There was an error in the July/August 2007 issue of Home Healthcare Nurse (Volume 25, No. 7) on page 452. Under the heading "Dietary Considerations" it is stated in the first paragraph that "[horizontal ellipsis] vitamin K may antagonize (amplify or increase) the anticoagulant effect" of warfarin. Please see correction with further explanation below:

Vitamin K decreases the effects of warfarin. Vitamin K is used as an antidote for overdoses of warfarin; however, the patient should not drastically change his or her current dietary intake of foods such as spinach, kale, green leafy lettuce, and green tea, because any increase in consumption of these items can cause an increase in dietary vitamin K and adversely affect INR levels. Many herbal supplements can also alter the effects of warfarin. The patient should consult with a pharmacist or physician before adding these items to his or her daily drug regimen.

The online version of the article has been corrected. HHN regrets the error.