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:

dry mouth or thirst
nausea
vomiting
feeling weak, drowsy, restless, or light-headed
fast or uneven heartbeat
muscle pain or weakness
urinating less than usual or not at all
red or purple spots on your skin
numbness or tingly feeling
a red, blistering, or peeling skin rash
stomach pain, low fever, or loss of appetite
dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes)

Continue using chlorothiazide and talk with your doctor if you have any of these less serious side effects:

dizziness
headache
muscle spasm
blurred vision

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
 

FDA Information

Why is this medication prescribed?

Other uses for this medicine

Dosage and using this medicine

What special precautions should I follow?

What should I do if I forget a dose?

What storage conditions are needed for this medicine?

In case of an emergency/overdose