Alli is a low-dose over-the-counter version of the prescription medication Xenical. Both contain the drug orlistat, which prevents the absorption of some of the fat you eat. Orlistat is associated with certain types of bleeding risks. Although you can buy Alli without a prescription, talk with your doctor before taking this medicine.
Side Effects
You may be able to prevent common side effects of Alli by eating a diet with no more than 30 percent of calories from fat, and by spreading your fat intake over all your meals. Higher fat intake is connected with side effects such as gas, stomach pain, oily spotting, sudden bowel movements, and soft and fatty stools. Alli also can cause severe diarrhea, and some consumers have reported rectal bleeding as a side effect, according to NetDoctor. If you experience severe or chronic rectal bleeding while taking Alli, consult your doctor.
Anticoagulants and Vitamin K
Alli interacts with anticoagulant medications such as warfarin, which doctors prescribe to prevent the development of blood clots or to stop a blood clot from becoming larger. People taking anticoagulants need routine blood tests to check their blood clotting time so the doctor can determine if a change in dosage is needed. They also need to keep their intake of vitamin K consistent, because vitamin K is essential for blood clotting. Lowering vitamin K intake increases the effect of anticoagulants, thus increasing the risk of bleeding. A diet using Alli can affect vitamin K levels in the body for two reasons.
Alli and Anticoagulants
Vitamin K requires fat for absorption. Taking orlistat on a regular basis may decrease the absorption of vitamin K and other fat soluble vitamins, and increase the effects of anticoagulant medication, according to an article published in the April 2003 issue of the "Annals of Pharmacotherapy." In addition, while taking Alli, you may change your diet in ways that decrease the amount of vitamin K you consume. If you take warfarin or another blood-thinning medication along with Alli, watch for signs of lowered clotting ability such as prolonged bleeding from cuts, nosebleeds, bleeding from your gums while brushing your teeth, or increased menstrual flow. You could need a change in medication dosage.
Case Study
The "Annals of Pharmacotherapy" article details a case study in which a patient taking warfarin developed an elevated international normalized ratio, or INR, which doctors use to measure how long it takes blood to clot. The patient had recently begun taking orlistat for weight reduction, and had made no other changes to his medication regimen. A change in warfarin dosage resolved the problem.
Member Comments