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 immediately if any of the following side effects occur:
Less common
Abdominal or stomach pain
anxiety
blurred vision
changes in patterns and rhythms of speech
chest pain or tightness
chills
confusion
dizziness
fast, slow, irregular, pounding, or racing heartbeat or pulse
headache
muscle cramps and stiffness
neck, throat, or jaw pain
nightmares
shivering
sweating
swelling of the fingers, hands, feet, or lower legs
tightness in the chest
trouble breathing
Rare
Blindness
chest pain or discomfort
chest tightness or heaviness
flushing or redness of the skin, especially on the face and neck
increased blinking or spasms of the eyelid
itching, pain, redness, or swelling
lightheadedness, dizziness, or fainting
nerve pain
severe numbness, especially on one side of the face or body
severe or continuing stomach pain
trouble speaking or swallowing
twitching
unusual bleeding or bruising
vomiting of blood or material that looks like coffee grounds
weakness of the arms and legs
Incidence not known
Agitation
back, leg, or stomach pains
bleeding gums
changes in vision
muscle twitching
pinpoint red spots on the skin
poor coordination
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
restlessness
skin rash, hives, or itching
unexplained bleeding or bruising
unusually warm skin
weakness in the arm or leg on one side of the body, sudden and severe
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:
Less common
Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
change in color vision
change in hearing
difficulty with concentrating
drowsiness
heartburn
increased sensitivity of the eyes to sunlight
joint pain
muscle aching or cramping
muscle stiffness or tightness
swollen joints
trouble sleeping
Rare
Aggressiveness
belching
change in taste
feeling halos around lights
increased sensitivity to pain
loss of appetite
numbness, pain, tingling, or weakness
stomach discomfort or upset
tingling in the hands and feet
tunnel vision
weakness
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.
 Sumatriptan side effects (more detail)
