Greetings Johnny Mac
Welcome to the parkinson's medication merry go round. You will find that you MUST do your own research on meds.
For example- Do NOT mix those two meds- there is a real danger of serotonin syndrome if you do. See info below and find some good medical research websites for yourself to do your research on.
I took Selegeline, 10mg. divided into two doses of 5mg each, morning and night for 12-13 years when I was first diagnosed in 1997. I believe it slowed the progression of the disease- for me. I was hospitalized twice during that period for drug interaction and was always worried that if I was in an accident that the MAO-I (selegeline) mixed with some random drug they might give me in the hospital would kill me. I should have gotten a medical bracelet to wear.
Although I didn't take it for depression, I have never been less depressed in my life than when I was taking selegeline.
I stopped taking it 5 years ago when I started on sinemet.
Good luck with your journey- it seems your instincts are good.
Victoria

Interactions between your selected drugs

selegiline ↔ venlafaxine
Applies to:Emsam (selegiline) and venlafaxine
Using selegiline together with venlafaxine is not recommended. Combining these medications can increase the risk of a rare but serious condition called the serotonin syndrome, which may include symptoms such as confusion, hallucination, seizure, extreme changes in blood pressure, increased heart rate, fever, excessive sweating, shivering or shaking, blurred vision, muscle spasm or stiffness, tremor, incoordination, stomach cramp, nausea, vomiting, and diarrhea. Severe cases may result in coma and even death. In general, you should wait at least 14 days after stopping selegiline before you start treatment with venlafaxine. Conversely, if you have recently been on venlafaxine and are now starting treatment with selegiline, you should check with your doctor or pharmacist to see how long you should wait before it is safe for you to use selegiline, as some antidepressants can take a while to clear from your body. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.