Alliant Pharmaceuticals expanded its nationwide recall of Methylin Chewable Tablets to cover all lots of the drug. Methylin is prescribed to treat attention deficit hyperactivity disorder, also known as ADHD. Methylin is also prescribed to treat narcolepsy. Further investigation by the manufacturer, Malinckrodt, Inc., of St. Louis, MO, found that tablets of all dosage strengths may contain as much as three times the amount of active ingredient necessary.

The drug maker blamed the problem on a mixing issue. The recalled medication came in 100-tablet bottles with the following lot numbers:

2.5-mg dose

• AMT20401A
• AMT20402A
• AMT20403A
• AMT20404A

5-mg dose

• AMT50401A
• AMT50402A
• AMT50403A
• AMT50404A

10-mg dose

• AMT100401A
• AMT100402A
• AMT100403A
• AMT100404A

Alliant said fewer than half of the approximately 10,000 bottles manufactured have been distributed. Alliant is sending letters to wholesalers and pharmacists to quarantine any bottles that match the above lot numbers and notify patients who received the prescription. More information can be obtained by calling Alliant at 1-770-817-4500 between 8 am and 5pm EST, Monday through Friday.