It's not a sudden switch. It will gradually lose effectiveness over time.If it's still fighting your asthma the same as far as you can tell, it should still be good.But be sure to ask your doctor.
Ipratropium bromide (atrovent) and atropine sulfate are achticholinergic drugs used for the treatment of asthma. Ipratropium is used for treating asthmatics in emergency situations with a nebulizer
Both are considered bronchodilators but Albuterol increases respiratory rate and Ipratropium decreases it so to have the patient in a comfortable state.