Peer reviewed clinical letter
		
		
			Vol. 145 No. 3132 (2015)
		
		
			Stop using the flotation technique and start weighing salbutamol pressurised metered-dose inhalers without dose counters
		
							
				
											- Ermindo R. Di Paolo
 
											- Stéphanie Spaggiari
 
											- André Pannatier
 
											- Farshid Sadeghipour
 
											- Isabelle Rochat
 
											- Gaudenz  M Hafen
 
									
			 
												
				
	
	
		
			- 
				Cite this as:
			
 
			- 
			Swiss Med Wkly. 2015;145:w14162
			
 
							- 
					Published
				
 
				- 
																26.07.2015
														
 
							
		
	 
				Summary
		Salbutamol pressurised metered-dose inhalers (pMDIs) are not equipped with dose counters outside the USA. The aim of this study was to describe a simple reproducible method for determining the number of doses remaining in a pMDI based on scale weight. With a laboratory scale, the mean weight of the canisters was 28.61 ± 0.10 g after priming and 14.84 ± 0.23 g after 200 puffs. Similar results were obtained with two common digital scales. We recommend weighing salbutamol canisters on a common digital scale, and replacing an old pMDI with a new one when the weight falls to ≤15 g.
	
				
			References
		
					
									- Sander N, Fusco-Walkert SJ, Harder JM, Chipps BE. Dose counting and the use of pressurised metered-dose inhalers: running on empty. Ann Allergy Asthma Immunol. 2006;97(1):34–8. 
 
									- Ogren RA, Baldwin JL, Simon RA. How patients determine when to replace their metered-dose inhalers. Ann Allergy Asthma Immunol. 1995;75(6):485–9. 
 
									- Brock TP, Wessell AM, Williams DM, Donohue JF. Accuracy of float testing for metered-dose inhaler canisters. J Am Pharm Assoc (Wash.). 2002;42(4):582–6. 
 
									- Rubin BK, Durotoye L. How do patients determine that their metered-dose inhaler is empty? Chest. 2004;126(4):1134–7. 
 
									- Conner JB, Buck PO. Improving asthma management: The case for mandatory inclusion of dose counters on all rescue bronchodilators. J Asthma. 2013;50(6):658–63.