May 25, 2006 -- Doctors from the CDC estimate that more than 3,000 people visited hospital emergency departments in 2004 due to side effects from drugs to treat attention deficit hyperactivity disorder (ADHD).
The estimate -- made by the CDC's Adam Cohen, MD, MPH, and colleagues -- appears in a letter in The New England Journal of Medicine.
Cohen and colleagues reviewed database records from 64 U.S. hospitals. They counted emergency department visits linked to stimulant drugs widely prescribed for ADHD.
The database showed 81 cases in 2004. From that figure, "we estimate that 3,075 patients presented to emergency departments nationally for adverse events from stimulant drugs prescribed for the treatment of ADHD" in 2004, write Cohen and colleagues.
Their letter doesn't tie any particular ADHD drug to the cases reported in the database.
Cohen and colleagues checked the database's records for Aug. 1, 2003 to Dec. 31, 2005. They found 188 emergency department visits related to ADHD drugs during that time.
Of those ER trips, more than half -- 115 -- were due to accidental ingestion or overdose, and half of those visits (65) were related to the patient taking medications that were not prescribed for them. Another 73 ER visits were due to adverse effects or allergic reactions.
Twenty-six patients -- including nine who had unintentionally taken the drugs or overdosed on the medications -- had possible cardiovascular symptoms or signs such as chest pain, high blood pressure, stroke, and irregular heartbeat.
Out of all 188 adverse events, 30 required hospitalization and 36 required pumping the patients' stomach. Most of those cases were linked to inappropriate use of the drugs.
All of the patients who had their stomachs pumped had overdosed on the drugs or unintentionally taken the drugs. All but six hospitalizations were due to overdoses or accidental ingestion of the drugs.
More than eight in 10 ER trips were made by patients less than 18 years old; more than half (59%) were made by males, who outnumber females in ADHD diagnoses.
Drug Company Responds
WebMD contacted the drug company Novartis, which makes the ADHD drug Ritalin, for its comments. Novartis spokeswoman Denise Brashear e-mailed the company's response.
"Regarding emergency room visits due to overdoses and misuse of ADHD medications reported by the CDC, when used inappropriately all medications have unpredictable effects. ADHD medications should only be used as indicated under the care of a qualified physician," the statement continues.
"Ritalin, approved by the FDA in December 1955, has a long record as a safe and effective medication for the symptoms of ADHD. For more than 50 years it has helped patients and their families lead more productive, healthy lives," states Novartis.
Estimates Too Low?
Cohen and colleagues note that ER estimates may be too low because some cases may not have been recorded in the database or may be difficult to diagnose in an emergency department.
"Nevertheless, we found that visits to an emergency department for adverse drug events due to stimulant medications are not uncommon," they write.
Cohen's team adds that doctors "should recognize that unintentional overdoses of stimulant medications are an important cause of injury to patients, and they should investigate cardiovascular symptoms of potential concern among patients taking stimulant medications." Doctors should also report serious adverse events to the FDA, note Cohen and colleagues.
Debate Over Possible 'Black Box' Warning
That recommendation touched off a flurry of doctors' letters published in The New England Journal of Medicine.
In a joint letter to the journal, Thomas Anders, MD, of the American Academy of Child and Adolescent Psychiatry and Steven Sharfstein, MD, of the American Psychiatric Association write that they are "concerned that such a warning will discourage patients and their families from using effective treatment.
"Untreated ADHD is associated with an elevated risk of substance abuse, academic failure, and motor vehicle accidents and an increased rate of psychiatric disorders," write Anders and Sharfstein.
Novartis, in its statement emailed to WebMD, commented on the journal letters: "Novartis fully supports the FDA's efforts to ensure that safety information in product labels for all ADHD medications is as clear as possible."
The journal also includes a letter by Steven Nissen, MD. He works at The Cleveland Clinic and was a consultant to the FDA's Drug Safety and Risk Management Advisory Committee for the hearings on ADHD drugs. In his letter to the journal, Nissen writes that he "strongly disagrees" with the idea that warnings about cardiovascular risks would discourage patients from receiving treatment.
"I cannot accept the paternalistic notion that patients and caregivers would be better off without information about drug risks," Nissen writes. "The presence of a black-box warning and a mandatory patient guide would probably stimulate useful discussions among patients, parents, and physicians about risks, benefits, and alternative therapies," he continues.