Does This Method for Testing Inhaler Contents Still Float?

Dr Mohammed M. Basha's "Practical Pointer" recommendationthat patients determine how much medication is leftin their inhaler by placing the canister in a glass of water(CONSULTANT, April 1, 2003, page 502) is, unfortunately,not sound. Float tests are inaccurate and depend on whetherthe valve is up or down. In addition, the newer HFA canistersfloat when they are full. Patients can determine howmuch medication remains in the canister by keeping track ofthe number of puffs they have used. Instruct patients who usebudesonide or fluticasone propionate/salmeterol inhalers toread the counter window. The FDA now recommends thatall new inhalers (except dry-powder inhalers) be equippedwith counters.---- Yehia Y. Mishriki, MD
Professor of Clinical Medicine
Pennsylvania State University College of Medicine
Hershey
Most of my elderly patients use the oldercanisters, for which the method I describedworks well. Also, asking thesepatients--who already take at least adozen pills a day--to keep a log of thenumber of puffs they take is most impractical.---- Mohammed M. Basha, MD
Gainesville, Fla

References:

FOR MORE INFORMATION:

Brock TP, Wessell AM, Williams DM, Donohue JF. Accuracy of float testingfor metered-dose inhaler canisters. J Am Pharm Assoc (Wash). 2002;42:582-586.