I'm still waiting on my gastro dr. appt., and had to make another trip to the ER this past Tuesday-- thought I was having a heart attack, again, but thankfully, again, I wasn't. So the ER doc said it was most likely GERD and gave me a prescription for Prilosec 40 mg. I took one this morning and I thought my head was going to fall off! My lips started tingling and I became dizzy and stayed "off" most all day long--pretty scary! Thankfully it has now worn off. Has any one ever had weird side effects from Prilosec? I am going back to the 20 mg twice a day on the advice of my family dr. Thanks!