Bone marrow depression chloramphenicol

It is important to monitor closely serum blood levels of chloramphenicol, particularly in patients with impaired liver or kidney function or when administering chloramphenicol with other drugs metabolized by the liver. Blood concentration levels exceeding 25 mcg/mL increase the risk of the patient developing bone marrow depression. 

The answer is c. (Hardman, pp 1134-1135.) Hematologic toxicity is by far the most important adverse effect of chloramphenicol The toxicity consists of two types (1) bone marrow depression (common) and (2) aplastic anemia (rare) Chloramphenicol can produce a potentially fatal toxic reaction, the gray baby syndrome, caused by diminished ability of neonates to conjugate chloramphenicol with resultant high serum concentrations. Tetracyclines produce staining of the teeth and phototoxicity... 

The most publicized adverse affects are those involving the hematopoietic system they are manifested by toxic bone marrow depression or idiosyncratic aplastic anemia. The bone marrow depression is dose related and is seen most frequently when daily doses exceed 4 g and plasma concentrations exceed 25 jig/mL. The bone marrow depression is characterized by anemia, sometimes with leukopenia or thrombocytopenia, but it is reversible on discontinuation of chloramphenicol. 

CHLORAMPHENICOL H2 RECEPTOR BLOCKERS -CIMETIDINE T adverse effects of chloramphenicol, e.g. bone marrow depression Additive toxicity Use with caution, monitor FBC regularly... 

Chloramphenicol causes two types of hematopoietic abnormality. The first is a dose-related toxic effect causing a bone marrow depression associated with inhibition of mitochondrial protein synthesis. Usually, discontinuing the antibiotic reverses this toxicity. 

Chaplin S. Bone marrow depression due to mianserin, phenylbutazone, oxyphenbutazone, and chloramphenicol—Part II. Adverse Drug React Acute Poisoning Rev 1986 5(3) 181-96. 

Risk for bone marrow depression ° Chloramphenicol given with ... 

Chloramphenicol is not recommended for use with a patient who is undergoing radiation therapy or who has bone marrow depression. 

Chloramphenicol can have an adverse interaction with alfentanil (Alfenta) by increasing alfentanil levels in the patient. Chloramphenicol is known to increase bone marrow depression when given with anticonvulsants. 

Thiamphenicol is a semi-synthetic derivative of chloramphenicol. It can cause reversible bone marrow depression, but fatal aplastic anemia has not been reported in humans. Oral bioavailability in pre-ruminant calves is 60%. It is somewhat less lipid- and somewhat more water-soluble than chloramphenicol and therefore crosses cell membranes less readily. Hepatic metabolism is limited, and elimination is primarily as parent drug in the urine. Limited published data indicate that it has a high distribution volume in ruminants. It has been used in feed in pigs and chickens, but such usage is now limited. 

In addition to the serious and potentially fatal bone marrow depression that can occur with chloramphenicol, it may also cause a milder, reversible bone marrow depression, which can oppose the treatment of anaemias with iron or vitamin B]2. 

Chloramphenicol can cause two forms of bone marrow depression. One is serious and irreversible, and can result in fatal aplastic anaemia, whereas the other is probably unrelated, milder and reversible, and appears to occur at chloramphenicol serum levels of 25 micrograms/mL or more. This occurs because chloramphenicol can inhibit protein synthesis, the first sign of which is a fall in the reticulocyte count, which reflects inadequate red cell maturation. This response to chloramphenicol has been seen in animals healthy individuals, a series of patients with liver disease," and in anaemic patients being treated with iron dextran or vitamin Bj2. 

As an example, the photodegradation products of chloramphenicol (nitroso-compounds and paranitro-benzaldehyde) are considered carcinogenic. These products will be formed in vitro and in vivo and can reach the bone marrow in rats [37]. Chronic use of chloramphenicol has been coimected with bone marrow depression, not caused by chloramphenicol itself. Apart from the question if this risk is estimated well [38], it can be avoided completely if the patient covers his skin if a dermal preparation has been applied and only use chloramphenicol as eye ointment 1 % at night. See also Sect. 10.5. 

Thiamphenicol is a synthetic chloramphenicol analogue with a molecular structure that appears to preserve tlie antibacterial properties, decrease markedly the metabolism by the liver, enhance kidney excretion, and eliminate tlie occurrence of aplastic anemia, although it is probably more liable to cause dose-dependent reversible depression of the bone marrow (15). These properties make it preferable in certain cases to chloramphenicol (36, 37). 

CHLORAMPHENICOL IRON 1 efficacy of iron Chloramphenicol depresses the bone marrow this opposes the action of iron Be aware monitor FBC and ferritin levels closely... 

Effects. Most animals treated with chloramphenicol experieiKie mild, reversible depression of bone marrow activity, manili ted as a reduced reticulocyte count, increased serum iron levels, and vacudation of eryihroid cells in the bone marrow. 

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