Country: South Africa
Language: English
Source: South African Health Products Regulatory Authority (SAHPRA)
Lundbeck
SAROTEN® RETARD 25 mg Capsules SAROTEN® RETARD 50 mg Capsules SCHEDULING STATUS: S5 PROPRIETARY NAME (and dosage form): SAROTEN ® RETARD 25 mg Capsules SAROTEN ® RETARD 50 mg Capsules COMPOSITION: Each capsule contains amitriptyline hydrochloride in a sustained release formulation corresponding to 25 mg or 50 mg amitriptyline. PHARMACOLOGICAL CLASSIFICATION: A 1.2 Psychoanaleptics (antidepressants) PHARMACOLOGICAL ACTION: Amitriptyline is a tricyclic antidepressant. Amitriptyline inhibits serotonin and noradrenaline uptake equally. It has anticholinergic, antihistaminergic and sedative properties and it potentiates the effects of catecholamines. The antidepressive, mood-elevating effect usually sets in after 2-4 weeks, the sedative action is not delayed. Pharmacokinetics Amitriptyline as such is rapidly absorbed but owing to the sustained release from SAROTEN RETARD capsules amitriptyline only becomes available for absorption slowly. This results in a rather flat serum concentration curve. As SAROTEN RETARD is administered in the evening 3-4 hours before bedtime the highest serum concentrations of amitriptyline are present in the early hours of the morning owing to the slow absorption rate of this formulation. The bioavailability after an oral dose of amitriptyline is about 40% (first pass metabolism). The volume of distribution is about 22 L/kg. The plasma protein binding is about 95%. The biological half-life is 12-24 hours and clearance about 0,7 L/min. Amitriptyline is metabolised by N-demethylation, 10-hydroxylation and N-oxidation. The active substance, nortriptyline, is formed by demethylation. The therapeutic serum level (the sum of amitriptyline and nortriptyline) is 100- 250 ng/mL corresponding to 360-900 nmol/L. Amitriptyline and nortriptyline cross the placental barrier and a Read the complete document