Editing Chloramphenicol (section)

===Formulations===

[[File:Sample of Chloramphenicol.jpg|thumb|Pure chloramphenicol]]
Chloramphenicol is available as a capsule or as a liquid. In some countries, it is sold as chloramphenicol [[palmitate]] [[ester]] (CPE). CPE is inactive, and is [[hydrolysis|hydrolysed]] to active chloramphenicol in the [[small intestine]]. No difference in [[bioavailability]] is noted between chloramphenicol and CPE.{{citation needed|date=March 2023}}

Manufacture of oral chloramphenicol in the U.S. stopped in 1991, because the vast majority of chloramphenicol-associated cases of aplastic anaemia are associated with the oral preparation. No oral formulation of chloramphenicol is available in the U.S. for human use.<ref>{{cite web |title=Chloramphenicol |url=https://go.drugbank.com/drugs/DB00446 |website=go.drugbank.com |access-date=23 June 2023 |date=June 23, 2023}}</ref>

====Intravenous====
The [[intravenous]] (IV) preparation of chloramphenicol is the succinate ester. This creates a problem: Chloramphenicol succinate ester is an inactive [[prodrug]] and must first be hydrolysed to chloramphenicol; however, the hydrolysis process is often incomplete, and 30% of the dose is lost and removed in the urine. Serum concentrations of IV chloramphenicol are only 70% of those achieved when chloramphenicol is given orally.<ref>{{cite journal | vauthors = Glazko AJ, Dill WA, Kinkel AW | title = Absorption and excretion of parenteral doses of chloramphenicol sodium succinate in comparison with per oral doses of chloramphenicol (abstract) | journal = Clinical Pharmacological Therapy | year = 1977 | volume = 21 | pages = 104 }}</ref> For this reason, the dose needs to be increased to 75&nbsp;mg/kg/day when administered IV to achieve levels equivalent to the oral dose.<ref>{{cite journal | vauthors = Bhutta ZA, Niazi SK, Suria A | title = Chloramphenicol clearance in typhoid fever: implications for therapy | journal = Indian Journal of Pediatrics | volume = 59 | issue = 2 | pages = 213–219 | date = March–April 1992 | pmid = 1398851 | doi = 10.1007/BF02759987 | s2cid = 13369284 }}</ref>

====Oily====
Oily chloramphenicol (or chloramphenicol oil suspension) is a long-acting preparation of chloramphenicol first introduced by Roussel in 1954; marketed as Tifomycine, it was originally used as a treatment for [[typhoid]]. Roussel stopped production of oily chloramphenicol in 1995; the [[International Dispensary Association Foundation]] has manufactured it since 1998, first in [[Malta]] and then in [[India]] from December 2004.<ref>{{cite journal | vauthors = Lewis RF, Dorlencourt F, Pinel J | title = Long-acting oily chloramphenicol for meningococcal meningitis | journal = Lancet | volume = 352 | issue = 9130 | pages = 823 | date = September 1998 | pmid = 9737323 | doi = 10.1016/S0140-6736(05)60723-4 | s2cid = 42224633 | doi-access = free }}</ref>

