The effective half-life of norfloxacin in serum and plasma is 3-4 hours.

With the decay constant it is possible to calculate the effective half-life using the formula:

Upon multiple dosing, it exhibits an effective half-life of accumulation of 12 hours.

See also: biological half-life, decay constant, effective half-life.

When the pharmacokinetics were studied in healthy human subjects, the peak concentration was achieved in 9 hours with effective half-life of approximately 17 hours .

The combined radioactive and biological half-life, called the effective half-life of the material, may range from hours for medical radioisotopes to decades for transuranic waste.

Effective half-life denotes the halving of radioactive material in a living organism by means of radioactive decay and biological excretion.

Rofecoxib crossed the placenta and blood-brain barrier, and took 1-3 hours to reach peak plasma concentration with an effective half-life (based on steady-state levels) of approximately 17 hours.

Effective half-life: the time required for the amount of a radionuclide deposited in a living organism to be diminished by 50% as a result of the combined action of radioactive decay and biologic elimination.

To the extent that prevention of neuronal destruction via DR-6 and N-APP would require ongoing intervention, the effective half-life of any monoclonal antibody treatment would have to be substantial.

To increase its effective half-life, trenbolone is not used in an unrefined form, but is rather administered as ester derivatives such as trenbolone acetate, trenbolone enanthate or trenbolone cyclohexylmethylcarbonate (Parabolan).

However, where there are few bony metastases, the large proportion of Sr not taken up by the bone will be filtered by the kidney, so that the effective half-life (a combination of the physical and biological half-life) will be much shorter.

Alternatively, since the radioactive decay contributes to the "physical (i.e. radioactive)" half-life, while the metabolic elimination processes determines the "biological" half-life of the radionuclide, the two act as parallel paths for elimination of the radioactivity, and in analogy with parallel resistors, the effective half-life could also be calculated by the formula: