<s>[INST] I am  having  whooping type of cough.  ihave been told by chest physician  it is allergic.        i am suffering since 2 months. recntly i have been put on telecast f tabs  sice 4 days.     . how long it takes to act.  and how long i have to take this [/INST] hello,thanks for ur query,2months old cough should be evaluated with xray chest  and blood tests. telecasdt-f tablet used in prevention of allergic rhinits and asthma.it should be taken for 4-6moths and tapered slowly depanding on ur symptoms.u need to see an ent surgeon for farthur evaluation and treatment.all d best.take care. </s>