Xenical / Alli

Generically known as Orlistat, Xenical works by blocking fat from being absorbed in the body. This drug is prescribed to treat obesity. Xenical is produced by Roche Holdings, while Alli was developed by GlaxoSmithKline. Xenical was approved by the FDA in 1999, and Alli, the over-the-counter form of the drug, was approved in 2007.

In 2009, the FDA announced that it was investigating Xenical after it received reports of adverse liver events in patients. From 1999 to 2008, the FDA received 32 reports of serious liver injury associated with the weight-loss drug. Of these cases, 27 patients were hospitalized while six patients suffered from liver failure. Many of these cases were reported outside of the United States and were seen through symptoms such as jaundice, weakness and abdominal pain.

Xenical has also been linked to aberrant crypt foci (ACF)—which can be an early indication of colon cancer.

Serious side effects may include:

• Severe pain in your lower back, blood in your urine
• Urinating less than usual or not at all
• Drowsiness, confusion, mood changes, increased thirst
• Swelling, weight gain, feeling short of breath
• Severe pain in your upper stomach spreading to your back, nausea and vomiting, fast heart rate
• Nausea, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)

Common and mostly temporary side effects may include:

• Oily spotting in your undergarments
• Oily or fatty stools
• Orange or brown colored oil in your stool
• Gas with discharge, an oily discharge
• Loose stools, or an urgent need to go to the bathroom, inability to control bowel movements
• An increased number of bowel movements
• Stomach pain, nausea, vomiting, diarrhea, rectal pain
• Weakness, dark urine, clay-colored stools, itching, loss of appetite, or jaundice (yellowing of the skin or eyes)

Other side effects that may occur:

• Problems with your teeth or gums
• Cold symptoms such as stuffy nose, sneezing, cough
• Fever, chills, sore throat, flu symptoms
• Headache, back pain
• Mild skin rash