Thanks for your question on HCM. I can understand your situation and problem. Azithromycin is antibiotic and not cough suppressant. Benzonatate Is cough suppressant. But nowadays more effective and less sedative cough suppressant s are available in the market. Newer antihistamines are Very good cough suppressant. Methyl prednisolone is oral steroid and should not be given regularly unless strongly indicated. So better to consult pulmonologist and get done PFT (pulmonary function test) to rule out bronchitis. And also discuss about newer cough suppressant. Since these are prescribed drugs, you will need prescription for this.