British physicians are being warned by their country's medical authorities about new risks associated with atomoxetine in the treatment of attention-deficit hyperactivity disorder.
The new risks of seizures and abnormal heart rhythm (QT interval prolongation) were identified by the Medicines and Healthcare Products Regulatory Agency (MHRA), the U.K. equivalent of the Food and Drug Administration (FDA), after a Europewide review of atomoxetine, which is marketed in the United Kingdom and United States as Strattera.
The FDA has not issued similar warnings, although it is evaluating the U.K. data and “will make any necessary label changes as appropriate,” said spokesperson Crystal Rice.
The MHRA initiated its Europewide review of Strattera last fall, after new warnings were issued about the drug's potential to cause suicidal thoughts and behavior. Changes were made to the product's label at that time in the United Kingdom and the United States. The British review concluded that “the overall balance of risks and benefits of Strattera remains positive in the treatment of ADHD in children of 6 years and older and in adolescents.”
However the MHRA's letter to health care physicians says the product's label is being updated to reflect the new risks, and it offers the following new advice to prescribers:
▸ Seizures are a potential risk with Strattera and therefore it should be introduced with caution in patients with a history of seizure. Discontinuation of Strattera should be considered in any patient developing seizures or if there is an increase in seizure frequency.
▸ Reports of QT interval prolongation have been received in association with Strattera. Therefore it should be used with caution in those with congenital or acquired long QT or a family history of QT prolongation. This risk may be increased if Strattera is used concomitantly with other drugs that produce QT prolongation, drugs that can cause electrolyte disturbances, and those that inhibit cytochrome P450 2D6.
The new evidence comes on the heels of a recent FDA panel meeting in which reports of sudden death and nonfatal cardiovascular events in connection with ADHD drugs were discussed. Last month, the panel advised that ADHD drugs carry a black box warning about these potential adverse events.