Methamphetamine HCl (Desoxyephedrine HCl)

 Action Activates noradrenergic neurons causing CNS and respiratory stimulation; timulates the satiety center in the brain causing appetite suppression.

 Indications Treatment of attention deficit disorder in children; short-term exogenous obesity adjunct.

 Contraindications Advanced arteriosclerosis; symptomatic cardiovascular disease; moderate to severe hypertension; hyperthyroidism; hypersensitivity to sympathomimetic amines; glaucoma; agitated states; history of drug abuse. Drug should not be used concomitantly with or within 14 days of MAO inhibitor use.

 Route/Dosage

Attention Deficit Disorder

CHILDREN: PO 5 mg 1–2 times/day; may be increased weekly by 5 mg to maximum of 20–25 mg/day in divided doses. Long-acting form: Once daily.

Exogenous Obesity

ADULTS & CHILDREN > 12 YR: PO 5 mg 1–3 times/day 30 min before meals. Long-acting form: 10–15 mg in AM. Not to be used beyond a few weeks.

 Interactions

Guanethidine: Amphetamines may decrease effectiveness. MAO inhibitors, furazolidone: Hypertensive crisis and intracranial hemorrhage may occur. Tricyclic antidepressants: Decreased amphetamine effect. Urinary acidifiers: Decreased amphetamine levels. Urinary alkalinizers: Increased amphetamine levels.

 Lab Test Interferences Plasma and urinary steroid levels may be altered.

 Adverse Reactions

CV: Palpitations; tachycardia; hypertension; arrhythmias. CNS: Hyperactivity; dizziness; insomnia; euphoria; restlessness; tremors; eadache. GI: Dry mouth; unpleasant taste; diarrhea; constipation; anorexia. GU: Impotence. DERM: Urticaria.

 Precautions

Pregnancy: Category C. Lactation: Excreted in breast milk. Children: Not recommended as anorectic agent in children < 12 yr. Drug dependence: Has high potential for dependence and abuse. Tolerance may occur; recommended dose should not be exceeded. Tartrazine sensitivity: Some products contain tartrazine, which may cause allergic reactions in susceptible individuals.

 Administration/Storage

• Administer last dose several hours before bedtime.
• Store in tightly closed container at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note cardiovascular disease, hyperthyroidism, glaucoma or sensitivity to sympathomimetic drugs.
• Take vital signs and auscultate heart and lungs before administration; monitor closely during treatment.
• Assess mental status: mood, sensorium, affect, stimulation, insomnia, aggressiveness. Depressed patients are more likely to misuse drug to induce euphoria and mood elevation.
• Monitor renal function.
• Monitor blood glucose level closely in diabetic patient. Changes in appetite and food intake will occur.
• Monitor for weight loss (may be desired effect).
• If hypertension, dysrhythmias, marked agitation, restlessness or confusion occur, withhold medication and notify physician.

 Patient/Family Education

• Instruct patient to take medication exactly as ordered and not to increase dosage unless advised by physician.
• Advise patient to take sips of water frequently, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs.
• Instruct patient to report excessive dryness of mouth, constipation or prolonged insomnia as dosage may need to be adjusted.
• Tell patient to avoid caffeine, which increases drug effect.
• Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness or coordination.
• Instruct patient not to take otc medications without consulting physician.
• Tell parents to report decreased appetite to pediatrician.