Amitriptyline Pharmacology

Amitriptyline

About Amitriptyline
Tricyclic Antidepressant (Tertiary Amine), anticholinergic.
Mechanism of Action of Amitriptyline
Amitriptyline acts by inhibiting the re-uptake of Noradrenaline and Serotonin (5 HT) in the CNS nerve terminals .This will result in an increased concentration of neurotransmitters in the synaptic cleft and produces antidepressant effect. Amitriptyline more selectively inhibit reuptake of Serotonin than Noradrenaline. Amitriptyline also has anticholinergic activity.
It is also useful in migraine prophylaxis. The monoamine uptake blocking property is related to migraine prophylactic activity. These are suited for patient with depression.
Pharmacokinets of Amitriptyline
Absorption: Amitriptyline is rapidly absorbed after oral administration. Distribution: It is widely distributed in the body in protein bound form Metabolism: Imipramine is metabolised in the liver to the active metabolite Nortriptyline. Excretion: Drug is excreted mainly through urine
Onset of Action for Amitriptyline
2 - 6 weeks
Duration of Action for Amitriptyline
Up to 6 weeks
Half Life of Amitriptyline
20 - 30 hours
Side Effects of Amitriptyline
1.Drowsiness
2 Dizziness
3.Nausea
4.Vomiting
5.Blurred vision
6.Difficulty in micturition
7.Tachycardia
8.Hypotension
9.Arrhythmia
10.Dryness of mouth
11.Constipation
12.Confusion
13.Headache
14.Sedation
15.Agranulocytosis
16.Urticaria
17.Rash
18.Jaundice
19.Anorexia
20.Impotence
21.Loss of libido
22.Galactorrhea
23.Gynecomastia
Contra-indications of Amitriptyline
1.Hypersensitivity to Amitriptyline
2.Myocardial infarction
3.CHF
4.Severe liver disease
Special Precautions while taking Amitriptyline
1.Renal impairment
2.Hepatic impairment
3.Cardiac arrhythmia
4.Myocardial infarction
5.Tachycardia,
6.Heart failure
7.Strokes
8. Angle closure glaucoma
9.History of urine retention
10. Increased intraocular pressure
11.Hyperthyroidism,
12.Alcoholics
13.Patient at risk for suicide
14. Slowly withdraw the drug with caution
15.Patient should be cautioned against driving vehicle, operating machine and activities requiring mental alertness or judgment
Pregnancy Related Information
Use with caution.
Old Age Related Information
Use with caution.
Breast Feeding Related Information
Use with caution.
Children Related Information
Use with caution
CHILDREN< 12 years: contraindicated
NEONATES: contraindicated
Indications for Amitriptyline
1.Depression,
2.Prophylaxis of migraine,
3.Bulimia nervosa,
4.Nocturnal enuresis.
Interactions for Amitriptyline
Anticholinergics : Enhanced effect of anticholinergics may occur.
Barbiturates : Serum level of amitriptyline decreased; additive respiratory depressant effect.
Clonidine : Hypertensive crisis.
Dicoumarol : Increase in anticoagulation effects.
Disulfiram : Acute organic brain syndrome.
Fluoxetine & Haloperidol : Potentiate action of amitriptyline.
Levodopa : Its bioavailability is reduced, hypertensive episodes.
MAOIs, Furazolidone : Seizures, sweating, coma, hyperexcitabilty, hyperthermia, tachycardia, mydriasis, confusion, DIC. (Disseminated Intravascular Coagulation) and death.
Oral Contraceptives and Phenothiazines : Increase plasma levels of imipramine.
Smoking : Increases metabolic bio-transformation.
Alcohol : Sedative effect of alcohol potentiated.
Typical Dosage for Amitriptyline
Adult: 25 mg 3 times a day dose can be gradually increased up to 150 mg / day.
Maintenance dose: 50 - 100 mg / day
Maximum daily dose: 300 mg
Prophylaxis of migraine: 10 mg at bed time. Dose can be gradually increased up to 100 mg.
Children:
Nocturnal enuresis
Children 12 - 16 years: 25 - 50mg to be taken 1 hour before bed time
Schedule of Amitriptyline
H
Storage Requirements for Amitriptyline
Store at room temperature in a tightly closed container. Protect from light. Keep out of the reach of children.
Effects of Missed Dosage of Amitriptyline
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 Amitriptyline
Give supportive measures and treatment. Remove the drug from the body by inducing emesis and gastric lavage. Activated charcoal can be given to reduce the absorption of the drug. Seizure can be treated with Diazepam or Phenytoin, arrhythmia with Lidocaine, and acidosis with Sodium bicarbonate.

Home Delivery for Amitriptyline in Your City

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

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

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