74, if the pain is really bad, take a very large dose three times a day. A high doses for short term will not be harmful at all, but will give you an idea very quickly if Serratiopeptidase will work in your situation. You can lower the dose later for a maintenance dose.
BUT don’t stop there! You MUST find what is causing the inflammation and stop it. The source might be vibration or repetitive strain injury, complication or undiagnosed diabetes (pre-diabetes, metabolic syndrome or obesity), rheumatoid arthritis, or some other cause. (If it turns out to be diabetes or RA, I can give you some leads that you can follow up with research.)
Serratiopeptidase is just a band-aid. It will give some pain-free time to find the root of the problem.
I am very fond of dietary solutions to chronic health problems because getting my diet right solved all my health problems included asthma, allergies, chronic sinus infections, yeast infections, osteoarthritis and epilepsy. I was in chronic pain for over six years. All these “illnesses” are just symptoms of chronic inflammation. If I hadn’t changed my ways, I was on the road to some horrible, health crisis.
Good luck, and keep us posted as to how your dad is doing.