II. Preparations: Tricyclic Antidepressants - First generation (Tertiary amines)
-
General
- Greater Analgesic properties than second generation
- Agents
- Amitriptyline (Elavil, Endep)
- Clomipramine (Anafranil)
- Imipramine (Tofranil)
- Trimipramine (Surmontil)
- Doxepin (Sinequan, Adapin)
III. Preparations: Tricyclic Antidepressants - Second generation (Secondary amines)
-
General
- Less adverse effects than first generation
- Agents
- Nortriptyline (Pamelor, Aventyl)
- Desipramine (Norpramin)
- Protriptyline (Vivactil)
IV. Preparations: Tetracyclic Antidepressants (rarely used)
- Maprotiline (Ludiomil)
- Increased seizure Incidence
- Amoxapine (Asendin)
- Severe Extrapyramidal Side Effects
V. Adverse Effects
-
General
- Unable to tolerate full dose: 80%
- Medication discontinued due to adverse effects: 30%
- Secondary amines are much better tolerated
- Anticholinergic Symptoms
-
Antihistaminergic effects
- Sedation (limits use)
- Weight gain
- Serotoninergic Effects
- Cardiovascular effects: Orthostatic Hypotension
- Pro-Arrhythmic Effects (Class I Antiarrhythmic type)
- Sinus Tachycardia
- Supraventricular Tachycardia
- Ventricular Tachycardia
- Ventricular Fibrillation
- Prolongation of PR, QRS or QT Interval
- ST Segment and T Wave changes
- Bundle Branch Block or complete Heart Block
-
Antidepressant Withdrawal
- Prevent by tapering gradually, even over months
VI. Drug Interactions: Cardiovascular
- Absolute Contraindications
- Clonidine (Hypotension)
- Class I Antiarrhythmics (e.g. Quinidine, Flecainide)
- Prolonged QT Interval
- Other interactions
- Coumadin (increases ProTime)
- Aspirin (increases Tricyclic Antidepressant level)
- Fluoxetine (increases Tricyclic Antidepressant level)
VII. Precautions: Overdosage effects
- See Tricyclic Antidepressant Overdose
- Cardiotoxicity
- Death