Infectious diseases caused by bacteria, and other harmful microorganisms, can cause the patient to suffer from pain and fever. Sometimes analgesics help in the symptomatic treatment to ease the pain, fever and inflammation caused by the harmful invading organism, but if the symptoms persist or they may get worse, then the physician uses the second line of defense, which are antibiotics.
Antibiotics are drugs that destroy a variety of bacteria. They are used mostly to treat infections, although in some people they may be prescribed to prevent infection, for example for patients with surgery are often given antibiotics to protect against bacteria that may be introduced during surgical procedures. Transplant patients or people with weak immune system also may need to take antibiotics.
Antibiotics are not effective in viral illnesses, such as colds or flu, but they may sometimes be prescribed in viral infection to prevent secondary bacterial infections. For example people with emphysema may be given antibiotics when they catch a cold because of their risk of developing a bacterial respiratory infection.
In determining which antibiotic to prescribe, a doctor may want to first identify the infecting bacteria by making a culture from the site of the infection or a broad spectrum antibiotic may be prescribed that is
The most common broad spectrum antibiotics are:
Penicillins, such as penicillin G, penicillin V, ampicillin, amoxicillin and cloxacillin;
Erythromycin and its relatives such as lincomycin and clindamycin;
Tetracycline and its relatives, such as oxytetracycline and demeclocycline.
Penicillins are often the antibiotic of first choice. They may be prescribed for infections caused by pneumonococci, meningococci, streptococci, gonococci and salmonella. They are commonly used to treat infections of the upper and lower respiratory tract and gastrointestinal and genitourinary tract infections as well as those of the ear, nose, throat and skin.
Erythromycin may be prescribed if an individual is allergic to penicillin or to treat special infections such as diphtheria, chlamydiosis, campylobacteriosis and certain kind’s pneumonia. Clindamycin is an antibiotic used for serious infections such as those of the bones or abdominal organs that fail.
Tetracyclines are most likely to be prescribed for the urinary tract infections, prostatic infections, pelvic inflammatory disease, acne, acute bronchitis, mild pneumonia and others.
Usually given as pills, antibiotics are taken orally for 10 to 14 days or in topical creams applied to skin. In more serious illness they may be injected in to the muscle or into the vein. By whatever route they are taken, they reach the blood stream and kill the bacteria by damaging their cell wall.
The most common side effects of antibiotics are:
Disturbance of the body’s normal flora: Antibiotics cannot differentiate between harmful and beneficial bacteria. Thus, when killing the disease causing bacteria, they also destroy the body’s normal flora that are usually present in the body and help in various functions. For example bacteria that help control yeast growth in the body may be destroyed leading to yeast infections.
Rashes and other allergic reactions: Penicillin is most likely to cause allergic reactions which may occur immediately within minutes or may be delayed foe weeks. If reaction occurs penicillin should never be used in future, because it may cause life threatening allergic reaction, and require emergency care. Other less common side effects include fever, painful joints, body swelling, wheezing, blood disorder, and kidney and liver damage.
Tetracycline may cause darkening of teeth in children whose mothers took it during pregnancy.
Once antibiotic therapy is begun, a full course of medication should be taken. Even though symptoms may disappear within few days, medication should be taken for at least for 10 days, stopping early can lead to bacterial resistance to further treatment with the same drug. Also they are not effective against viral infections such as cold and flu which have to be treated symptomatically.
Editor’s Note: Dr. Fasiha Hasham obtained her medical degree from Sindh Medical College and completed a residency at Jinnah Post Graduate Medical Centre in Pakistan before moving to the United States. Her specialties include Internal Medicine and Gynecology and Obstetrics. She is married with four children and lives in Farmington Hills, Michigan. The views expressed here are her own.