L. J. Scott and C. M. Perry, Tramadol: a review of its use in perioperative pain, Drugs, vol.60, pp.139-76, 2000.

P. Bozkurt, Use of tramadol in children, Paediatr Anaesth, vol.15, pp.1041-1048, 2005.

W. Lintz, H. Barth, R. Becker, E. Frankus, and E. Schmidt-bothelt, Pharmacokinetics of tramadol and bioavailability of enteral tramadol formulations. 2nd communication: drops with ethanol, Arzneimittelforschung, vol.48, pp.436-481, 1998.

H. H. Hennies, E. Friderichs, and J. Schneider, Receptor binding, analgesic and antitussive potency of tramadom and other selective opioids, Arzneim Forsch/Drug Res, vol.38, pp.877-80, 1988.

G. Quetglas, E. Azanza, J. R. Cardenas, E. Sadaba, B. Campanero et al., Stereoselective pharmacokinetic analysis of tramadol and its main phase I metabolites in healthy subjects after intravenous and oral administration of racemic tramadol, Biopharm Drug Dispos, vol.28, pp.19-33, 2007.

R. S. Pedersen, P. Damkier, and K. Brosen, Enantioselective pharmacokinetics of tramadol in CYP2D6 extensive and poor metabolizers, Eur J Clin Pharmacol, vol.62, pp.513-534, 2006.

S. H. Gan, R. Ismail, W. Adnan, W. A. Zulmi, W. Jelliffe et al., Population pharmacokinetic modelling of tramadol with application of the NPEM algorithms, J Clin Pharm Ther, vol.29, pp.455-63, 2004.

H. C. Liu, T. J. Liu, Y. Y. Yang, and Y. N. Hou, Pharmacokinetics of enantiomers of trans-tramadol and its active metabolite, trans-O-demethyltramadol, in human subjects, Acta Pharmacol Sin, vol.22, pp.91-97, 2001.

S. Liao, J. F. Hill, and R. K. Nayak, Pharmacokinetics of tramadol following single and multiple oral doses in man, Pharm Res, vol.9, p.308, 1992.

B. V. Murthy, K. S. Pandya, P. D. Booker, A. Murray, W. Lintz et al., Pharmacokinetics of tramadol in children after i.v. or caudal epidural administration, Br J Anaesth, vol.84, pp.346-355, 2000.

K. Allegaert, B. J. Anderson, and R. Verbesselt, Tramadol disposition in the very young: an attempt to assess in vivo cytochrome P-450 2D6 activity, Br J Anaesth, vol.95, pp.231-240, 2005.

M. J. Garrido, W. Habre, F. Rombout, and I. F. Troconiz, Population pharmacokinetic/pharmacodynamic modelling of the analgesic effects of tramadol in pediatrics, Pharm Res, vol.23, pp.2014-2037, 2006.

J. Zwaveling, S. Bubbers, and A. H. Van-meurs, Pharmacokinetics of rectal tramadol in postoperative paediatric patients, Br J Anaesth, vol.93, pp.224-231, 2004.

K. A. Payne, J. A. Roelofse, and E. A. Shipton, Pharmacokinetics of oral tramadol drops for postoperative pain relief in children aged 4 to 7 years-a pilot study, Anesth Prog, vol.49, pp.109-121, 2002.

K. Allegaert, J. N. Van-den-anker, and J. N. De-hoon, Covariates of tramadol disposition in the first months of life, Br J Anaesth, vol.100, pp.525-557, 2008.

D. Patti, F. Fanelli, D. Pedersen, R. S. Giuliani, C. Torricelli et al., Modelling the pharmacokinetics of tramadol: on the difference between CYP2D6 extensive and poor metabolizers, J Theor Biol, vol.254, pp.568-74, 2008.

W. Büttner and W. Finke, Analysis if behavioural and physiological parameters for the assessment of post operative analgesic demand in newborns, infants and young children: a comprehensive report on seven consecutive studies, Paediatr Anaesth, vol.10, pp.303-321, 2000.

S. L. Beal and L. B. Sheiner, NONMEM User's Guide, 1994.

, Research Development Population Pharmacokinetics. Visual-NM User's Manual, version 5.1, Research Development Population Pharmacokinetics, 1998.

A. Sundhine, A new clinical experience with tramadol, Drugs, vol.47, pp.8-18, 1994.

T. A. Bamigbade and T. M. Langford, The clinical use of tramadol hydrochloride, Pain Rev, vol.5, pp.155-82, 1998.

, Tramadol enantiomers in children