DRUG LEVELS (THERAPEUTIC DRUG MONITORING)

Για τον καθορισμό της δόσης μιας χορηγούμενης φαρμακευτικής ουσίας θα πρέπει τα επίπεδα του φαρμάκου στο πλάσμα να παραμένουν εντός των θεραπευτικών ορίων. For determining a dose of an administered drug substance, the drug levels in plasma should remain within therapeutic range. Otherwise lower concentrations than the minimum concentration (Cmin) lead to failure of therapeutic treatment, while concentrations higher than the maximum concentration (Cmax) lead to side effects.

Usually recommended dosage is based on pharma cokinetic studies in a small population of normal adult animals. Most of these substances are administered to patient als, whose absorption, distribution, metabolism, excretion or the combination of the above are affected by normal factors (eg. breed, age) pathological (eg_renal, liver malfunction) or pharmacological (e.g. interactions of pharmaceutical substances).

The result of the above is the determination of higher or lower drug levels than the expected Consequently it is considered necessary to check in every case the concentrations of the pharmaceutical substances and adjust doses in order to ensure the effectiveness and safety of therapeutic treatment.

PHENOBARBITAL

It is proposed to determine the levels of Phenobarbital 14, 45, 90, 180 and 360 days from the onset of the treatment. Afterwards semi-annual checks are suggested. In cases that an amendment of the initial dosage is required, a recheck is recommended on the basis of the above timetable.

At the same time it would be good, especially in long term treatments, to measure ALT ALP, YGT, Albumin and Bilirubin as indicators of liver function. Cmin is measured about 1 hour before administered dose.

Cmin is measured about 1 hour before administered dose.

Cmax is measured 4 to 5 hours after the administered dose.

Half-life time is 32 to 75 hours.

Serum is required.

DIGOXIN

It is proposed to determine the levels of Digoxin at least 5 to 7 days from the start of the treatment. In cases that an amendment of the initial dosage is required, a measurement of 2 samples for the determination of maximum and minimum concentration in serum is recommended. Furthermore it is important to check the the function of kidneys, of liver and the proportion of Na K.

Cmin is measured about 1 hour before administered dose.

Cmax is measured 3 to 5 hours after the administered dose.

Half-life time is 12 to 33 hours

Serum is required.

Please label the samples according to the time of collection. The laboratory upon request is giving the appropriate information after the export of results.