Hi all, I've recently upped my dosage of Prozac this week. Went from 20mg to 40mg. Can this cause anxiety to spike because last 5 days I've been terrible. Like convinced I'm dying heart attack due any moment now, despite having bloods and ecg done Thursday it feels so real to me. I know when I first took the tablets they caused me bad anxiety so I'm hoping that it is that again. You're sincerely, a very scared, upset, lonely 25yo male.