What side effects can this medication cause?  

Meperidine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• lightheadedness
• dizziness
• weakness
• headache
• extreme calm
• mood changes
• confusion
• agitation
• upset stomach
• vomiting
• stomach pain or cramps
• constipation
• dry mouth
• flushing
• sweating
• changes in vision

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them or those listed in the IMPORTANT WARNING section, call your doctor immediately:

• slow or difficult breathing
• shaking hands that you cannot control
• muscle twitches or stiffening
• seizures
• hallucination (seeing things or hearing voices that do not exist)
• slow, fast, or pounding heartbeat
• difficulty urinating
• fainting
• rash
• hives

Meperidine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online at http://www.fda.gov/MedWatch/report.htm or by phone 1-800-332-1088.