Tingling sensation in my upper chest, and pain in upper back when coughing. i have asthma, am on montelukast, and use an inhaler. should i be worried?

Yes: This may indicate that your asthma is not under good control . Monetlukast works on only about 50% of the people and may not be enough even if it is effective. You need to see your doctor to find out if an inhaled steroid +/- a long-acting bronchodilator may be a better choice. Do note that tobacco smoking often makes anti-asthma treatment less effective.