Are tetracyclines time or concentration dependent?

Pharmacodynamics: Tetracyclines produce a combination of concentration and time-dependent killing (AUC:MIC ratio).

Which antibiotics are time or concentration dependent?


Time-Dependent (with minimal or no PAE) Concentration-Dependent (with PAE)
Beta-lactams Vancomycin Aminoglycosides Daptomycin Fluoroquinolones Metronidazole Azithromycin Ketolides

What is concentration dependent antibiotics?

Concentration-Dependent Killing: Other classes of antibiotics, such as aminoglycosides and quinolones, have high concentrations at the binding site which eradicates the microorganism and, hence, these drugs are considered to have a different kind of bacterial killing, named concentration-dependent killing.

Which drugs are concentration dependent?

Fluoroquinolones, aminoglycosides and metronidazole are concentration-dependent and beta-lactams, macrolides, lincosamides and glycopeptides are time-dependent.

Are tetracyclines broad or narrow spectrum?

Tetracyclines are broad-spectrum agents, exhibiting activity against a wide range of gram-positive and gram-negative bacteria, atypical organisms such as chlamydiae, mycoplasmas, and rickettsiae, and protozoan parasites.

Are cephalosporins time or concentration dependent?

In contrast, others have reported that cephalosporins exhibited largely time-dependent bactericidal effects which were independent of concentration except for early bactericidal action.

Are tetracyclines bacteriostatic or bactericidal?

Tetracycline, considered to be a bacteriostatic an- tibiotic, has slow bactericidal activity against Staphylococcus aureus in vitro [1]. The concen- tration of tetracycline required to inhibit the growth of stable, cell wall-defective S.

Is azithromycin concentration dependent?

Azithromycin belongs to the parent class of macrolides that are characteristically bacteriostatic. Some evidence suggests that this molecule demonstrates bactericidal kill and has concentration-dependent effects.

Are cephalosporins narrow or broad spectrum?

Cephalosporins are broad spectrum antibiotics similar to penicillins. They have a beta-lactam ring which interferes with bacterial cell wall synthesis by binding to penicillin-binding proteins, eventually leading to cell lysis and death.

What is concentration dependent?

Concentration dependent (time independent) means that the rate and extent of microorganism killing are a function of the antimicrobial concentration (increase as the concentration increases).

Are macrolide bactericidal or bacteriostatic?

Mechanism of Action [7] Macrolides are considered to be bacteriostatic as they only inhibit protein synthesis, although, at high doses, they can be bactericidal.

Is doxycycline time or concentration-dependent?

Doxycycline efficacy is time-dependent rather than concentration-dependent, meaning that bactericidal activity is predicated on the amount of time bacteria are exposed to a concentration above the minimum inhibitory concentration (MIC). We therefore aimed to determine the AUC0-24:MIC.

What is the half life of tetracycline 500mg?

Pharmacodynamics: Tetracyclines produce a combination of concentration and time-dependentkilling (AUC:MIC ratio). Pharmacokinetics: Dose of 500mg PO: Cmax: 1.5-5 mcg/mL; Tmax: 2-4 hours; Half-life: 6-12 hours; Volume of distribution: 108 L/kg; Table 3 Adverse Effects:

How are tetracyclines different from other antimicrobials?

The tetracyclines are broad-spectrum antibiotics with similar antimicrobial features, but they differ somewhat from one another in terms of their spectra and pharmacokinetic disposition.

How are tetracyclines eliminated after a parenteral dose?

Tetracyclines are also eliminated in milk; concentrations peak 6 hr after a parenteral dose, and traces are still present up to 48 hr later. Concentrations in milk usually attain ~50%–60% of the plasma concentration and are often higher in mastitic milk. Tetracyclines also are excreted in saliva and tears.

Which is the least bioavailable tetracycline for humans?

Oral bioavailability, however, can vary markedly among drugs, with chlortetracycline being the least and doxycycline the most orally bioavailable. Tetracyclines at therapeutic concentrations should not be administered PO to ruminants: they are poorly absorbed and can substantially depress ruminal microfloral activity.