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Pharmacokinetics of intravenous sildenafil in children with palliated single ventricle heart defects: effect of elevated hepatic pressures

Published online by Cambridge University Press:  01 April 2015

Kevin D. Hill*
Affiliation:
Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America The Duke Clinical Research Institute, Durham, North Carolina, United States of America
Mario R. Sampson
Affiliation:
The Duke Clinical Research Institute, Durham, North Carolina, United States of America University of North Carolina Eshelman School of Pharmacy, Chapel Hill, North Carolina, United States of America
Jennifer S. Li
Affiliation:
The Duke Clinical Research Institute, Durham, North Carolina, United States of America
Robert D. Tunks
Affiliation:
Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America
Scott R. Schulman
Affiliation:
Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, United States of America
Michael Cohen-Wolkowiez
Affiliation:
The Duke Clinical Research Institute, Durham, North Carolina, United States of America
*
Correspondence to: Dr K. D. Hill, MD, 7506 Hospital North, DUMC Box 3090, Durham, NC 27710, United States of America. Tel: +919.668.8305; Fax: +919.681.8927; E-mail: kevin.hill@duke.edu

Abstract

Aims

Sildenafil is frequently prescribed to children with single ventricle heart defects. These children have unique hepatic physiology with elevated hepatic pressures, which may alter drug pharmacokinetics. We sought to determine the impact of hepatic pressure on sildenafil pharmacokinetics in children with single ventricle heart defects.

Methods

A population pharmacokinetic model was developed using data from 20 single ventricle children receiving single-dose intravenous sildenafil during cardiac catheterisation. Non-linear mixed effect modelling was used for model development, and covariate effects were evaluated based on estimated precision and clinical significance.

Results

The analysis included a median (range) of 4 (2–5) pharmacokinetic samples per child. The final structural model was a two-compartment model for sildenafil with a one-compartment model for des-methyl-sildenafil (active metabolite), with assumed 100% sildenafil to des-methyl-sildenafil conversion. Sildenafil clearance was unaffected by hepatic pressure (clearance=0.62 L/hour/kg); however, clearance of des-methyl-sildenafil (1.94×(hepatic pressure/9)−1.33 L/hour/kg) was predicted to decrease ~7-fold as hepatic pressure increased from 4 to 18 mmHg. Predicted drug exposure was increased by ~1.5-fold in subjects with hepatic pressures ⩾10 versus <10 mmHg (median area under the curve=533 versus 792 µg*h/L).

Discussion

Elevated hepatic pressure delays clearance of the sildenafil metabolite – des-methyl-sildenafil – and increases drug exposure. We speculate that this results from impaired biliary clearance. Hepatic pressure should be considered when prescribing sildenafil to children. These data demonstrate the importance of pharmacokinetic assessments in patients with unique cardiovascular physiology that may affect drug metabolism.

Type
Original Articles
Copyright
© Cambridge University Press 2015 

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Footnotes

*

Equal contributors.

