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Chloramphenicol Side Effects

For the Consumer

Applies to chloramphenicol: powder for solution

Along with its needed effects, chloramphenicol may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Stop taking chloramphenicol and get emergency help immediately if any of the following effects occur:


- in babies only
  • Bloated stomach
  • drowsiness
  • gray skin color
  • low body temperature
  • uneven breathing
  • unresponsiveness

Check with your doctor immediately if any of the following side effects occur while taking chloramphenicol:

Less Common

  • Pale skin
  • sore throat and fever
  • unusual bleeding or bruising
  • unusual tiredness or weakness (the above side effects may also occur up to weeks or months after you Stop taking chloramphenicol)


  • Confusion, delirium, or headache
  • eye pain, blurred vision, or loss of vision
  • numbness, tingling, burning pain, or weakness in the hands or feet
  • skin rash, fever, or difficulty in breathing

Some side effects of chloramphenicol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less Common

For Healthcare Professionals

Applies to chloramphenicol: compounding powder, injectable powder for injection, oral capsule


Hematologic side effects due to chloramphenicol-induced bone marrow depression are the most significant adverse reactions and have included aplastic anemia, hypoplastic anemia, thrombocytopenia, pancytopenia, and granulocytopenia. Idiosyncratic aplastic anemia occurs in approximately 1 in 20,000 to 1 in 40,000 cases, is fatal in 70% of affected patients, and resolves in only 10% of patients. Reversible bone marrow suppression is more common, and is dose-related. Paroxysmal nocturnal hemoglobinuria has also been reported. Hemolysis may occur in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency.[Ref]

Aplastic anemia is idiosyncratic and dose-independent. It has been reported in patients who have received intravenous, oral, and topical (including ophthalmologic ointment) chloramphenicol 3 to 12 weeks after initiation of therapy.

Reversible bone marrow suppression may present as early as 5 days after therapy is begun as pancytopenia, is more common with plasma chloramphenicol levels of 25 mcg/mL or more, and may result in high serum iron levels due to lack of bone marrow clearance of iron.[Ref]


Hypersensitivity side effects have included fever, macular and vesicular rashes, angioedema, urticaria, anaphylaxis, fever, hypersensitivity myocarditis, and angioedema. Herxheimer's reactions have been reported during treatment of typhoid fever. Extremely rare cases of contact dermatitis have been reported.[Ref]

Anaphylaxis may present with urticarial rash, bronchospasm, and angioedema, and is rare.[Ref]

Nervous system

Nervous system side effects have included headache, mental confusion, delirium, ototoxicity, sensorineural hearing loss, optic neuritis, peripheral neuritis, and encephalopathy.[Ref]

Sensorineural hearing loss has been reported after oral administration and after topical administration of chloramphenicol to the outer ear. The proposed mechanism is inhibition of mitochondrial protein synthesis in highly oxidative organs.[Ref]


Psychiatric side effects have included mild depression.


Gastrointestinal side effects have infrequently included nausea, vomiting, glossitis, stomatitis, and enterocolitis.[Ref]


Cardiovascular side effects have rarely included cardiomyopathy. The proposed mechanism is inhibition of mitochondrial protein synthesis in highly oxidative organs.[Ref]


Hepatic side effects have included rare cases of hepatitis.[Ref]


Gray syndrome has been reported in neonates, premature infants, and infants. It usually appears after 3 to 4 days of chloramphenicol therapy and manifests as abdominal distension with or without vomiting, progressive pallid cyanosis, irregular respiration, vasomotor collapse, and death within a few hours after onset. In one case gray syndrome was reported in a neonate whose mother had received chloramphenicol during labor. High chloramphenicol serum levels (greater than 90 mcg/mL) have been associated with gray syndrome and large doses have been associated with a rapidly fatal course. Symptoms are frequently reversible with complete recovery if chloramphenicol is discontinued immediately.[Ref]


1. Doona M, Walsh JB "Use of chloramphenicol as topical eye medication: time to cry halt? bone marrow aplasia also occurs with ocular use." BMJ 310 (1995): 1217-8

2. "Product Information. Chloromycetin (chloramphenicol)." Parke-Davis, Morris Plains, NJ.

3. Del Giacco GS, Petrini MT, Jannelli S, Carcassi U "Fatal bone marrow hypoplasia in a shepherd using chloramphenicol spray." Lancet 1 (1981): 945

4. Fraunfelder FT, Bagby GC, Kelly DJ "Fatal aplastic anemia following topical administration of ophthalmic chloramphenicol." Am J Ophthalmol 93 (1982): 356-60

5. Smith AL, Weber A "Pharmacology of chloramphenicol." Pediatr Clin North Am 30 (1983): 209-36

6. Calderwood SB, Moellering RC "Common adverse effects of antibacterial agents on major organ systems." Surg Clin North Am 60 (1980): 65-81

7. Diskin C "Paroxysmal nocturnal hemoglobinuria after chloramphenicol therapy." Mayo Clin Proc 80 (2005): 1392, 1394

8. Finegold SM "Therapy for infections due to anaerobic bacteria: an overview." J Infect Dis 135 Suppl (1977): S25-9

9. Abrams SM, Degnan TJ, Vinciguerra V "Marrow aplasia following topical application of chloramphenicol eye ointment." Arch Intern Med 140 (1980): 576-7

10. Shalit I, Marks MI "Chloramphenicol in the 1980s." Drugs 28 (1984): 281-91

11. Farber BF, Brody JP "Rapid development of aplastic anemia after intravenous chloramphenicol and cimetidine therapy." South Med J 74 (1981): 1257-8

12. West BC, DeVault GA Jr, Clement JC, Williams DM "Aplastic anemia associated with parenteral chloramphenicol: review of 10 cases, including the second case of possible increased risk with cimetidine." Rev Infect Dis 10 (1988): 1048-51

13. Alavi JB "Aplastic anemia associated with intravenous chloramphenicol." Am J Hematol 15 (1983): 375-9

14. Schewach-Millet M, Shpiro D "Urticaria and angioedema due to topically applied chloramphenicol ointment." Arch Dermatol 121 (1985): 587

15. Liphshitz I, Loewenstein A "Anaphylactic reaction following application of chloramphenicol eye ointment." Br J Ophthalmol 75 (1991): 64

16. Van Joost T, Dikland W, Stolz E, Prens E "Sensitization to chloramphenicol: a persistent problem." Contact Dermatitis 14 (1986): 176-8

17. Perkins JB, Raasch RH "Hypersensitivity reaction following chloramphenicol administration in a patient with typhoid fever." Drug Intell Clin Pharm 21 (1987): 343-5

18. Kounis GN, Kouni SA, Chiladakis JA, Kounis NG "Comment: Mesalamine-Associated Hypersensitivity Myocarditis in Ulcerative Colitis and the Kounis Syndrome (February)." Ann Pharmacother 43 (2009): 393-4

19. Palchick BA, Funk EA, McEntire JE, Hamory BH "Anaphylaxis due to chloramphenicol." Am J Med Sci 288 (1984): 43-5

20. Iqbal SM, Srivatsav CBP "Chloramphenicol ototoxicity." J Laryngol Otol 98 (1984): 523-5

21. Biancaniello T, Meyer R, Kaplan S "Chloramphenicol and cardiotoxicity." J Pediatr 98 (1981): 828-30

22. Phelps SJ, Tsiu W, Barrett FF, et al "Chloramphenicol-induced cardiovascular collapse in an anephric patient." Pediatr Infect Dis J 6 (1987): 285-8

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.