Amitriptyline (HCl)
Amitriptyline (HCl) is a prototype drug of tricyclic antidepressants. It has characteristic three ring nucleus. Tricyclic antidepressant has been used for almost four decades. Chemically Amitriptyline (HCl) is closely related to the phenothiazines.it also has sedative and anxiolytic properties.
Primary Characteristics
Amitriptyline (HCl) is also known as Amitriptyline.
It is of Synthetic origin and belongs to Dibenzo cyclohepten propylamine.
It belongs to Adenosine uptake inhibitor pharmacological group on the basis of mechanism of action and also classified in Antidepressant pharmacological group. It is also classified under Psychotherapeutic Drugs .
Molecular Weight: 313.9 · pKa: 9.4 · Solubility in Water: 1 in 1 · Solubility in Alcohol: 1 in 1.5 · Non-proprietary name: Amitriptyline (HCl).
Pharmacokinetics
Absorption: Amitriptyline (HCl) has an oral bioavailability is 97% (±2%), pre-systemic (first-pass) metabolism accounts for 52.5% (±14.5%).
Distribution: Amitriptyline (HCl) has a volume of distribution is 11-18 l/kg. plasma protein binding is 95%.
Elimination: it is metabolised via Hepatic (extensively), plasma half-life is 10-28 hr, renal excretion is major.
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Indications
Amitriptyline (HCl) is primarily indicated in conditions like Chronic pain, Depression, Enuresis, Migraine prophylaxis, Tension headache.
Contraindications
Amitriptyline (HCl) is contraindicated in conditions like Glucoma, Myocardial infarction, Prostatic hypertrophy.
Dosage
Amitriptyline (HCl)'s dosage details are as follows:
| Dose | Single Dose | Frequency | Route | Instructions |
|---|---|---|---|---|
| Adult Dosage | ||||
| 0.356 mg/ kg | 0.356 mg/ kg | Every 6h | IM | Initial |
| 1.428 mg/ kg | 1.428 mg/ kg | Every 24h | IM | Maintenance for 6 Months |
| 75 mg | 75 mg | Every 24h | PO | At bedtime, increased gradually to 150 mg/day. |
| Paediatric Dosage (20kg) | ||||
| 0.6 mg/kg | 0.6 mg/kg | Every 24h | Oral | Recommended for 5-12 yrs Children |
| Neonatal Dosage (3kg) | ||||
| 0 – 0 | — | — | not recommended in this age group | |
Drug Interactions
Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Side Effects
Amitriptyline (HCl) in overdosage may give rise to further complications which include Tachycardia , Conduction disturbances , Postural hypotension , Cardiac arrhythmias, Congestive heart failure .
Amitriptyline (HCl) produces potentially life-threatening effects which include Agranulocytosis, Thrombocytopenia . Careful monitoring is needed with proper medical management.
The signs and symptoms that are produced after acute overdosage of Amitriptyline (HCl) are Hypotension, Coma, Mydriasis, QT interval lengthening, P-R interval lengthening, Urinary retention, Cardiac arrhythmias, Seizures, Blurred vision, Metabolic acidosis, Hypoxia, Dry mouth, Hypothermia, Sinus tachycardia.
Amitriptyline (HCl) is known to cause more or less tolerable side effects which are usually transient. These include Blurred vision, Constipation , Dizziness, Dry mouth, Fatigue, Headache, Tremor, Urinary retensionX, Weakness.
Warnings / Precautions
Interference in Pathology
Amitriptyline (HCl) may interfere in the diagnosis of Fringes TLC method of measuring Urinary Alkaloids .
Available Brands
Storage Conditions
Drug Classification
- 1.24.2.1 — Drugs used in depression