Summary Safety Review - Methylphenidate - Priapism

Review decision

A Summary Safety Review complements other safety related information to help Canadians make informed decisions about their use of health products. Each summary outlines what was assessed in Health Canada’s review, what was found and what action was taken by Health Canada, if any.


Issued: 2015-04-21

Product

Methylphenidate

Potential Safety Issue

Priapism

Key Messages

  • Methylphenidate products are used for the treatment of attention-deficit hyperactivity disorder (ADHD) in adults and children 6 years of age and over.
  • A safety review was initiated following the actions by the United States Food and Drug Administration (FDA) indicating that all methylphenidate product labels and patient Medication Guides be updated to include information about the risk of priapism. Priapism (prolonged and painful erection) is a rare but serious adverse reaction.
  • The Canadian prescribing information for all brand name and generic methylphenidate products will be updated to include the risk of priapism.

Overview

A safety review was initiated to evaluate the available information regarding the potential risk of priapism associated with the use of methylphenidate products in the treatment of attention-deficit hyperactivity disorder (ADHD). Priapism is a prolonged and usually painful erection of the penis; it is considered a medical emergency. This review was prompted by actions by the United States Food and Drug Administration (FDA) indicating that all methylphenidate product labels and patient Medication Guides be updated to include information about the risk of priapism.

Use in Canada

  • Methylphenidate is marketed under the brand names of BIPHENTIN, CONCERTA, RITALIN and RITALIN SR, and 16 generic methylphenidate products currently available in Canada.
  • Methylphenidate products are used for the treatment of ADHD in adults and children 6 years of age and over.

Safety Review Findings

  • Priapism is rare. It is a serious medical condition that requires immediate medical attention to prevent possible long-term effects on the penis.Drugs are a known cause.
  • At the time of this review, Health Canada had received one report of priapism associated with the use of methylphenidate.a  b A description of this case was published in the Canadian Adverse Reaction Newsletter in July 2006
  • There were a small number of cases of priapism in association with methylphenidate products reported internationally and in the literature. In nearly half of these cases, methylphenidate products were found to be the probable cause of priapism.
  • Priapism has been reported during treatment with methylphenidate products after increasing the dose or stopping the product even for a short period of time.

Conclusions and actions

  • Although there was only one report of priapism associated with methylphenidate in Canada, Health Canada's actions take into account the international experience with this rare, but serious adverse reaction.
  • There is limited but good quality evidence of a possible association between priapism and the use of methylphenidate products.
  • The Canadian prescribing information for all brand name and generic methylphenidate products will be updated to include the very rare risk of priapism.
  • Health Canada issued a communication to inform healthcare professionals and patients about the possibility of priapism associated with the use of methylphenidate products.
  • Health Canada will continue to monitor and evaluate the risk of priapism associated with the use of methylphenidate products. Health Canada will keep Canadians informed and take action, as appropriate, if any new safety information is identified

Additional information

The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this drug both in Canada and internationally.

For additional information, contact the Marketed Health Products Directorate.

Footnotes

  1. Canadian reports can be accessed through the Canada Vigilance Adverse Reaction Database.
  2. Since the completion of the Safety Review, an additional case has been received by Health Canada.

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