Suggest Treatment For Tingling In Left Arm

After 2 years of daily use,I have increased my adderall dosage from 20mg once per day to 20mg twice per day, morning, then early evening. since the increase, I have noticed mild but sharp shooting pains/tingling from my left deltoid down my left arm to the palm of my left hand. What could this indicate? am I at risk for long term damage? what should I screen for? (past what my insurance would cover if necessary) What has research said about adderall now that it has been in use for 2 decades. I am a 31 year old african american/mexican male otherwise in great health...please advise