Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using this medication and call your doctor at once if you have any of these serious side effects:
fast, pounding, or uneven heartbeat;
confusion, hallucinations, unusual thoughts or behavior;
severe dizziness, anxiety, restless feeling, or nervousness;
increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure);
confusion, hallucinations, unusual thoughts or behavior;
slow, shallow breathing;
urinating less than usual or not at all;
easy bruising or bleeding, unusual weakness, fever, chills, body aches, flu symptoms; or
nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Less serious side effects may include:
blurred vision;
dry mouth;
nausea, stomach pain, constipation;
mild loss of appetite, stomach upset;
warmth, tingling, or redness under your skin;
sleep problems (insomnia);
restless or excitability (especially in children);
skin rash or itching;
dizziness, drowsiness;
problems with memory or concentration; or
ringing in your ears.
