The FDA is warning the public that methylphenidate products may cause priapism. 

Priapism is a prolonged and sometimes painful erection. Methylphenidate is a type of central nervous system stimulant used to treat attention hyperactivity disorder (ADHD).

RELATED: Psychiatric Disorders Resource Center

Affected drugs include: Concerta (Janssen), Daytrana, Focalin/Focalin XR (Novartis), Metadate CD/Metadate ER (UCB), Methylin/Methylin ER (Shionogi), Quillivant XR (Pfizer), and Ritalin/Ritalin LA/Ritalin SR (Novartis). 

The drug labels and patient Medication Guides have been updated to include information about this rare but serious warning of priapism.

SEE ALSO: Medications for ADHD

Healthcare professionals are recommended to talk to male patients and caregivers about the signs and symptoms of priapism and emphasize the need for immediate treatment if it occurs.

For more information call (888) 463-6332 or visit the FDA MedWatch page