What are the side affects of taking prochlorperazine if it's not your prescribed tablet?

If you took a single tablet by mistake then you might be alright. iIf you took a couple and didn't really need it then these are the known side effects you may experience.

Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Prochlorperazine:

Blurred vision; chills; constipation; dizziness; drowsiness; dry mouth; jitteriness; nasal congestion; sleeplessness.

Seek medical attention right away if any of these SEVERE side effects occur when using Prochlorperazine:

Expand this post...

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); agitation; altered mental abilities, including lack of response to your surroundings; changes in breasts; changes in menstrual period; changes in vision; difficulty swallowing; drooling; excessive sweating; fever; inability to move eyes; increased body heat; involuntary movements of tongue, face, mouth, or jaw (eg, protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements); irregular or fast heartbeat; mask-like face; muscle spasms of face, neck, or back; muscle stiffness; prolonged or painful erection; restlessness; rigid muscles; shuffling walk; sore throat; tension in legs; tremors; twitching or twisting movements; unusual eye movements; weakness of arms or legs; yellowing of the skin or eyes.

http://www.drugs.com/sfx/prochlorperazine-side-effects.html