I have asthma and been perscribed a controller inhaler recently. It is expensive and I would like to cut back on the usage of the inhaler. Can i?

Need doctor... A controller asthma medicine is frequently used to decrease the amount of lung inflammation, which reliever meds don't do. A controller med must be taken all the time to work, not just when you have symptoms. Even though they may be expensive, if it prevents an acute episode and prevents an er visit, it is actually saving money in the long run. See your doctor before you reduce dose or stop meds.
How severe? If you have moderate or severe persistent asthma you are best advised to remain on controller medications. If cost is an absolute problem consider getting medication from canada. Alternate day oral Prednisone is effective & cheap but may be riskier than inhaled drugs. Some patients with mild persistent asthma may be controlled with controller meds only for exacetbations. Talk to your md.
Asthma. Asthma control is often measured by how often a rescue inhaler is needed -- the decision to cut back dosing on a controller inhaler should be made in conjunction with your prescribing physician, but this is possible in certain circumstances.