Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Less common
Chills
cough
diarrhea
fever
general feeling of discomfort or illness
headache
joint pain
loss of appetite
muscle aches and pains
nausea
runny nose
shivering
sore throat
sweating
trouble sleeping
unusual tiredness or weakness
vomiting
Rare
Abdominal or stomach pain
blistering, itching, peeling, or redness of skin
bloody or cloudy urine
clay-colored stools
convulsions
dark urine
difficult, burning, or painful urination
dizziness
frequent urge to urinate
muscle spasm or jerking of all extremities
rash
sudden loss of consciousness
unpleasant breath odor
vomiting of blood
yellow eyes or skin
Symptoms of overdose
Get emergency help immediately if any of the following symptoms of overdose occur:
Blurred vision
confusion
convulsions
disorientation
dizziness
drowsiness (severe)
faintness or lightheadedness when getting up from a lying or sitting position
fast, pounding, or irregular heartbeat or pulse
hyperexcitability
loss of consciousness
palpitations
sweating
unusual tiredness or weakness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Weight gain
Less common or rare
Bloody nose
drowsiness
dryness of mouth
excitation
increased appetite
irritability
nervousness
swelling of eyelids
unexplained nosebleeds
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
 Ketotifen ophthalmic side effects (more detail)