References

1. Jackson, SP. Sensing and repairing DNA double-strand breaks. Carcinogenesis 2002; 23: 687696.Google Scholar
2. Gewillig, M. The Fontan circulation. Heart 2005; 91: 839846.Google Scholar
3. Narkewicz, MR, Sondheimer, HM, Ziegler, JW, et al. Hepatic dysfunction following the Fontan procedure. J Pediatr Gastroenterol Nutr 2003; 36: 352357.Google Scholar
4. Rychik, J, Veldtman, G, Rand, E, et al. The precarious state of the liver after a Fontan operation: summary of a multidisciplinary symposium. Pediatr Cardiol 2012; 33: 10011012.Google Scholar
5. Wu, FM, Ukomadu, C, Odze, RD, et al. Liver disease in the patient with Fontan circulation. Congenit Heart Dis 2011; 6: 190201.CrossRefGoogle ScholarPubMed
6. Baek, JS, Bae, EJ, Ko, JS, et al. Late hepatic complications after Fontan operation; non-invasive markers of hepatic fibrosis and risk factors. Heart 2010; 96: 17501755.Google Scholar
7. Gentles, TL, Gauvreau, K, Mayer, JE Jr., et al. Functional outcome after the Fontan operation: factors influencing late morbidity. J Thorac Cardiovasc Surg 1997; 114: 392403; discussion 404–395.Google Scholar
8. Beghetti, M. Fontan and the pulmonary circulation: a potential role for new pulmonary hypertension therapies. Heart 2012; 96: 911916.Google Scholar
9. Goldberg, DJ, Shaddy, RE, Ravishankar, C, et al. The failing Fontan: etiology, diagnosis and management. Expert Rev Cardiovasc Ther 2011; 9: 785793.Google Scholar
10. Reinhardt, Z, Uzun, O, Bhole, V, et al. Sildenafil in the management of the failing Fontan circulation. Cardiol Young 2010; 20: 522525.Google Scholar
11. Uzun, O, Wong, JK, Bhole, V, et al. Resolution of protein-losing enteropathy and normalization of mesenteric Doppler flow with sildenafil after Fontan. Ann Thorac Surg 2006; 82: e39e40.Google Scholar
12. Walker, DK, Ackland, MJ, James, GC, et al. Pharmacokinetics and metabolism of sildenafil in mouse, rat, rabbit, dog and man. Xenobiotica 1999; 29: 297310.Google Scholar
13. Muirhead, GJ, Wilner, K, Colburn, W, et al. The effects of age and renal and hepatic impairment on the pharmacokinetics of sildenafil. Br J Clin Pharmacol 2002; 53 (Suppl 1): 21S30S.Google Scholar
14. Medical, Statistical, and Clinical Pharmacology Reviews of Pediatric Studies Conducted under Section 505A and 505B of the Federal Food, Drug, and Cosmetic Act, as amended by the FDA Amendments Act of 2012 (FDASIA). Retrieved August 3, 2014, from http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/ucm316937.htm Google Scholar
15. Barst, RJ, Ivy, DD, Gaitan, G, et al. A randomized, double-blind, placebo-controlled, dose-ranging study of oral sildenafil citrate in treatment-naive children with pulmonary arterial hypertension. Circulation 2011; 125: 324334.Google Scholar
16. Hill, KD TR, Barker, P, Fleming, GA, et al. Sildenafil exposure and hemodynamic effect after stage II single ventricle surgery. Pediatr Crit Care Med 2014; 15: 2834.Google Scholar
17. Hill, KD, Tunks, RD, Barker, PC, et al. Sildenafil exposure and hemodynamic effect after stage II single-ventricle surgery. Pediatr Crit Care Med 2013; 14: 593600.Google Scholar
18. Mukherjee, A, Dombi, T, Wittke, B, et al. Population pharmacokinetics of sildenafil in term neonates: evidence of rapid maturation of metabolic clearance in the early postnatal period. Clin Pharmacol Ther 2009; 85: 5663.Google Scholar
19. Muirhead, GJ, Rance, DJ, Walker, DK, et al. Comparative human pharmacokinetics and metabolism of single-dose oral and intravenous sildenafil. Br J Clin Pharmacol 2002; 53 (Suppl 1): 13S20S.Google Scholar
20. Vachiery, JL, Huez, S, Gillies, H, et al. Safety, tolerability and pharmacokinetics of an intravenous bolus of sildenafil in patients with pulmonary arterial hypertension. Br J Clin Pharmacol 2011; 71: 289292.Google Scholar
21. Nichols, DJ, Muirhead, GJ, Harness, JA. Pharmacokinetics of sildenafil after single oral doses in healthy male subjects: absolute bioavailability, food effects and dose proportionality. Br J Clin Pharmacol 2002; 53 (Suppl 1): 5S12S.Google Scholar
23. Marsot, A, Boulamery, A, Bruguerolle, B, et al. Population pharmacokinetic analysis during the first 2 years of life: an overview. Clin Pharmacokinet 2012; 51: 787798.Google Scholar
24. Laughon, MM, Benjamin, DK Jr., Capparelli, EV, et al. Innovative clinical trial design for pediatric therapeutics. Expert Rev Clin Pharmacol 2011; 4: 643652.Google Scholar
25. Ku, LC, Smith, PB. Dosing in neonates: special considerations in physiology and trial design. Pediat Res 2015; 77(1-1): 29.Google Scholar
26. Valitalo, P, Ranta, VP, Hooker, AC, et al. Population pharmacometrics in support of analgesics studies. Acta Anaesthesiol Scand 2014; 58: 143156.CrossRefGoogle ScholarPubMed
27. Goldberg, DJ, French, B, McBride, MG, et al. Impact of oral sildenafil on exercise performance in children and young adults after the fontan operation: a randomized, double-blind, placebo-controlled, crossover trial. Circulation 2011; 123: 11851193.CrossRefGoogle Scholar
28. Giardini, A, Balducci, A, Specchia, S, et al. Effect of sildenafil on haemodynamic response to exercise and exercise capacity in Fontan patients. Eur Heart J 2008; 29: 16811687.Google Scholar
29. Food and Drug Administration Drug Safety Communication. Retrieved December 9, 2013, from http://www.fda.gov/Drugs/DrugSafety/ucm317123.htm Google Scholar
30. European Medicines Agency Science Medicines Health Assessment report for Revatio. Retrieved January 20, 2014, from http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Assessment_Report_-_Variation/human/000638/WC500107804.pdf Google Scholar
31. US Department of Health and Human Services, Food and Drug Administration. Guidance for industry. population pharmacokinetics. Retrieved August 3, 2014, from http://www.fda.gov/downloads/ScienceResearch/SpecialTopics/WomensHealthResearch/UCM133184.pdf.Google Scholar
32. Guideline on the role of pharmacokinetics in the development of medicinal products in the paediatric population (2006). Retrieved October 1, 2014, from http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2009/09/WC500003066.pdf Google Scholar