Common side effects associated with antibiotics include diarrhea, indigestion and bloating, loss of appetite and feeling sick, according to NHS Choices. Tetracyclines increase skin sensitivity to both natural and artificial light. Antibiotic use can disrupt the balance of bacteria in the body, leading to vaginal infections in women and causing upset stomach. Overuse of antibiotics can lead to bacterial resistance.
Symptoms of a mild allergic reaction to antibiotics include an itchy red rash, wheezing, coughing and tightness, states NHS Choices. Signs of a life-threatening allergic reaction requiring immediate medical intervention include rapid heartbeat, swelling of the neck, a sudden drop in blood pressure, and intense feelings of fear and confusion.
Antibiotics effectively treat bacterial infections, explains Merck Manual. They work by injuring or killing bacteria, adds WebMD. Antibiotics are completely ineffective against viral infections and fungal infections. To prevent bacterial resistance and reinfection, patients should complete their full course of prescribed antibiotics, even if they start feeling better.
As of 2015, there are more than 100 different antibiotics, according to eMedicineHealth. Examples of classes of antibiotics include penicillins, tetracyclines, cephalosporins, sulfonamides and fluoroquinolones. Oral antibiotics are available as capsules, tablets and liquids, and topical antibiotics to treat skin conditions are available as creams, lotions and ointments, states Patient.