• Augmentin XR Sr is a brand name for a prescription antibiotic medication. The drug contains a combination of amoxicillin and clavulanate potassium that is formulated so that the medication is released gradually into your bloodstream over a 12-hour time frame, explains RxList.com. Doctors commonly prescribe Augmentin XR Sr for the treatment of illnesses caused by bacteria. Despite its effectiveness in eliminating bacterial infections, Augmetin XR Sr poses a risk for side effects in some patients.
  
  

Gastrointestinal

• Occurring in approximately 14.5 percent of patients, diarrhea is the most common side effect of Augmentin XR Sr, according to FDA clinical trials published by RxList.com. Nausea and loose stools are also common and affect approximately 1.6 to 2.1 percent of users. Less common, but not dangerous, side effects of Augmentin XR Sr include vomiting, indigestion and a black, hairy appearance of the tongue. Infrequently, use of Augmentin XR Sr results in inflammation of the digestive system. This poses a risk for a condition known as pseudomembranous colitis, a life-threatening inflammation of the colon that causes severe and, often, bloody diarrhea.
  
  

Hypersensitivity

• Augmentin XR Sr has the potential to cause severe allergic reactions in some patients, warns RxList.com. One such reaction is angioedema, which is severe swelling of the face, throat or extremities. Another is anaphylaxis, which causes rapid heartbeat, wheezing and hives. In rare cases, the sensitivity results in Stevens-Johnson syndrome, a skin disorder that causes the formation of fluid-filled sacs or blisters on the skin. Severe cases of anaphylaxis or Stevens-Johnson syndrome are fatal without medical treatment.
  
  

Neurological

• Although uncommon, neurological side effects may occur with Augmentin XR Sr use, including agitation, anxiety, confusion, dizziness, headache and insomnia. Despite their unpleasantness, these effects rarely pose any risk for long-term health complications and diminish when you stop using the drug, explains RxList.com. Rarely, use of Augmentin XR Sr causes convulsions or seizures.
  
  

Hepatic

• Ampicillin antibiotics, like amoxicillin, have the potential to cause liver dysfunction, putting people who take Augmentin XR Sr at risk for developing liver-related side effects, explains RxList.com. Such symptoms include yellowing of your skin or eyes and clay-colored stools. In most cases, liver dysfunction caused by Augmentin is reversible and causes no permanent damage. Approximately one out of every four million people who takes the drug dies from liver dysfunction.
  
  

Renal and Reproductive

• Approximately 3 percent of women who take Augmentin XR Sr develop vaginal yeast infections, reports RxList.com. Because the drug is known to cause fetal abnormalities in laboratory animals, doctors rarely prescribe Augmentin for use in pregnant women. A much more rare complication from the antibiotic is interstitial nephritis, which is swelling of the interior structures of the kidneys. Symptoms of the condition include bloody urine, fever and swelling of your extremities, reports the U.S. National Library of Medicine.
  
  

Hematological

• Augmentin XR Sr has the potential to alter the levels of certain cells in the bloodstream, like red or white blood cells, explains RxList.com. Another hematological complication of Augmentin is thrombocytopenia, a shortage of blood platelets, which are necessary for blood clotting. Because of the risk of thrombocytopenia, doctors rarely prescribe Augmentin XR Sr for patients who are taking blood-thinning drugs, like Warfarin.