Oily chloramphenicol was first used to treat meningitis in 1975<ref>{{cite journal | vauthors = Rey M, Ouedraogo L, Saliou P, Perino L | title = Traitement minute de la méningite cérébrospinale épidémique par injection intramusculaire unique de chloramphénicol (suspension huileuse) | journal = Médecine et Maladies Infectieuses | language = fr | year = 1976 | volume = 6 | pages = 120–124 | doi = 10.1016/S0399-077X(76)80134-5 | issue = 4 }}</ref> and numerous studies since have demonstrated its efficacy.<ref>{{cite journal | vauthors = Wali SS, Macfarlane JT, Weir WR, Cleland PG, Ball PA, Hassan-King M, Whittle HC, Greenwood BM | title = Single injection treatment of meningococcal meningitis. 2. Long-acting chloramphenicol | journal = Transactions of the Royal Society of Tropical Medicine and Hygiene | volume = 73 | issue = 6 | pages = 698–702 | year = 1979 | pmid = 538813 | doi = 10.1016/0035-9203(79)90024-5 }}</ref><ref>{{cite journal | vauthors = Puddicombe JB, Wali SS, Greenwood BM | title = A field trial of a single intramuscular injection of long-acting chloramphenicol in the treatment of meningococcal meningitis | journal = Transactions of the Royal Society of Tropical Medicine and Hygiene | volume = 78 | issue = 3 | pages = 399–403 | year = 1984 | pmid = 6464136 | doi = 10.1016/0035-9203(84)90132-9 }}</ref><ref>{{cite journal | vauthors = Pécoul B, Varaine F, Keita M, Soga G, Djibo A, Soula G, Abdou A, Etienne J, Rey M | title = Long-acting chloramphenicol versus intravenous ampicillin for treatment of bacterial meningitis | journal = Lancet | volume = 338 | issue = 8771 | pages = 862–866 | date = October 1991 | pmid = 1681224 | doi = 10.1016/0140-6736(91)91511-R | hdl-access = free | s2cid = 31211632 | hdl = 10144/19393 }}</ref> It is the cheapest treatment available for meningitis (US$5 per treatment course, compared to US$30 for [[ampicillin]] and US$15 for five days of [[ceftriaxone]]). It has the great advantage of requiring only a single injection, whereas ceftriaxone is traditionally given daily for five days. This recommendation may yet change, now that a single dose of ceftriaxone (cost US$3) has been shown to be equivalent to one dose of oily chloramphenicol.<ref>{{cite journal | vauthors = Nathan N, Borel T, Djibo A, Evans D, Djibo S, Corty JF, Guillerm M, Alberti KP, Pinoges L, Guerin PJ, Legros D | title = Ceftriaxone as effective as long-acting chloramphenicol in short-course treatment of meningococcal meningitis during epidemics: a randomised non-inferiority study | journal = Lancet | volume = 366 | issue = 9482 | pages = 308–313 | year = 2005 | pmid = 16039333 | doi = 10.1016/S0140-6736(05)66792-X | url = https://fieldresearch.msf.org/bitstream/10144/23232/1/187_Ceftriaxone_as_effective_as_long-acting_-_Lancet_9482_2005.pdf | access-date = 2019-09-24 | url-status = live | hdl-access = free | s2cid = 20885088 | archive-date = 2021-08-28 | archive-url = https://web.archive.org/web/20210828032549/https://fieldresearch.msf.org/bitstream/handle/10144/23232/187_Ceftriaxone_as_effective_as_long-acting_-_Lancet_9482_2005.pdf;jsessionid=4FA77D2A307B91A4436B8801D471FF05?sequence=1 | hdl = 10144/23232 }}</ref>

====Eye drops====
Chloramphenicol is used in topical preparations ([[ointment]]s and [[eye drop]]s) for the treatment of bacterial conjunctivitis. Isolated case reports of [[aplastic anaemia]] following use of chloramphenicol eyedrops exist, but the risk is estimated to be of the order of less than one in 224,716 prescriptions.<ref name="Lancaster1998">{{cite journal | vauthors = Lancaster T, Swart AM, Jick H | title = Risk of serious haematological toxicity with use of chloramphenicol eye drops in a British general practice database | journal = BMJ | volume = 316 | issue = 7132 | pages = 667 | date = February 1998 | pmid = 9522792 | pmc = 28473 | doi = 10.1136/bmj.316.7132.667 }}</ref> In Mexico, this is the treatment used [[Preventive healthcare|prophylactically]] in newborns for [[neonatal conjunctivitis]].<ref>{{cite journal | vauthors = Kaštelan S, Anić Jurica S, Orešković S, Župić T, Herman M, Gverović Antunica A, Marković I, Bakija I | title = A Survey of Current Prophylactic Treatment for Ophthalmia Neonatorum in Croatia and a Review of International Preventive Practices | journal = Medical Science Monitor | volume = 24 | pages = 8042–8047 | date = November 2018 | pmid = 30413681 | pmc = 6240167 | doi = 10.12659/MSM.910705 | quote = According to current health policy in Mexico, preventive treatment for ophthalmia neonatorum in neonates is a medico-legal requirement and consists of the application of a single drop of ophthalmic chloramphenicol in both eyes shortly after birth }}</ref>