The following experience was frightening and negative, and even the next day I felt a little troubled. I don't want to suggest that this combination of Modafinil and Phenibut was solely responsible for what happened, as it may have simply been due to my lack of hydration. I only want to provide a little food for thought.
As you'll read below, I experienced "ear pressure fluctuations" similar to what happens when on an airplane, except it fluctuated every 3 or 4 seconds, continuously for 15 minutes or so. I still don't understand why this would occur, so if anyone here has a good grasp of ear physiology relating to heavy cardio load, I would love an explanation.
9:00 AM - I took half of a Modafinil tablet (Indian brand, I have taken before with no ill effects, but never in combination with Phenibut).
11:00 AM - Took half of the remaining half tablet, having now taken 3/4 of said tablet.
11:00 AM - Dosed 300mg of Phenibut (a rather small dose)
I planned on taking 200mg more Phenibut 2 hours prior to a training session at my local gym.
3:00 PM - Took said 200mg
5:00 PM - Downed half a cup of coffee, drove to gym feeling fine, began workout session.
Now, normally I do a warm up run before my workout session starts, but this time I didn't arrive early enough, so I dove into the workout. I don't think this would have been a big factor, however, as my warmup runs often involve a similar or even greater level of exertion than my training sessions.
5:30 PM - Began experiencing symptoms of [over-exertion? dehydration?] Felt tingling in extremities. Heart rate not rapid but fast and heavy. Felt dizzy and unable to exert myself. Felt at brink of exhaustion.
5:35 PM - After a short rest, I continue working out. Once again, feel at brink of exhaustion. Nausea is creeping up. I sit down.
5:40 PM - Suddenly, middle ear pressure begins to fluctuate wildly. Whenever I speak or breathe, my eardrums pressurize and depressurize. There is no homeostatis. I develop a moderate headache. 5 or 6 on a scale of 10. I began to feel very concerned and worried. My trainer suggests we stop. Our session ends and I sit on a bench, trying to retain my composure.
5:43 PM - I am on the verge of calling 911. The pressure changes in my ears continue, and it is very disorienting. I am afraid I am having a stroke. I start to worry about the effects of Modafinil and caffeine. Are they vasoconstrictive in combo? I wonder to myself.
5:47 PM - I drive home. Ear pressure still unstable. Everything looks very bright. I am not going to panic; however, I pull over, open my car door and sit, leaning out, pulling up a browser on my smartphone. I type in "symptoms of stroke" in the search bar. After calming down slightly, I continue home.
5:50 PM - Call girlfriend. She calms me down. She asked how much water I had had in the day. I had had 2 full glasses the entire day prior to workout. I think this may have been the culprit.
The rest of the night I felt drained and worn out. After doing some thinking, I came to the conclusion that what happened was a simple case of OVEREXERTION, made worse by lack of hydration, and use of Modafinil, which has stimulant properties.
I just want to reiterate that I don't really think it was the substances that caused this event, but the combination of substances, heavy exertion, and dehydration.
If you made it this far, thanks for reading.