SIDE EFFECTS: You may experience dizziness, lightheadedness, blurred vision, or tiredness as your body adjusts to the medication. You may also experience diarrhea, dry mouth, nausea, vomiting, or cough. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Tell your doctor immediately if any of these unlikely but serious side effects occur: unusual thirst, weakness, confusion, fainting, fast heartbeat, decreased sexual ability. Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: unusual change in the amount of urine (after the first several days of starting this drug), signs of infection (e.g., fever, chills, persistent sore throat), seizures, chest pain, yellowing eyes or skin, stomach/abdominal pain, dark urine, unusual fatigue. An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include: rash, itching, swelling (especially of the face, lips, tongue, or throat), severe dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.

PRECAUTIONS: This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: urinary problems (inability to make urine or anuria). Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease, heart problems, severe loss of body fluids (dehydration through excessive sweating, vomiting, or diarrhea), mineral/electrolyte problems (e.g., imbalance of sodium, potassium, magnesium, calcium), diabetes, gout, lupus, high levels of fats in the blood (high cholesterol or triglycerides), asthma, any allergies (especially to sulfa drugs or ACE inhibitors such as captopril, lisinopril). This drug may make you dizzy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages. To minimize dizziness and lightheadedness, get up slowly when rising from a seated or lying position. Before having surgery, tell your doctor or dentist that you are taking this medication. Hydrochlorothiazide may make you more sensitive to the sun. Avoid prolonged sun exposure, tanning booths or sunlamps. Use a sunscreen and wear protective clothing when outdoors. Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug, especially the dizziness effect. This medication should be used only when clearly needed during the first three months of pregnancy. It is not recommended for use during the last six months of the pregnancy due to the risk for fetal harm. Discuss the risks and benefits with your doctor. See also the Warning section. Hydrochlorothiazide passes into breast milk. Breast-feeding is not recommended due to the potential harm to the nursing infant. Consult your doctor before breast-feeding.