Home Drug Guide Dexmethylphenidate Hydrochloride

Drug Guide

Generic Name

Dexmethylphenidate Hydrochloride

Brand Names Focalin, Focalin XR

Classification

Therapeutic: Central Nervous System Stimulant for ADHD

Pharmacological: Methylphenidate derivative; Psycho-stimulant

FDA Approved Indications

Attention deficit hyperactivity disorder (ADHD)

Mechanism of Action

Dexmethylphenidate increases synaptic concentrations of dopamine and norepinephrine by inhibiting their reuptake, leading to enhanced neurotransmission in the central nervous system.

Dosage and Administration

Adult: Start with 10 mg twice daily (before breakfast and lunch). Titrate in 5-10 mg increments weekly to effective dose, not exceeding 20 mg twice daily.

Pediatric: Initial dose usually 5 mg BID; titrate cautiously. Max dose typically 20 mg BID.

Geriatric: Use with caution; start at lower doses due to potential for increased sensitivity and comorbidities.

Renal Impairment: Adjust dose based on severity; consult specific guidelines.

Hepatic Impairment: Use with caution; no specific adjustments well-established.

Pharmacokinetics

Absorption: Rapidly absorbed; peak plasma concentration achieved in 1-3 hours.

Distribution: Widely distributed, crosses blood-brain barrier.

Metabolism: Extensively metabolized in the liver, mainly via de-esterification.

Excretion: Primarily excreted in urine as metabolites; minor unchanged drug.

Half Life: Approx. 3-4 hours for immediate-release; XR formulation designed for 8-12 hours duration.

Contraindications

Known hypersensitivity to methylphenidate or other stimulants.
Use in patients with marked anxiety, tension, or agitation.
Glaucoma.
Use with or within 14 days of MAO inhibitors.

Precautions

Monitor for new or worsening psychiatric symptoms.
Assess cardiovascular health before initiation.
Use cautiously in patients with a history of drug abuse, motor tics, or Tourette’s disorder.

Adverse Reactions - Common

Insomnia (Common)
Decreased appetite (Common)
Stomach ache (Common)
Headache (Common)

Adverse Reactions - Serious

Cardiovascular events (e.g., sudden death, arrhythmias) (Rare)
Psychosis or new/worsening behavior (Rare)
Growth suppression in children (Controversial, monitor height/weight)

Drug-Drug Interactions

Monoamine oxidase inhibitors (risk of hypertensive crisis)
Alkalinizing agents (may increase absorption)
Other CNS stimulants

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor weight, height in children, growth, BP, heart rate, and mental health status.

Diagnoses:

Risk for hypertension
Impaired child growth
Risk of dependence

Implementation: Administer doses on a regular schedule, preferably before meals.

Evaluation: Assess efficacy via ADHD symptom reduction and monitor for adverse effects.

Patient/Family Teaching

Take medication exactly as prescribed.
Report any chest pain, palpitations, or psychiatric changes.
Monitor for appetite changes and growth in children.
Avoid alcohol and other CNS depressants.

Special Considerations

Black Box Warnings:

Potential for abuse and dependence.
Sudden death and cardiovascular risks in children and adolescents with underlying structural cardiac abnormalities.

Genetic Factors: Genetic polymorphisms may influence metabolism and response.

Lab Test Interference: May interfere with growth measurements and some laboratory tests.

Overdose Management

Signs/Symptoms: Restlessness, tremors, hyperreflexia, hallucinations, cardiac arrhythmias, seizures.

Treatment: Provide supportive care, activated charcoal if recent ingestion, benzodiazepines for seizures, and cardiovascular support as needed.

Storage and Handling

Storage: Store at room temperature, away from light and moisture.

Stability: Stable for specified shelf life as per manufacturer instructions.