Opsomycetin

125 mg/5 ml

Manufactured by:

60 ml bottle: ৳ 44.71

Indication

Bacterial infections

Chloramphenicol is an antibiotic that is clinically useful for, and should be reserved for, serious infections caused by organisms susceptible to its antimicrobial effects when less potentially hazardous therapeutic agents are ineffective or contraindicated. However, chloramphenicol may be chosen to initiate antibiotic therapy on the clinical impression that one of the conditions below is believed to be present. In vitro sensitivity tests should be performed concurrently so that the drug may be discontinued as soon as possible if less potentially dangerous agents are indicated by such tests. The decision to continue use of chloramphenicol, rather than another antibiotic when both are suggested by in vitro studies to be effective against a specific pathogen, should be based upon severity of the infection, susceptibility of the pathogen to the various antimicrobial drugs, and the efficacy of the various drugs in the infection

Pharmacology

In vitro, chloramphenicol exerts mainly a bacteriostatic effect on a wide range of Gram-negative and Gram positive bacteria and is active against rickettsiae, the lymphogranuloma-psittacosis group and Vibrio cholerae. It is particularly active against Salmonella typhi and Haemophilus influenzae. The mode of actions is through interference or inhibition of protein synthesis in intact cells and cell-free systems. Antagonism has been demonstrated in vitro between chloramphenicol, erythromycin, clindamycin and lincomycin. Chloramphenicol is rapidly absorbed from the GI tract. Chloramphenicol palmitate is hydrolyzed in the GI tract and is absorbed as free chloramphenicol.

Following oral administration of a single one gram dose of chloramphenicol base to healthy adults, average peak plasma chloramphenicol concentrations of about 11 mcg/ml were attained with 1-3 hours. Cumulative dosing gave a peak of 18 mcg/ml after the fifth dose of one gram, every 6 hours. Mean serum levels were 8-14 mcg/ml over a 48 hour period.

Most of the drug is excreted in the urine. Despite the small proportion of unchanged drug excreted in the urine, the concentration of free chloramphenicol in the urine is relatively high. From 8% to 12% of the antibiotic is excreted as free chloramphenicol. The remainder is excreted as inert metabolites, mainly glucuronate. Small amounts of active drug are found in bile and feces. Chloramphenicol diffuses rapidly, but its distribution is not uniform. Highest concentrations are found in liver and kidney, and lowest concentrations are found in brain and cerebrospinal fluid (CSF). Chloramphenicol enters CSF even in the absence of meningeal inflammation, appearing in concentrations about half of those found in the blood.

Dosage & Administration

Interaction

Chloramphenicol has been shown to retard the biotransformation of tolbutamide, phenytoin, and dicoumarol in man. Chloramphenicol should be used with caution if administered concomitantly with lincomycin, clindamycin, or erythromycin. In vitro experiments have demonstrated that binding sites for erythromycin, lincomycin, clindamycin and chloramphenicol overlap and competitive inhibition may occur. Rifampin therapy can reduce Chloramphenicol concentrations.

Side Effects

Pregnancy & Lactation

Precautions & Warnings

It is essential that adequate hematologic functions be closely monitored during treatment with the drug. While hematologic determinations may detect early peripheral hematologic changes, such as leukopenia, reticulocytopenia, or granulocytopenia, before they become irreversible, such determinations cannot be relied on to detect bone marrow depression prior to development of aplastic anemia

Use in Special Populations

Therapeutic Class

Macrolides

Overdose Effects

Levels exceeding 25 mcg/ml are frequently considered toxic. Chloramphenicol toxicity can be evidenced by serious hemopoietic effects such as aplastic anemia, thrombocytopenia, leukopenia, as well as increasing serum iron levels, nausea, vomiting and diarrhea. In the case of serious overdosage, charcoal hemoperfusion may be effective in removing chloramphenicol from plasma. Exchange transfusion is of questionable value following massive overdosage, especially in neonates and infants.

Storage Conditions

Store in a cool dry place. Keep bottle securely closed. Protect from light.