The drug, known by the brand name Klonopin, is used for panic disorder and seizures.
The maker of clonazepam, a drug commonly prescribed for anxiety and seizures, has expanded its recall of some of the pills after it discovered that they were labeled with the wrong strength, the Food and Drug Administration announced this week.
The drug’s maker, Endo, recalled 16 product lots of clonazepam, a drug best known by the brand name Klonopin. The company said it had not received any reports of adverse events related to the recall.
Clonazepam is among a class of psychiatric drugs called benzodiazepines, which slow brain activity and can cause sedation or calming effects.
The agency warned that adults and children who inadvertently took a higher dose of clonazepam than prescribed could experience side effects, including “significant” sedation, confusion, dizziness, diminished reflexes, the loss of muscle control and muscle weakness.
An overdose can also lead to other serious issues, including “significant, possibly life-threatening, respiratory depression” for patients who have pulmonary disease or for those who are already taking a near-maximum dose of the drug. People who take other medications that cause respiratory depression are also at risk of this, the agency said.
In a statement, Endo said the recall followed an internal quality investigation that identified a potential label problem with a third-party vendor. “Our first priority at Endo is the quality and safety of our products and well-being of patients,” a representative said.
The company first announced in July that it would recall one lot of the medication.
The drug is packaged in cartons containing tablets packed into blister strips; the F.D.A. said these strips reflect the correct product strength. The packaging uses the name Par Pharmaceutical, which marketed clonazepam before Endo acquired it, the F.D.A. said
The number of patients the expanded recall would affect was not immediately clear, but the F.D.A. said that anyone taking clonazepam from the recalled lots should stop and contact a doctor.
In 2020, the F.D.A. began requiring that packages of clonazepam and other benzodiazepines include a prominent warning about the risk of abuse, addiction and physical withdrawal symptoms.
In announcing the change, the agency also asked doctors to be more careful in prescribing benzodiazepines with opioids or other drugs that depress the central nervous system.