Thioridazine Pharmacology

Thioridazine

About Thioridazine
First-Generation Antipsychotic,Piperidyl phenothiazine, Typical Antipsychotic.
Mechanism of Action of Thioridazine
Thioridazine 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. Thioridazine also produces alpha adrenergic blocking activity and anticholinergic activity. It also produces weak H1 antihistaminic activity and anti serotonin activity.
Pharmacokinets of Thioridazine
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 .
Excretion: It is excreted mainly through urine. Small amount of drug is excreted through faeces and breast milk.
Onset of Action for Thioridazine
30 - 60 minutes
Duration of Action for Thioridazine
4 - 6 hour
Half Life of Thioridazine
N/A
Side Effects of Thioridazine
1. Tardive dyskinesia
2. Extrapyramidal reactions
3. Drowsiness
4. Sedation
5. Dizziness
6. Hypotension
7. Dry mouth
8. Constipation
9. Blurred vision
10. Agranulocytosis
11. Photosensitivity
12. Insomnia
13. Urine retention
14. Cholestatic jaundice
Contra-indications of Thioridazine
1. Hypersensitivity to Thioridazine and other Phenothiazines
2. Comatose
3. Blood dyscrasias
4. Patient taking antidepressants
Special Precautions while taking Thioridazine
1. Renal impairment
2. Hepatic impairment
3. Cardiovascular disease
4. Pheochromocytoma
5. Hypocalcaemia
6. Epilepsy
7. Hypotension
8. Patient exposed to extreme heat or cold or phosphorus insecticides
9. Ceribrovascular disorder
10. Patient on ECT
11. Reaction to Insulin
12. Prostatic hyperplasia
13. Glaucoma
14. Slowly withdraw the drug with caution
15. Do not drive vehicle or operate machines or involve in any hazardous activities
Pregnancy Related Information
Contraindicated
Old Age Related Information
Use with caution
Breast Feeding Related Information
Contraindicated
Children Related Information
Use with caution
Below 2 years : Contraindicated
Indications for Thioridazine
1. Psychoses
2. Schizophrenia
3. Behavioural disturbances
Interactions for Thioridazine
Alcohol: CNS depression, extra-pyramidal reactions.
Aluminium salts: Decrease efficacy. Antacids should be given 1 hour before or 2 hours after adminstration of thioridazine.
Anticholinergics: Decrease efficacy and increase the anticholinergic side effects of thioridazine.
Barbiturates: Decreases efficacy.
Barbiturate anaesthetics: Increase frequency and severity of neuromuscular excitation and hypotension.
Bromocriptine: Efficacy decreased by thioridazine.
Charcoal: Prevents absorption of thioridazine.
Epinephrine, Norepinephrine: Pressor effect decreased, peripheral vasoconstrictive effect antagonised.
Lithium: Disorientation, unconsciousness and extra-pyramidal symptoms.
Meperidine: Excessive sedation and hypotension.
TCAs: Serum concentration increased by thioridazine.
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 Thioridazine
Adult:
Psychoses, Schizophrenia: 150 - 300 mg / day in 3 divided doses. The dose can be gradually increased.
Maximum dose: 800 mg / day
Behavioral disturbances: 75 mg / day in 3 divided doses
Maintenance dose: 20 - 200 mg daily

Children: 1 mg / kg / day in divided doses
Schedule of Thioridazine
H
Storage Requirements for Thioridazine
The drug should be kept at 25 degree C in a tightly closed container. Protect from heat and light.
Effects of Missed Dosage of Thioridazine
Take the missed dose as soon as noticed and if it is the time to take the next dose then skip the missed dose.Do not double the dose.
Effects of Overdose of Thioridazine
Give supportive measures and treatment. Gastric lavage has to be done. Activated charcoal can be given to reduce the absorption of the drug. Hypotension can be treated with IV fluids, seizure with Diazepam or Barbiturates, arrhythmia with Phenytoin and extra pyramidal reactions with Benztropine.

Home Delivery for Thioridazine in Your City

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

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 thioridazine and other medicines and health products. Home delivery services for thioridazine 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 thioridazine 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 thioridazine before they complete the sale. You can get this information while placing the order for thioridazine with the pharmacy.

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