Table 2.

Pharmacokinetic comparison of different dosage regimens of levonorgestrel

Study (year)	Dose	P k parameters								Side effects
		AUC 0–12 (ng-h/ml)	AUC 0–24 (ng-h/ml)	AUC 0-t (ng-h/ml)	AUC 0-∞ (ng-h/ml)	C max (ng/ml)	t max (h)	K el (1/h)	t 1/2 (h)
Gainer et al., (2007) [28]	1.5 mg	28.6	45.0	252.8	262.6	15.4	2.0	----	29.3	----
Johansson et al., (2002) [23]	0.75 mg & 1.5 mg	A:49.9	A:81.3	A:139.5	----	A:7.9	A:1.8	----	A:43.7	Nausea, sleepiness, headache.
		B:51.9	B:73.2	B:136.0		B:8.4	B:1.4		B:32.0
		C:88.8	C:130.8	C:290.9		C:12.4	C:2.5		C:43.3
Kook et al., (2002) [24]	0.75 mg	----	----	111.8	123.1	14.1	1.63	0.030	24.4	Menstrual irregularity
Sambol et al., (2006) [29]	0.75 mg	----	----	----	86.1	6.72	1.43	----	21.2	Headaches, dizziness, nausea, cramps
Tremblay et al., (2001) [25]	0.75 mg	----	----	----	133.02	----	2.27	0.042	21.72	----

AUC_0-t: Area under the plasma concentration time curve calculated by the trapezoidal rule from time 0 until the last time point.

AUC_0-∞: Area under the plasma concentration time curve corrected for the previous administration and extrapolated to infinity.

A: One tablet of 0.75 mg levonorgestrel at time −12 h and one tablet at time 0.

B: One tablet of 0.75 mg levonorgestrel at time 0.

C: One tablet of 0.75 mg levonorgestrel at time −24 h and one tablet at time 0.