The FDA said Actavis Totowa LLC, formerly known as Amide Pharmaceutical Inc. of Totowa, N.J., reported some tablets may be double the appropriate thickness and contain twice the approved level of active ingredient.

The products are distributed by Mylan Pharmaceuticals Inc. under a "Bertek" label and by UDL Laboratories Inc. under a "UDL" label.

Digitek is used to treat heart failure and abnormal heart rhythms. The existence of double-strength tablets poses a risk of digitalis toxicity in patients with renal failure and can cause nausea, vomiting, dizziness, low blood pressure, cardiac instability and bradycardia. Death can also result from excessive Digitalis intake.

Customers with questions can call 888-276-6166.

The FDA said any adverse reactions experienced with the use of the product should also be reported to the its MedWatch Program at 800-332-1088.