Chloramphenicol: what it is and why doctors still use it

Chloramphenicol is an older broad‑spectrum antibiotic that you might see as eye drops, ointment, or in oral/injectable form. It can work when other antibiotics fail, but it comes with uncommon — yet serious — risks. If your doctor mentions chloramphenicol, this page helps you understand what it treats, the safety concerns, and simple things to watch for.

What it treats and how it works

Chloramphenicol blocks bacteria from making essential proteins, which stops them from growing. Because of that broad action, it’s useful for certain severe infections or for eye infections like bacterial conjunctivitis when topical treatment is needed. In many countries, topical eye preparations are common. Systemic (oral or IV) use is now mostly reserved for severe, resistant infections or where safer alternatives aren’t available.

Doctors pick chloramphenicol when other antibiotics don’t work or when a specific bug is known to be sensitive to it. For routine infections, there are usually safer choices. That’s why you’ll often see chloramphenicol offered as a backup, not first-line therapy.

Side effects, major risks, and practical safety tips

Most people using topical eye drops have few problems beyond mild irritation. But systemic use can cause serious issues. Two big ones to know:

- Aplastic anemia: a rare but life‑threatening condition where the bone marrow stops making blood cells. It can happen weeks or months after exposure and may be irreversible. Because of that risk, long courses of chloramphenicol are avoided when possible.

- Gray baby syndrome: newborns, especially premature infants, can’t clear chloramphenicol well. This can cause low body temperature, low heart rate, vomiting and a grayish skin color. Chloramphenicol is generally avoided in newborns.

Other side effects include stomach upset, rash, and reversible drops in white blood cell counts. If you’re on systemic chloramphenicol for more than a few days, doctors often check blood counts during treatment.

Practical tips: only use chloramphenicol when prescribed. If you get eye drops, follow the dosing and avoid touching the bottle tip to your eye. Tell your provider if you're pregnant, breastfeeding, or caring for a newborn. If you develop unusual tiredness, easy bruising, high fever, or persistent sore throat while taking it, contact your doctor — those can be signs of low blood counts.

Resistance is a concern for many antibiotics, including chloramphenicol. That’s another reason clinicians try to use targeted therapy based on culture results when possible, rather than broad use. If you have questions about why your doctor chose chloramphenicol, ask what alternatives were considered and whether monitoring will be done.

Need more detail about a specific form — eye drops versus pills — or what monitoring looks like? Reach out to your healthcare provider or pharmacist. They can explain how this drug fits your situation and what to expect while using it.