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Author: Admin | 2025-04-28
For clinical features. Check urea and electrolytes—look for low potassium and monitor urine output. Check arterial blood gases—look for acidosis. Perform electrocardiograph - look for QRS>0.16 seconds 4. Do not give flumazenil to reverse benzodiazepine toxicity in mixed overdoses. 5. Consider gastric lavage only if within one hour of a potentially fatal overdose. 6. Give 50 g of charcoal if within one hour of ingestion. 7. Patency of the airway is maintained by intubation, where required. Treatment in respirator is advised to prevent a possible respiratory arrest. Continuous ECG-monitoring of cardiac function for 3-5 days. Treatment of the following will be decided on a case by case basis: - Wide QRS-intervals, cardiac failure and ventricular arrhythmias - Circulatory failure - Hypotension - Hyperthermia - Convulsions - Metabolic acidosis. 8. Unrest and convulsions may be treated with diazepam. 9. Patients who display signs of toxicity should be monitored for a minimum of 12 hours. 10. Monitor for rhabdomyolysis if the patient has been unconscious for a considerable time. 11. Since over dosage is often deliberate, patients may attempt suicide by other means during the recovery phase. Deaths by deliberate or accidental over dosage have occurred with this class of medicament. 5. Pharmacological properties 5.1 Pharmacodynamic properties Pharmacotherapeutic group: Antidepressants - Non-selective monoamine reuptake inhibitor (tricyclic antidepressant) ATC-Code: N06AA09 Mechanism of action Amitriptyline is a tricyclic antidepressant and an analgesic. It has marked anticholinergic and sedative properties. It prevents the re-uptake, and hence the inactivation of noradrenaline and serotonin at nerve terminals. Reuptake prevention of these monoamine neurotransmitters potentiate their action in the brain. This appears to be associated with the antidepressant activity. The mechanism of action also includes ion-channel blocking effects on sodium, potassium and NMDA channel at both central and spinal cord level. The noradrenaline, sodium and the NMDA effects are mechanisms known to be involved in the maintenance of neuropathic pain, chronic tension type headache prophylaxis and migraine prophylaxis. The pain-reducing effect of amitriptyline is not linked to its anti-depressive properties. Tricyclic antidepressants possess affinity for muscarinic and histamine H1 receptors to varying degrees. Clinical efficacy and safety The efficacy and safety of amitriptyline has been demonstrated in treatments of the following indications in adults: • Major Depressive Disorder • Neuropathic Pain • Chronic tension type headache prophylaxis • Migraine prophylaxis The efficacy and safety of amitriptyline has been demonstrated for treatments of nocturnal enuresis in children aged 6 years and above (see section 4.1). The recommended doses are provided in section 4.2. For treatment of depression, doses of up to 200 mg daily and, occasionally, up to 300 mg daily have been used in severely depressed patients in hospital. The antidepressant and analgesic effects usually set in after
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