Læknablaðið : fylgirit - 01.05.1978, Page 59

Fig. 2 Naproxen plasma
levels (ug/ml) mean -
S.D. Daily dosage:
10,4 * 1 mg/kg
(280 ± 30 mg/m2).
Morning samples.
pg/ml Naproxen plasma levels (pg / ml) mean - S.D.
Fig. 3 Fluctuation of the
plasma levels during
the steady state.
It can be expected two
peaks in plasma
levels during every
twenty-four hours
provided that the drug
is administered twice daily.
pg/ml Naproxen plasma levels (pg/ml)
and by determining naproxen and its metabolite
demethylated naproxen in urine, both of them
separately in conjugated and unconjugated forms.
Figure 1.: At the beginning of the test, the
very first tablet was administered at 8 o clock
in the morning, after breakfast. The peak
plasma level was reached on an average four
hours after ingesting naproxen tablets. Similar
results are reported by Runkel et al. (3) in
adults after oral administration of naproxen under
non-fasting conditions.
Figure 2.: In morning samples, the plasma
levels increased slightly until the fourth day of
the treatment. After that, the steady state was
reached, and the plasma levels in morning
samples were maintained within a narrow range.
This result corresponds to that in adults. In
adult patients, it takes about three days for a
plasma level equilibrium to be established. (4,5)
After fourteen days the medication was
discontinued. Twenty four hours after the intake
of the last tablet, the mean plasma level was
approximately 50 per cent of that observed in
the morning samples during the steady state.
During the steady state (Figure 3) on the
fifth and tenth days, blood samples were taken
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