Term
Concentration-dependent killing |
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Definition
| A property of some antibiotics, especially aminoglycosides, whereby achieving a relatively high plasma drug concentration, even if briefly, results in the most effective bacterial kill (compare time-dependent killing). |
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Term
Extended-spectrum beta-lactamases (ESBLs) |
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Definition
| A group of beta-lactamase enzymes produced by some organisms that makes the organism resistant to all beta-lactam antibiotics (penicillins and cephalosporins) and aztreonam. Patients infected by such organisms must be in contact isolation, and proper hand washing is key to preventing the spread of the infections. |
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Term
Klebsiella pneumoniae carbapenemase (KPC) |
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Definition
| An enzyme first found in isolates of the bacterium klebsiella pneumoniae that renders the organism resistant to all carbapenem antibiotics as well as beta-lactam antibiotics and monobactams. Such organisms produce a very resistant infection. |
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Term
Methicillin-resistant Staphylococcus aureus (MRSA) |
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Definition
| A strain of Staphylococcus aureus that is resistant to the beta-lactamase penicillin known as methicillin. Originally, the abbreviation MRSA referred exclusively to methicillin-resistant S. aureus. It is now used more commonly to refer to strains of S. aureus that are resistant to several drug classes, and therefore, depending on the context or health facility, it may also stand for "multidrug-resistant S. aureus. |
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Term
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Definition
| One millionth of a gram. Be careful not to confuse with milligram (one thousandth of a gram), which is a thousand times greater than 1 microgram. Confusion of these two units sometimes results in drug dosage errors. |
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Term
Minimum inhibitory concentration (MIC) |
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Definition
| A laboratory measure of the lowest concentration of a drug needed to kill a certain standardized amount of bacteria. |
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Term
Multidrug-resistant organism |
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Definition
| Bacteria that are resistant to one or more classes of microbial drugs. These include multidrug-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing organisms, and Klebsiella pneumoniae carbapenemase-producing organisms. |
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Term
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Definition
| Toxicity to the kidneys, often drug induced and manifesting as compromised renal function. |
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Term
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Definition
| Toxicity to the ears, often drug induced manifesting as varying degrees of hearing loss that is more likely permanent than the impaired renal funtion resulting from nephrotoxicity. |
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Term
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Definition
| A period of continued bacterial suppression that occors after brief exposure to certain antibiotic drug classes, especially aminoglycosides and carbapenems. The mechanism of this effect is uncertain. |
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Term
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Definition
| A necrotizing inflammatory bowel condition that is often associated with antibiotic therapy. Some antibiotics (e.g. clindamycin) are more likely to produce it than others. A more general term that is also used is antibiotic-associated colitis. |
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Term
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Definition
| Drug interaction in which the bacterial killing effect of two antibiotics given together is greater than the sum of the individual effects of the same drug given alone. |
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Term
Therapeutic drug monitoring |
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Definition
| Ongoing monitoring of plasma drug concentrations and dosage adjustment based on these values as well as other laboratory indicators such as kidney and liver function test results; it is often carried out by a pharmacist in collaboration with medical, nursing, and laboratory staff. |
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Term
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Definition
| A property of most antibiotic classes whereby prolonged high plasma drug concentrations are required for effective bacterial kill (compare concentration-dependent killing). |
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Term
Vancomycin-resistant Enterococcus (VRE) |
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Definition
| Enterococcus species that are resistant to beta-lactam antibiotics and vancomycin. Most commonly refers to Enterococcus faecium. |
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