Symptoms of Chloramphenicol: What to Watch For

Chloramphenicol is a powerful antibiotic. Most people never have a problem, but this drug can cause a range of reactions — from mild stomach upset to rare, life-threatening conditions. Knowing which symptoms are routine and which need urgent care can make a big difference.

Common and mild symptoms

Some reactions are fairly common and often go away on their own. These include nausea, vomiting, diarrhea, and mild skin rash. You might also notice headache, dizziness, or changes in taste. If these are mild, your doctor may suggest managing them without stopping the antibiotic, but always check before deciding.

Some people get a skin rash or itch. That can be just an allergic reaction that is easy to treat, but if the rash spreads quickly, looks blistered, or is accompanied by fever, call your provider right away.

Serious signs — act fast

There are a few side effects linked to chloramphenicol that need immediate attention. The most serious is bone marrow suppression, which can show up as aplastic anemia. Watch for extreme tiredness, pale skin, shortness of breath, unexplained bruises, nosebleeds, bleeding gums, or frequent infections like sore throats and fevers. These symptoms can appear while you’re taking the drug or even weeks later. If you see them, stop the medication and get medical help right away.

Newborns are at special risk of "gray baby syndrome." Signs include poor feeding, vomiting, floppy muscles, low body temperature, breathing trouble, and a bluish or gray skin tone. This is an emergency — newborns who show these signs need immediate hospital care.

Neurological problems are rarer but possible. If you develop sudden vision changes, numbness, tingling in your hands or feet, or unusual weakness, tell your doctor. Some people also develop severe allergic reactions with swelling of the face or throat and trouble breathing — go to the emergency room if that happens.

Finally, chloramphenicol can affect the liver. Look for yellowing of the skin or eyes, dark urine, or persistent stomach pain. Blood tests that track liver enzymes and blood cell counts help catch problems early.

What should you do? Ask your doctor to check a baseline complete blood count (CBC) before starting and to repeat tests regularly during treatment. If you notice any worrying signs — especially heavy bruising, bleeding, severe sore throat, high fever, sudden tiredness, or changes in a newborn — stop the drug and seek medical care immediately. Keep a list of all medicines you take and tell your provider about other health issues before starting chloramphenicol.

Quick action can prevent complications. If something feels off while taking chloramphenicol, trust your gut and call your healthcare provider. Better safe than sorry.