Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Stop taking this medicine and call your doctor at once if you have:
blurred vision, tunnel vision, eye pain, or seeing halos around lights;
a light-headed feeling, like you might pass out;
fast, slow, or uneven heart rate;
signs of liver or pancreas problems--loss of appetite, upper stomach pain (that may spread to your back), nausea or vomiting, fast heart rate, dark urine, jaundice (yellowing of the skin or eyes);
high potassium level--nausea, weakness, tingly feeling, feeling weak or tired, slow heartbeats, loss of movement;
low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling;
kidney problems--little or no urination, swelling in your feet or ankles, feeling tired or short of breath;
lupus-like symptoms--muscle or joint pain, flu symptoms, chest pain, and a rash or patchy skin color that worsens in sunlight; or
other signs of an electrolyte imbalance--thirst, dry mouth, stomach pain, drowsiness, weakness, fast heart rate, muscle pain or weakness, feeling restless or light-headed.
Common side effects may include:
stomach pain, nausea, diarrhea, constipation;
dizziness, headache;
blurred vision; or
dry mouth.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Hydrochlorothiazide/triamterene side effects (more detail)
