Learning Objects : Lifelong Application

RLO: Pharmacokinetic and Pharmacodynamic Influences of Aminoglycoside Dosing

Resources

Title/link	Description
British National Formulary	Section 5.1.4 provides information on the clinical use of aminoglycosides. (This resource requires free registration, or use of an Athens account.)
Hartford Nomogram	Original article validating the Hartford Nomogram: Nicolau, D.P., et al., 1995. Experience with a once-daily aminoglycoside program administered to 2,184 adult patients. Antimicrobial agents and chemotherapy [online], 39(3), 650-655. (This resource requires Adobe Reader.)
Pharmacokinetics	Thomson, A., 2004. Back to basics: pharmacokinetics. The Pharmaceutical Journal [online], vol 272. This article contains further explanations of basic pharmacokinetic concepts such as volume of distribution and steady-state. (This resource requires Adobe Reader.)
QMC Guide to antibiotic use	Guidelines registered with the Queen's Medical Centre, Nottingham University Hospitals NHS Trust (including information on antibiotic therapeutic drug monitoring), which represent local sensitivities and infection control issues.

Glossary

Adjusted body weight = ideal body weight + (0.4 * (actual body weight - ideal body weight). This equation accounts for the water content in adipose tissue, to allow more accurate gentamicin dosing in obese patients (those who are >20% above ideal body weight.); reference: Winter, M.E., 2004. Basic pharmacokinetics. London: Lippincott Williams and Williams.

Apparent volume of distributon: the volume of plasma necessary to account for the total amount of drug in the body, if it were present throughout the body at the same concentration found in the plasma.

Gram negative: a group of bacteria with a similar cell wall structure that prevents the uptake of a Gram stain.

Hartford Nomogram Dosing: a gentamicin dosing system used in some hospitals, where serum gentamicin level results are plotted on a graph against the time taken, post-dose. The result of the plot is used to determine the frequency of dosing. (See Hartford Nomogram link above.)

MIC: Minimum Inhibitory Concentration; the minimum concentration of antimicrobial required to inhibit the growth of a bacterium.

mRNA: messenger RNA; a section of genetic code containing information to produce a protein.

Post-antibiotic effect: some antibiotics continue to inhibit bacterial growth even after their concentration has fallen below the MIC; this is called a post-antibiotic effect.

Protein translation: the mechanism by which proteins are produced from amino acids by ribosomes using mRNA as the code.

Steady-state: when the amount of drug entering the body over a period equals the amount eliminated; in the
case of aminoglycosides, once steady-state is reached the patient's trough and peak levels will remain consistent.