Hi,
Your father is having asthma,arthritis( both
knee pain),HTN and IHD with 68 years age.
First,you can continue treatment for asthma like inhalers ( MDI or Rotacap) of steriods,alpha agonists, anticholinergics etc.
I have assumed arthritis for knee pain,so you can take treatment from orthopedician after confirmed diagnosis.
Now,if he has old history of inferior wall MI with
hypertension then you can continue antihypertensive, antiplatelets or anticoagulants
(
ecosprin,
clopidogrel or heparin),hypolipidemics( statins or fibrates),antiarrhythmic if required etc but after the consultation of cardiologist.
His prognosis will mainly depend on his cardiac
ejection fraction (EF- on 2D echo)and its activity during rest and exertion.
So,better you do a regular follow-up at cardiologist every 6 monthly at least.
Other factors are not a big issue in an otherwise healthy individual.He can continue with the treatment.