Chloramphenicol is a very powerful antibiotic that is effective against many different bacterial infections. It is typically used when less potent medications fail to resolve a patient's symptoms. Chloramphenicol may be given orally, through an intravenous line, or as a liquid eye drop solution depending on the type and severity of an infection. Some serious side effects and adverse reactions can occur when taking the medication, but health-care workers carefully monitor patients while they are on chloramphenicol to limit the risks of major health complications. Most people are able to start feeling better after about two weeks of daily treatment.
Drug researchers classify chloramphenicol as a bacteriostatic antimicrobial, which means that it is able to stop the growth of new bacteria in the body. When the drug reaches a bacterial cell, it penetrates the cell wall and binds to particular sections of the bacterium's RNA. It then inhibits the production and synthesis of new proteins that the cells need to grow, harness energy, and replicate. New bacteria cannot be formed, and the existing pathogens eventually expire.
Most doctors avoid using chloramphenicol as a first-course treatment option because of the risks involved with its use. Other antibiotics are usually tried first to see if they may be effective. If a patient does not respond after a few days, the prescribing doctor can review his or her medical history, allergy information, and current medication use to determine if chloramphenicol is safe enough to try. Hospitalized patients are typically given small intravenous doses every six hours, while people taking the drug orally are instructed to take three to four tablets or liquid doses per day. Exact dosing amounts and frequency of deliveries can vary from person to person, so it is important to check instructions with a doctor or pharmacist.
The most common side effects when taking chloramphenicol are diarrhea, nausea, vomiting, and stomach upset. A person may also develop a headache and experience minor, temporary mental confusion. Face swelling, skin hives, and breathing difficulties may be signs of an allergic reaction to the drug. Rarely, the medication can induce anemia or cause complications with bone marrow that can become serious. There also is a slight risk of developing leukemia or severe liver and heart damage as a consequence of taking the drug.
Doctors monitor use of chloramphenicol closely to avoid major complications. Blood work is regularly reviewed to make sure blood cell counts are normal and that the bacterial infection is indeed clearing up. Most patients respond well to the drug and do not experience health problems.