Inhalation Therapy. Inhalation Therapy

Transcription

1 Matching Device and Patient Matching Patient to the Device Søren Pedersen University of Southern Denmark Kolding Hospital Anatomical factors (age) Training and education Delivered dose Psycomotor skills Particle size Inhaler preference? Ease of use Compliance Inhalation technique

2 Variations Inhaler Bench Sophisticated models The inhaler with the best in-vitro characteristics may not be the preferred for all patients in daily clinical use Lung deposition studies Clinical studies Every day use In vitro In vivo Adherence Inh. Technique etc. Fine Particle Mass Dry Powder Inhalers Fine particle size distribution: Diskos Peak Inspiratory Flow (L/min) Particles 5-2 µm Particles <2 µm (Bisgaard et al, ERJ, 1998)

3 Dry Powder Inhalers Lung deposition and inspiratory flow rate Mean AUC (pg.h/ml) Individual Large inter and intra-subject variation but little in-vitro variation Inspiratory flow rate through Diskus (L/min) (Agertoft 1999) Matching Device and Patient No single inhaler will satisfy the needs of all patients Which considerations are important when matching patient and device?

4 Matching Device and Patient Ease of use Important Considerations Simple inhalation technique Convenience Drug delivered Price In-vitro characteristics >100 different inhaler/drug combinations are available. It may be better for a clinician to focus This on increases a limited the number likelihood of finding inhalers an appropriate to get better inhaler It also increases experience complexity with and the health-providers devices used experience with each individual inhaler Most frequently used devices Pressurized metered dose inhalers (pmdi) CFC and HFA Breath-activated Spacer devices Dry powder inhalers (DPI) Nebulizers What s the most frequently used inhalers?

5 Retail sales of inhalation devices in Europe DPIs are the most commonly used in Europe, but marked differences are seen between countries Worldwide pmdis are the most commonly used Lavorini et al Respir Med (accepted for publication) Retail sales of inhalation devices in Europe Prescriptions vary with the drug used Lavorini et al Respir Med (accepted for publication)

6 No exhalation Coordination Fast insp No breath hold Cold Freon Nose insp Shallow insp (Pedersen S, Allergy 1986;41: ) Common problems with pmdis No shaking Less than 50% of patients on regular treatment with a pmdi use it correctly No exhalation prior to inspiration Co-ordination problems Optimal The inspiratory mistakes flow are similar in children and in adults, but generally more common Bronchoconstriction in younger age groups (lubricants and and elderly CFCs) people Cold freon effect Inhalation through the nose

7 Common problems with pmdis No shaking in Children No exhalation prior to inspiration Co-ordination problems Optimal inspiratory flow Bronchoconstriction (lubricants and CFCs) Cold freon effect HFA pmdi s Inhalation through the nose

8 in Children Most frequently used devices Pressurized metered dose inhalers (pmdi) CFC and HFA Spacer devices Dry powder inhalers (DPI) Nebulizers in Children Common problems with pmdis No shaking Effect of spacers No exhalation prior to inspiration Co-ordination problems Optimal inspiratory flow Bronchoconstriction (lubricants and CFCs) Cold freon effect Inhalation through the nose

9 Main problems with spacers Inconvenient Air leakage around mouth-piece/face mask In young children differences in valve system, face mask, Multiple dead actuations space and spacer volume are important plus which pmdis that Delay can be between used with actuation the spacer and inhalation Shallow inhalations Static electricity (device dependent) in Children Most frequently used devices Pressurized metered dose inhalers (pmdi) CFC and HFA Spacer devices Dry powder inhalers (DPI) Nebulizers

10 PIFR (l/min) Pedersen et al, 1996 PIF through Turbuhaler in 265 children After demonstration After 2 corrections Age (years)

11 L/min Inpiratory flow profiles through a DPI Inhaled volume (L) Flow [l/min] ,2 0,4 0,6 0,8 1,0 Time [sec]

12 in Children Common problems with pmdis Effect DPI s No shaking No exhalation prior to inspiration Co-ordination problems Optimal inspiratory flow Bronchoconstriction (lubricants and CFCs) Cold freon effect Inhalation through the nose Main problems with DPI s Exhalation Various through inhalers the inhaler have (device different dependent) design, strengths and weaknesses. This Insufficient inspiratory flow rate (device dependent) facilitates individualized therapy. Loading difficulties (device dependent) Slow-start inhalation profile (device dependent) Humidity (device dependent) Dose counter (device dependent)

13 in Children Inhaler Preference Inhaler preference studies are generally unreliable The device of the sponsoring company is always preferred The importance of inhaler preference for compliance and adherence is not known Matching Device and Patient Summary The development of better inhalers has made effective drug delivery to the lungs possible in the majority of patients The main reasons for treatment failure are poor inhaler use and adherence with therapy The poor What inhaler can use we use can for be our markedly daily choices? reduced by: Choosing the right inhaler for the individual patient Careful and repeated tuition and check of correct inhaler use at regular intervals

14 Matching Device and Patient Correct inhaler use > 90% of time % of patients With the currently available devices virtually all children can be taught effective Inhaler use DPI Nebulizer Spacer QVAR pmdi Different age groups require different devices Age (years) (Pedersen S et al. Prim Care Respir J. 2010; 19(3):209-16) Matching Device and Patient Likelihood of correct inhaler use after tuition High Spacer Nebulizer DPI BA-pMDI Spacer Spacer Nebulizer Nebulizer BA-pMDI Medium DPI pmdi DPI How can the current results be improved? Low BA-pMDI pmdi pmdi < 6 years 6 65 years > 65 years

15 Anatomical factors (age) Training and education Delivered dose Psycomotor skills Particle size Inhaler preference? Ease of use Compliance Inhalation technique The medical community must ensure a setup which guaranties regular check and reinforcement of inhalation technique Easier and more convenient inhaler use and more simple inhalation techniques require improved/new inhalers and better understanding of the importance of each recommendation given about correct inhalation technique Levy M et al ERS 2010

16 Welcome technical developments MDIs Dose counters and adherence monitoring More breath-actuated devices Teaching Focus aids and should feed-back be systems redirected from in-vitro characterization to production and DPIs assessment of which inhalers are easiest to Dose use counters correctly and adherence by various monitoring groups of patients and the importance of the individual does not affect steps dosing inhalation or particle sizeinstructions Inhalers in which exhalation through the device prior to inhalation Devices which do not release the dose until a sufficient inspiratory flow rate has been reached Teaching and handling aids (latter mainly for elderly and arthritis)