Drug interactions between chondroitin/glucosamine/methylsulfonylmethane and Miradon

anisindione ↔ glucosamine

Applies to:Miradon (anisindione) and chondroitin/glucosamine/methylsulfonylmethane

MONITOR: A case report suggests that chondroitin and/or glucosamine may potentiate the hypoprothrombinemic effect of warfarin. The mechanism of interaction is unknown. Glucosamine is a chemical component of heparin, while chondroitin is a minor component of danaparoid and has been shown in vitro and in animals to prolong prothrombin time. However, adverse effects on coagulation and bleeding complications have not been reported in clinical studies using glucosamine and chondroitin dosages of up to 1.5 and 1.2 g/day, respectively. In the case report, a 69-year-old man who had been stabilized on warfarin 47.5 mg/week for four months demonstrated an increased INR (from 2.58 to 4.52) four weeks after initiating daily self-treatment with glucosamine hydrochloride (3 g) and chondroitin sulfate (2.4 g). The patient reported no other change in his medications or diet. After two weeks at a reduced warfarin dosage of 40 mg/week, the patient's INR returned to normal, and he remained stabilized at that dose for the next three months while he continued to take glucosamine and chondroitin.

MANAGEMENT: Patients should consult a healthcare provider before taking any herbal or alternative medicine. In patients treated with warfarin, the INR should be closely monitored following addition or discontinuation of chondroitin and glucosamine, and the warfarin dosage adjusted as necessary. The same precaution may be applicable during therapy with other oral anticoagulants, although clinical data are lacking. Patients should be advised to promptly report any signs of bleeding to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, unusual bleeding or bruising, red or brown urine, or red or black stools.

anisindione ↔ chondroitin

Applies to:Miradon (anisindione) and chondroitin/glucosamine/methylsulfonylmethane

MONITOR: A case report suggests that chondroitin and/or glucosamine may potentiate the hypoprothrombinemic effect of warfarin. The mechanism of interaction is unknown. Glucosamine is a chemical component of heparin, while chondroitin is a minor component of danaparoid and has been shown in vitro and in animals to prolong prothrombin time. However, adverse effects on coagulation and bleeding complications have not been reported in clinical studies using glucosamine and chondroitin dosages of up to 1.5 and 1.2 g/day, respectively. In the case report, a 69-year-old man who had been stabilized on warfarin 47.5 mg/week for four months demonstrated an increased INR (from 2.58 to 4.52) four weeks after initiating daily self-treatment with glucosamine hydrochloride (3 g) and chondroitin sulfate (2.4 g). The patient reported no other change in his medications or diet. After two weeks at a reduced warfarin dosage of 40 mg/week, the patient's INR returned to normal, and he remained stabilized at that dose for the next three months while he continued to take glucosamine and chondroitin.

MANAGEMENT: Patients should consult a healthcare provider before taking any herbal or alternative medicine. In patients treated with warfarin, the INR should be closely monitored following addition or discontinuation of chondroitin and glucosamine, and the warfarin dosage adjusted as necessary. The same precaution may be applicable during therapy with other oral anticoagulants, although clinical data are lacking. Patients should be advised to promptly report any signs of bleeding to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, unusual bleeding or bruising, red or brown urine, or red or black stools.