What happens when a patient overdoses on a tricyclic antidepressant?
Tricyclic antidepressant overdose is poisoning caused by excessive medication of the tricyclic antidepressant (TCA) type. Symptoms may include elevated body temperature, blurred vision, dilated pupils, sleepiness, confusion, seizures, rapid heart rate, and cardiac arrest.
Why do TCA cause respiratory depression?
The amount of unbound tricyclic may also increase if the overdose causes respiratory depression resulting in an acidosis, which reduces protein binding. The toxic effects of tricyclics are caused by four main pharmacological properties: Inhibition of norepinephrine reuptake at nerve terminals.
Can amitriptyline cause respiratory problems?
Amitriptyline was studied in greater detail and caused a dose-related (0.01-1.0 mM) reduction in ventilation and perfusion flow. At the highest drug concentration pronounced lung edema was observed.
What is the mechanism of action for tricyclic antidepressants?
Mechanism of Action Tricyclic antidepressants act on approximately five different neurotransmitter pathways to achieve their effects. They block the reuptake of serotonin and norepinephrine in presynaptic terminals, which leads to increased concentration of these neurotransmitters in the synaptic cleft.
How do you manage an overdose of tricyclic antidepressants?
Administration of sodium bicarbonate might be beneficial for patients with severe or life-threatening TCA toxicity if a prehospital protocol exists for its use (Grades B/D). Benzodiazepines are recommended for TCA-associated convulsions (Grade D).
What is the mechanism of action of amitriptyline?
Mechanism of Action Amitriptyline increases noradrenergic or serotonergic neurotransmission by blocking the norepinephrine or serotonin transporter (NET or SERT) at presynaptic terminals.
How do you treat a tricyclic antidepressant overdose?
What is are the main mechanisms of action of antidepressant medications?
The main hypothesis regarding the mechanism of action of antidepressant drugs is monoaminergic and mainly involves two neurotransmitters, serotonin and noradrenaline. Despite the well-recognized therapeutic efficacy of selective serotonin reuptake inhibitors (SSRIs), some disadvantages still occur.
What are the precautions and contraindications for the tricyclic antidepressants?
Ask your doctor before taking TCAs if you:
- Are under age 25 or over age 65.
- Have diabetes, heart problems, or a thyroid disorder.
- Have any conditions affecting your urinary tract or an enlarged prostate.
- Have glaucoma.
- Have a liver disease.
- Have a history of seizures.
- Take medications to help manage your mood.
What is the mechanism of action of antidepressant medications?
The antidepressants inhibit reuptake of neurotransmitters through selective receptors thereby increasing the concentration of specific neurotransmitter around the nerves in the brain. One of such antidepressant is selective serotonin reuptake inhibitor (SSRI), which affects the brain serotonin level.
What is a tricyclic antidepressant overdose?
Tricyclic antidepressant overdose: a review Overdoses of tricyclic antidepressants are among the commonest causes of drug poisoning seen in accident and emergency departments. This review discusses the pharmacokinetics, clinical presentation and treatment of tricyclic overdose.
What are tricyclic antidepressants (TCAs)?
Introduction Tricyclic antidepressants (TCAs) were introduced in the late 1950s for the treatment of depression.
What is the main cause of antidepressant overdose?
Tricyclic antidepressants (TCAs) are the main cause of damaging antidepressant overdose because, unlike other antidepressants, they have a narrow therapeutic range and become potent cardiovascular and central nervous system toxins in moderate doses.
What are the clinical features of tricyclic overdose (TCO)?
The clinical features of tricyclic overdose can be grouped according to their effects on the peripheral autonomic system (anticholinergic effects), the cardiovascular system and the central nervous system (table 1). Anticholinergic features are common and may aid diagnosis in certain patients.