Does Cylert (pemoline) cause side effects?

Cylert (pemoline) is a central nervous system stimulant used to treat attention deficit hyperactivity disorder (ADHD). Pemoline is structurally dissimilar to the amphetamines and methylphenidate. The brand name Cylert is no longer available in the U.S. Generic versions may be available.

Common side effects of Cylert include

Serious side effects of Cylert include life-threatening liver failure.

The interaction of Cylert with other drugs has not been studied in humans. 

There are no adequate and well-controlled studies of Cylert in pregnant women. Cylert should be used during pregnancy only if clearly needed. 

It is unknown if Cylert is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Cylert is administered to a breastfeeding woman.

What are the important side effects of Cylert (pemoline)?

Common side effects of Cylert (pemoline) include:


Because of its association with life-threatening hepatic failure, Cylert (pemoline) should not ordinarily be considered as first line drug therapy for ADHD.

  • Since Cylert (pemoline)´s marketing in 1975, 13 cases of acute hepatic failure have been reported to the FDA.
  • While the absolute number of reported cases is not large, the rate of reporting ranges from 4 to 17 times the rate expected in the general population.
  • This estimate may be conservative because of under-reporting and because the long latency between initiation of Cylert (pemoline) treatment and the occurrence of hepatic failure may limit recognition of the association.
  • If only a portion of actual cases were recognized and reported, the risk could be substantially higher.
  • Of the 13 cases reported as of May 1996, 11 resulted in death or liver transplantation, usually within four weeks of the onset of signs and symptoms of liver failure.
  • The earliest onset of hepatic abnormalities occurred six months after the initiation of Cylert (pemoline).
  • Although some reports described dark urine and nonspecific prodromal symptoms (e.g., anorexia, malaise, and gastrointestinal symptoms), in other reports it was not clear if any prodromal symptoms preceded the onset of jaundice.
  • It is also not clear if the recommended baseline and periodic liver function testing are predictive of these instances of acute liver failure.
  • Cylert (pemoline) should be discontinued if clinically significant hepatic dysfunction is observed during its use.

Cylert (pemoline) side effects list for healthcare professionals

The following are adverse reactions in decreasing order of severity within each category associated with Cylert (pemoline). 

Hepatic: There have been reports of hepatic dysfunction, ranging from asymptomatic reversible increases in liver enzymes to hepatitis, jaundice and life- threatening hepatic failure, in patients taking Cylert.

Hematopoietic: There have been isolated reports of aplastic anemia.

Central Nervous System: The following CNS effects have been reported with the use of Cylert (pemoline) : convulsive seizures: literature reports indicate that Cylert (pemoline) may precipitate attacks of Gilles de la Tourette syndrome; hallucinations; dyskinetic movements of the tongue, lips, face and extremities: abnorrnal oculomotor function including nystagmus and oculogyric crisis; mild depression; dizziness; increased irritability; headache; and drowsiness.

Insomnia is the most frequently reported side effect of Cylert (pemoline), it usually occurs early in therapy prior to an optimum therapeutic response. In the majority of cases it is transient in nature or responds to a reduction in dosage.

Gastrointestinal: Anorexia and weight loss may occur during the first weeks of therapy. In the majority of cases it is transient in nature; weight gain usually resumes within three to six months.

Nausea and stomach ache have also been reported.

Genitourinary: A case of elevated acid phosphatase in association with prostatic enlargement has been reported in a 63-year-old male who was treated with Cylert (pemoline) for sleepiness. The acid phosphatase normalized with discontinuation of Cylert (pemoline) and was again elevated with rechallenge.

Miscellaneous: Suppression of growth has been reported with the long- term use of stimulants in children. Skin rash has been reported with Cylert (pemoline). Mild adverse reactions appearing early during the course of treatment with Cylert (pemoline) often remit with continuing therapy. If adverse reactions are of a significant or protracted nature, dosage should be reduced or the drug discontinued.

What drugs interact with Cylert (pemoline)?

The interaction of Cylert (pemoline) with other drugs has not been studied in humans. Patients who are receiving Cylert (pemoline) concurrently with other drugs, especially drugs with CNS activity, should be monitored carefully.

Decreased seizure threshold has been reported in patients receiving Cylert (pemoline) concomitantly with antiepileptic medications.

Does Cylert (pemoline) cause addiction or withdrawal symptoms?


Controlled Substance: Cylert (pemoline) is subject to control under DEA schedule IV.

Abuse: Cylert (pemoline) failed to demonstrate a potential for self-administration in primates. However, the pharmacologic similarity of pemoline to other psychostimulants with known dependence liability suggests that psychological and/ or physical dependence might also occur with Cylert (pemoline).

There have been isolated reports of transient psychotic symptoms occurring in adults following the long-term misuse of excessive oral doses of pemoline.

Cylert (pemoline) should be given with caution to emotionally unstable patients who may increase the dosage on their own initiative.

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Medically Reviewed on 8/21/2020
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Professional side effects, drug interactions, and addiction sections courtesy of the U.S. Food and Drug Administration.