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Several new safety labeling changes have been required by the Food and Drug Administration (FDA) for the widely used anticoagulant drug warfarin (COUMADIN). These changes to the drug’s professional product labeling, or “package insert,” were made in May 2002.
A warning about breastfeeding has been changed to reflect new information. Some breast-fed infants whose mothers were treated with warfarin had abnormal prolongations in their blood clotting tests (although not as prolonged as those of...
Several new safety labeling changes have been required by the Food and Drug Administration (FDA) for the widely used anticoagulant drug warfarin (COUMADIN). These changes to the drug’s professional product labeling, or “package insert,” were made in May 2002.
A warning about breastfeeding has been changed to reflect new information. Some breast-fed infants whose mothers were treated with warfarin had abnormal prolongations in their blood clotting tests (although not as prolonged as those of the mothers), indicating that they had received warfarin.
Warfarin interacts with a long list of drugs and most of these changes involve the addition of new drug interactions. The following products have been added to the list of drugs that can increase the effect of warfarin and thus, potentially, raise a risk of bleeding:
The cholesterol-lowering drugs atorvastatin (LIPITOR) and pravastatin (PRAVACHOL). There have also been some reports of these drugs decreasing the effectiveness of warfarin.
Also added to the list of drugs that can increase the effect of warfarin is the antifungal drug miconazole (MONISTAT) for vaginal use. There are a number nonprescription miconazole vaginal products that may interact with warfarin. These include: FEMIZOL-M VAGINAL CREAM, MONISTAT VAGINAL CREAM, MONISTAT-7 VAGINAL SUPPOSITORIES, MONISTAT DUAL-PAK, MONISTAT 3, M-ZOLE 3 COMBINATION PACK, and M-ZOLE 7 DUAL PACK.
There have also been changes in the list of herbal dietary supplements that can dangerously increase the effect of warfarin. Ginseng has been added to the list, which now includes the following supplements: bromelains, danshen, dong quai (Angelica sinensis), garlic, St. John’s Wort, ginkgo biloba, and ginseng.
Bromelains come from the enzymes found in pineapples and are promoted on some Internet sites for chronic pain. Danshen, or red sage root, is a traditional Chinese herb claimed to be useful for a wide variety of conditions including postmenstrual pain, postpartum bleeding and pain, angina pectoris (chest pain), furuncles, carbuncles, and joint pain, as well as painful swellings in the liver and spleen. Numerous claims are made for dong quai including to help nourish female glands, regulate monthly cycles, rebuild blood, and help a mother’s condition after the birth of a baby.
Garlic is a popular supplement sold as an antioxidant that can lower high blood pressure. St. John’s Wort is hyped as a natural antidepressant. Ginkgo biloba is claimed to improve memory and Alzheimer’s disease. Among other claims for ginseng are that it increases resistance to the effects of stress and improves circulation and mental functioning.
None of the herbal supplements listed above have been shown to be safe and effective for any use. In addition, because there is no regulatory oversight of dietary supplements, consumers cannot be assured that what is on the label is actually in the bottle.
What You Can Do
The list of products that may interact with warfarin will continue to grow in the future. You should not change your use of any other prescription drugs, over-the-counter products, and herbal supplements except on advice of your doctor.
