_ abdominal pain
_ aggravation, nervousness, hostility, sadness
_ drug dependence
_ dizziness
_ headache
_ tics
_ insomnia and prolonged sleepiness
_ loss of appetite
_ increased coughing, sinusitis, upper respiratory tract infection
_ vomiting
_ allergic reaction
_ increased blood pressure
_ psychosis (abnormal thinking or hallucinations).
i hope this helps
yvonne

an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);
an irregular or fast heartbeat;
chest pains or very high blood pressure (blurred vision, severe headache, flushing);
unusual behavior or confusion; or
liver damage (yellowing of the skin or eyes, nausea, abdominal pain or discomfort, unusual bleeding or bruising, severe fatigue).

Other, less serious side effects may be more likely to occur.
Continue to take methylphenidate and talk to your doctor if you experience

insomnia (difficulty sleeping);
nervousness;
drowsiness;
dizziness;
headache;
blurred vision;
tics (repetitive movements);
abdominal pain, nausea, or vomiting;
decreased appetite or weight loss; or
slower weight gain and/or growth.

These are just symptoms for people that take the NORMAL dosage. Otherwise:

Symptoms of a methylphenidate overdose include agitation, tremors (shaking), muscle twitches, seizures, confusion, hallucinations, sweating, flushing, headache, fast or irregular heartbeat, large pupils, and dryness of the mouth and eyes.

To you and Carolea, Concerta and other methylphenidate containing medications can cause drug dependence. So you should try to control this overuse because if you overdose too much, you can get really sick and possibly die. Of course you’d have to swallow the container too to die.

Infrequent side effects:
Angina Severe
Sinus Irritation and Congestion Severe
Inflammation of Skin caused by an Allergy Severe
Hives Severe
Joint Pain Severe
Fever Severe
Involuntary Quivering Severe
Voluntary Movement Difficulty Severe
Rash Severe
Chest Pain Severe
Reaction due to an Allergy Severe
Decreased Blood Platelets Severe
Throat Irritation Less Severe
Acute Infection of the Nose, Throat or Sinus Less Severe
Drowsiness Less Severe
Dizzy Less Severe
Head Pain Less Severe
Cough Less Severe
Feel Like Throwing Up Less Severe
Stomach Cramps Less Severe

Rare side effects:
Tourette’s Severe
Blurred Vision Severe
Problems with Eyesight Severe
Cramps Severe
Seizures Severe
Fit Severe
Weight Loss Severe
Anemia Severe
Decreased White Blood Cells Severe
Mental Disorder Resulting from Poisonous Agents Severe
Mood Changes Severe
Inflammation of the Nose Less Severe
Pain During Periods Less Severe
Throwing Up Less Severe
Diarrhea Less Severe