Hydrochlorothiazide belongs to the thiazide class of diuretics, acting on the kidneys to reduce sodium (Na) reabsorption in the distal convoluted tubule. This increases the osmolarity in the lumen, causing less water to be reabsorbed by the collecting ducts. This leads to increased urinary output.
If overdose is suspected, seek immediate medical attention. Symptoms of overdose may include unconsciousness, nausea/vomiting, weakness, slow or shallow breathing, dizziness, confusion, unusually slow heartbeat, seizures, drowsiness, or fainting.