Drug Guide
Desipramine Hydrochloride
Classification
Therapeutic: Antidepressant, Tricyclic
Pharmacological: Tricyclic Antidepressant (TCA)
FDA Approved Indications
- Major depressive disorder
Mechanism of Action
Inhibits the reuptake of norepinephrine and serotonin, increasing their levels in the central nervous system, resulting in antidepressant effects.
Dosage and Administration
Adult: Typically, starting dose is 50-75 mg at bedtime, titrated up as needed, usual range 100-200 mg/day.
Pediatric: Use is generally not recommended in children and adolescents due to safety concerns.
Geriatric: Start with lower doses (e.g., 25 mg at bedtime) and titrate slowly, considering increased sensitivity and risk of side effects.
Renal Impairment: Use with caution; monitor and consider dose adjustments as renal function declines.
Hepatic Impairment: Use with caution; dose reduction may be necessary due to impaired metabolism.
Pharmacokinetics
Absorption: Well absorbed orally, with variable bioavailability.
Distribution: Widely distributed; crosses the blood-brain barrier and placenta.
Metabolism: Primarily hepatic via CYP2D6 to active metabolites and other pathways.
Excretion: Excreted mainly in urine.
Half Life: Approximately 12-24 hours, allowing for once or twice daily dosing.
Contraindications
- Recent myocardial infarction
- Use within 14 days of monoamine oxidase inhibitors (MAOIs)
- Known hypersensitivity
Precautions
- History of seizure disorder
- Glaucoma
- Urinary retention
- Suicidality risk, especially in young adults
- Elderly patients may be more susceptible to side effects
Adverse Reactions - Common
- Dry mouth (Common)
- Drowsiness (Common)
- Dizziness (Common)
- Constipation (Common)
Adverse Reactions - Serious
- Cardiac arrhythmias (Serious, potentially life-threatening)
- Seizures (Serious)
- Hypotension (Serious)
Drug-Drug Interactions
- MAO inhibitors – risk of serotonin syndrome and hypertensive crisis
- Other CNS depressants – increased sedation
- Anticholinergic agents – additive anticholinergic effects
Drug-Food Interactions
- Alcohol – additive CNS depression and cardiovascular effects
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor heart rhythm via ECG, assess mental status and suicidality, monitor for anticholinergic effects.
Diagnoses:
- Risk for cardiac arrhythmias
- Risk for falls related to dizziness
- Altered mental status
Implementation: Administer at bedtime to reduce sedation; instruct patient to avoid abrupt discontinuation; monitor for side effects.
Evaluation: Assess for therapeutic response and adverse effects; re-evaluate dosing as needed.
Patient/Family Teaching
- Take medication exactly as prescribed; do not stop abruptly.
- Report signs of cardiac issues, suicidal thoughts, or severe side effects.
- Avoid alcohol and other CNS depressants.
- Be aware of anticholinergic side effects like dry mouth and constipation.
Special Considerations
Black Box Warnings:
- Increased risk of suicidality in children, adolescents, and young adults.
Genetic Factors: Metabolism via CYP2D6; poor metabolizers may have increased plasma levels.
Lab Test Interference: May affect blood glucose monitoring and certain cardiac assessments.
Overdose Management
Signs/Symptoms: Confusion, agitation, hallucinations, seizures, cardiac arrhythmias, coma.
Treatment: Supportive care, activated charcoal if recent ingestion, sodium bicarbonate for cardiac arrhythmias, and emergency resuscitation as needed.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F), away from light and moisture.
Stability: Stable under recommended storage conditions; check expiration date regularly.