Why consider PIFR in COPD patients?

 

Why can PIFR be a concern with a dry powder inhaler (DPI) for COPD patients?

  • DPIs rely on inspiratory flow
  • Low PIFR may lead to marked reductions in*
    • Fine particles/emitted dose reaching the lungs1-3
    • Lung deposition4,5



  • Most DPI devices require a minimum PIFR 30 L/min6,8,9
  • PIFR > 60 L/min may help to maximize drug delivery*6,8,9

* Based on studies designed to measure inspiratory flow rates and drug delivery at different levels of resistance. These studies were not designed to evaluate efficacy and safety.

Nebulized therapy may be the right fit

References:

1. Al-Showair RAM, Tarsin WY, Assi KH, Pearson SB, Chrystyn H. Can all patients with COPD use the correct inhalation flow with all inhalers and does training help? Respir Med. 2007;101(11):2395-2401. 2. Virchow JC, Crompton GK, Dal Negro R, et al. Importance of inhaler devices in the management of airway disease. Respir Med. 2008;102(1):10-19. 3. Prime D, Grant AC, Slater AL, Woodhouse RN. A critical comparison of the dose delivery characteristics of four alternative inhalation devices delivering salbutamol: pressurized metered dose inhaler, Diskus inhaler, Diskhaler inhaler, and Turbuhaler inhaler. J Aerosol Med. 1999;12(2):75-84. 4. Borgstrõm L, Bondesson E, Morén F, Trofast E, Newman SP. Lung deposition of budesonide inhaled via Turbuhaler®: a comparison with terbutaline sulphate in normal subjects. Eur Respir J. 1994;7(1):69-73.5. Derom E, Strandgården K, Schelfhout V, Borgstrõm L, Pauwels R. Lung deposition and efficacy of inhaled formoterol in patients with moderate to severe COPD. Respir Med. 2007;101(9):1931-1941.6. Jarvis S, Ind PW, Shiner RJ. Inhaled therapy in elderly COPD patients; time for re-evaluation? Age Ageing. 2007;36(2):213-218. 7. Everard ML, Devadason SG, Le Soüef PN. Flow early in the inspiratory manoeuvre affects the aerosol particle size distribution from a Turbuhaler. Respir Med. 1997;91(10):624-628. 8. Janssens W, VandenBrande P, Hardeman E, et al. Inspiratory flow rates at different levels of resistance in elderly COPD patients. Eur Respir J. 2008;31(1):78-83. 9. Broeders MEAC, Molema J, Vermue NA, Folgering HTM. In Check Dial: accuracy for Diskus and Turbuhaler. Int J Pharm. 2003;252(1-2):275-280. 10. Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease (2010). http://www.goldcopd.org. Accessed March 15, 2011. 11. Dolovich MB, Ahrens RC, Hess DR, et al. Device selection and outcomes of aerosol therapy: evidence-based guidelines. Chest. 2005;127(1):335-371.