pemoline
Cylert, PemADD, PemADD CT

Available forms
Available by prescription only
Tablets: 18.75 mg, 37.5 mg, 75 mg
Tablets (chewable and povidone-containing): 37.5 mg

Indications and dosages
 Attention deficit hyperactivity disorder (ADHD). Children age 6 and older: Initially, 37.5 mg P.O. in the morning. Daily dosage can be increased by 18.75 mg weekly. Effective dosage range is 56.25 to 75 mg daily. Maximum, 112.5 mg daily.
 Note: Because of its association with life-threatening hepatic failure, pemoline shouldn’t be considered first-line therapy for ADHD.
 Narcolepsy ◇. Adults: 50 to 200 mg daily, in divided doses after breakfast and lunch.

Pharmacodynamics
Analeptic action: Differs structurally from methylphenidate and amphetamines; however, like those drugs, pemoline has a paradoxical calming effect in children with ADHD. Mechanism of action is unknown. May be mediated through dopaminergic mechanisms. CNS stimulant effect has been studied in narcolepsy in adults, in fatigue, in depressed and schizophrenic states, and in elderly patients.

Pharmacokinetics
Absorption: Well absorbed after oral administration.
Distribution: Drug is 50% protein-bound.
Metabolism: Metabolized by liver to active and inactive metabolites.
Excretion: 75% of drug and metabolites are excreted in urine within 24 hours. Half-life is 12 hours.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug, patients with idiosyncratic reactions to drug, and patients with hepatic dysfunction. Use cautiously in patients with impaired renal function.

Interactions
Drug-drug. Anticonvulsants: Decreases seizure threshold. Monitor patient closely.
Drug-food. Caffeine: Decreases efficacy of pemoline in ADHD. Discourage use together.

Adverse reactions
CNS: insomnia, dyskinetic movements, irritability, fatigue, mild depression, dizziness, headache, drowsiness, hallucinations, seizures, Tourette syndrome, abnormal oculomotor function.
GI: anorexia, abdominal pain, nausea.
Hematologic: aplastic anemia.
Hepatic: hepatic failure.
Skin: rash.

Effects on lab test results
• May increase liver enzyme and prostate-specific antigen levels.
• May decrease hemoglobin and hematocrit.

Overdose and treatment
Toxicity may cause irregular respiration, hyperreflexia, restlessness, tachycardia, hallucinations, excitement, and agitation.
 Treat overdose symptomatically and supportively. Use gastric lavage if symptoms aren’t severe. Monitor vital signs and fluid and electrolyte balance. Maintain patient in a cool room, monitor temperature, and minimize external stimulation; protect patient from self-injury. Chlorpromazine or haloperidol usually can reverse CNS stimulation. Hemodialysis may help.

Special considerations
• Give drug in a single morning dose for maximum daytime benefit and to minimize insomnia.
• Explain that therapeutic effects may not appear for 3 to 4 weeks and that intermittent drug-free periods when stress is least evident (weekends, school holidays) may help assess patient’s condition, prevent development of tolerance, and permit decreased dosage when drug is resumed.
• Abrupt withdrawal after high-dose long-term use may unmask severe depression. Lower dosage gradually to prevent acute rebound depression.
• Drug impairs ability to perform tasks requiring mental alertness.
• Make sure patient obtains adequate rest; fatigue may result as drug wears off.
• Discourage pemoline use for analeptic effect because drug has abuse potential; CNS stimulation superimposed on CNS depression may cause neuronal instability and seizures.
• Monitor start of therapy closely; drug may precipitate Tourette syndrome.
• Check vital signs regularly for increased blood pressure or other signs of excessive stimulation.
• Monitor blood and urine glucose levels in diabetic patients; drug may alter insulin requirements.
• Monitor CBC, differential, and platelet counts while patient receives long-term therapy.
• Determine baseline and reassess liver function tests every 2 weeks. If ALT level equals or exceeds the upper limit of normal, stop drug.
• Monitor height and weight; drug may cause growth suppression.
• Carefully follow manufacturer’s directions for reconstitution, storage, and administration of all preparations. Pemoline has been used to treat narcolepsy in adults (50 to 200 mg divided twice daily) as well as depression and schizophrenia, but these uses are controversial.
Pediatric patients
• Drug isn’t recommended for ADHD in children younger than age 6.

Patient education
• Explain rationale for therapy and anticipated risks and benefits; teach signs and symptoms of adverse reactions and need to report these.
• Tell patient to avoid drinks containing caffeine to prevent added CNS stimulation.
• Urge patient or parent not to alter dosage without medical approval.
• Warn against using drug to mask fatigue. Tell patient to obtain adequate rest and report excessive CNS stimulation.
• Advise diabetic patient to monitor blood glucose levels because drug may alter insulin needs.
• Advise patient to avoid tasks that require mental alertness until degree of sedative effect is determined.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use