May 30, 2008 - 3:34 p.m.

WASHINGTON (AP) - Old-fashioned asthma inhalers that contain environment-harming chemicals will no longer be sold at year's end — and the government is urging patients not to wait until the highest minute to switch to newer alternatives.

Patients practice inhalers to dispense airway-relaxing albuterol during asthma attacks.

Chemicals called chlorofluorocarbons, or CFCs, formerly were widely used to propel the drug into the lungs. But CFC-containing consumer products are being phased out because CFCs damage the Earth's protective ozone layer. As of Dec. 31, asthma inhalers through CFCs can no longer subsist made or sold in the U.S. Inhalers instead will be powered by ozone-friendly HFAs, or hydrofluoroalkanes.

The ozone layer shields the planet from harmful ultraviolet radiation.

Patients have been warned of the change for several years, but the Food and Drug Administration issued an advisory Friday saying anyone still using CFC inhalers should ask their physician about switching now.

The FDA warns that patients will effrontery a attainments curve: HFA inhalers may taste and feel different. The spray may feel softer. Each must be primed and cleaned in a specific way to prevent clogs. And they tend to require to be paid additional.

CFC-free albuterol inhaler options include GlaxoSmithKline's Ventolin HFA, Schering Plough's Proventil HFA and Teva Specialty Pharmaceuticals' ProAir HFA. Sepracor's Xopenex HFA is also CFC-free, but it contains levalbuterol, a resembling medication.

The FDA said Armstrong Pharmaceuticals is the sole remaining maker of CFC inhalers and is expected to stop production unruffled before the deadline. A spokesman for Armstrong's parent company wouldn't say when production would stop, but sales of remaining inventory will tarry until Dec. 31.

(This interpretation SUBS 6th graf to correct ProAir maker; SUBS final graf with Armstrong comment.)