Doxycycline is medication for bacterial infections including acne, Lyme disease and anthrax, as well as pneumonia and certain respiratory infections. According to Medline Plus, this medication halts bacterial growth and spread. Doxycycline has various side effects ranging from mild and severe that both patients should consider before taking this medication.
Gastrointestinal Side Effects
Gastrointestinal side effects have been associated with the administration of doxycycline, according to RxList.com. Side effects in the digestive system include anorexia, vomiting, nausea, diarrhea, difficulty swallowing, liver damage and swelling in the esophagus.
Side Effects on the Skin
Doxycycline can cause numerous side effects to the skin, according to Drugs.com. The most common side effect on the skin is a rash. The rash usually appears red and composed of alternating flat and raised lesions. Patients may experience a similar rash on areas that exposed to light or photosensitivity. Uncommonly, patients may experience a severe rash that destroys their hair.
Bilirubin Abnormalities
Bilirubin is a yellow pigment synthesized in the liver and in the red blood cells. If bilirubin is not excreted properly then they body can show symptoms. Doxycycline interferes with the proper metabolism of bilirubin, according to MedlinePlus. Symptoms of this bilirubin abnormality include jaundice or a yellowing of the skin and eyes, pale colored stool and dark urine. The jaundice results from a buildup of the yellow bilirubin in the skin. Bilirubin is the pigment that gives the stool its normal color, but when bilirubin cannot enter the intestine, the stool becomes pale. The patient's urine darkens because the excess bilirubin is excreted in the urine and the pigment darkens the urine.
Blood
Doxycycline may have various side effects on blood cell production and metabolism, according to RxList.com. Patients may experience anemia or low levels of red blood cells. Patients may also develop low levels of various white blood cells and this may affect the patient's immune response. Platelet levels also drop and this may cause excess bleeding.
Kidney Function
The kidneys can become damaged by doxycycline, according to Drugs.com. Blood urea nitrogen (BUN) is a blood test done to measure kidney function. The BUN level rises in patients who have received large doses of doxycycline. This indicates decreasing kidney function. Patients who experience a large increase in BUN levels might need to undergo further testing for kidney function. Physicians should take patients off doxycycline and give them another antibiotic that does not prove as toxic to the kidneys.
