Improvement ofdrugdelivery withabreath actuated pressurised aerosol forpatients withpoor inhaler technique

Background Themetereddoseinhaler is difficult tousecorrectly, synchronising actuation withinhalation beingthemost important problem. A breathactuated pressurised inhaler, designedto help patients withpoorinhaler technique, was comparedwith a conventional metereddoseinhaler intermsofaerosol deposition andbronchodilator response. MethodsRadioaerosol deposition and bronchodilator responseto100pgsalbutamol weremeasuredin18asthmatic patients, who inhaled froma conventional metereddoseinhaler bytheir own chosenmetereddoseinhaler technique, from a conventional metereddose inhaler byataught metereddoseinhaler technique, andfroma breathactuated pressured inhaler (Autohaler). Results Inthe10patients who could coordinate actuation andinhalation of theinhaler on theirown deposition of aerosol inthelungsandbronchodilator response wereequivalent on thethree studydays.By contrast, intheeight patients who couldnotcoordinate the mean (SEM)percentage of thedose deposited inthelungswiththeirown inhaler technique (7-2%(3-4%)) wassubstantial lowerthanthoseattained bythe taught metereddoseinhaler technique (22-8%(2-5%)) andbyAutohaler (20-8% (1P7%)). Although oflittle additional benefit toasthmatic patients withgood coordination, theAutohaler ispotentially a valuable aidtothosewithpoor coordination, andshouldbeconsidered inpreference toaconventional metered doseinhaler inanypatient whoseinhaler technique isnotknowntobesatisfactory.