidal reactions
7.Dry mouth
9.Blurred vision
13.Urine retention
14.Cholestatic jaundice
15.Aplastic anaemia
16.Pain at injection site.
Contra-indications of Chlorpromazine
1.Hypersensitivity to Chlorpromazine and other Phenothiazines
3.Bone marrow depression
Special Precautions while taking Chlorpromazine
1.Renal impairment
2.Hepatic impairment
3.Cardiovascular disease
7.Respiratory disorder
8.Prostatic hyperplasia
9.Ceribrovascular disorder
10.Patient on ECT
11.Reaction to Insulin
12.Patient exposed to extreme heat or cold or phosphorus insecticides
13.Slowly withdraw the drug with caution
Pregnancy Related Information
Old Age Related Information
Use with caution
Breast Feeding Related Information
Children Related Information
Use with caution
CHILDREN (below 6 months): Contraindicated
Indications for Chlorpromazine
2.Nausea and vomiting
3.Relief of apprehension and restlessness before surgery
4.Acute intermittent Porphyria
5.Intractable hiccups
6.Manic depressive illness
7.Behavioral problems in children
Interactions for Chlorpromazine
Alcohol: CNS depression, extrapyramidal reactions.
Aluminium salts: Decrease efficacy. Antacids should be given 1 hour before or 2 hours after chlorpromazine administration.
Anticholinergics: Decrease efficacy and increase the anticholinergic side effects of chlorpromazine.
Barbiturates: Decreases efficacy.
Barbiturate anaesthetics: Increase frequency and severity of neuromuscular excitation and hypotension.
Bromocriptine: Efficacy decreased by chlorpromazine.
Charcoal: Prevents absorption of chlorpromazine.
Epinephrine, Norepinephrine: Pressor effect decreased, peripheral vasoconstrictive effect antagonised.
Lithium: Disorientation, unconsciousness and extrapyramidal symptoms.
Meperidine: Excessive sedation and hypotension.
TCAs: Serum concentration increased by chlorpromazine.
Valproic acid: Efficacy potentiated.
Propranolol: Increased plasma levels of both drugs.
MAOIs: Additive orthostatic hypotensive effect.
Lab. Tests: Pregnancy tests: False positive results.
Plasma bound iodine (PBI): Increase in PBI occurs.
Typical Dosage for Chlorpromazine
Psychoses: 25 mg 3 times a day. Dose can be gradually increased up to 800 mg / day
Maintenance dose: 75 - 300 mg / day in 3 divided doses
Nausea and vomiting: 40 - 100 mg / day in 4 divided doses. Dose can be increased if necessary.
Relief of apprehension and restlessness before surgery: 25 - 50 mg given 2 - 3 hour before surgery. If necessary the drug can be given during surgery dose is 12.5 mg as IM injection.
Acute intermittent Porphyria, Intractable hiccups: 25 - 50 mg every 6 - 8 hourly
Migraine: 12.5 mg as IV and is repeated every 20minutes up to 37.5 mg
Behavioral problems in children: 0.55 mg/ kg/ dose 4 - 6 times a day. Dose can be increased depending on the severity of patient`s condition
Schedule of Chlorpromazine
Storage Requirements for Chlorpromazine
The drug should be kept at 15-30 degree C in a tightly closed container. Protect from heat and light. Keep out of the reach of children
Effects of Missed Dosage of Chlorpromazine
Take the missed dose as soon as noticed and if it is the time to take the next dose then skip the missed dose.
Effects of Overdose of Chlorpromazine
Give supportive measures and symptomatic treatment.

Home Delivery for Chlorpromazine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including chlorpromazine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for chlorpromazine and other medicines and health products. Home delivery services for chlorpromazine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take chlorpromazine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for chlorpromazine before they complete the sale. You can get this information while placing the order for chlorpromazine with the pharmacy.

Chlorpromazine is a generic medicine name and there are several brands available for it. Some of the brands for chlorpromazine might be better known than chlorpromazine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have chlorpromazine in stock, you can ask for one of the branded alternatives for chlorpromazine.