For adults who are treating high blood pressure with hydrochlorothiazide, dosing generally starts at 25 mg once a day. The dosage for helping with fluid retention varies between 25 mg and 100 mg per day. For children and infants, hydrochlorothiazide dosing is based on the child's weight and is generally 0.5 mg to 1 mg per pound per day.
The dose of hydrochlorothiazide (HCTZ) that your healthcare provider recommends will vary depending on a number of factors, including:
- Other medical conditions you may have
- Other medications you may be currently taking
- How you respond to hydrochlorothiazide.
As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
The recommended starting dose of hydrochlorothiazide for treating high blood pressure is hydrochlorothiazide 25 mg once daily. Based on the initial blood pressure response and/or side effects of hydrochlorothiazide, the dosage may be increased up to 50 mg per day. With each change in dosage, it may take several weeks to see the full effects of hydrochlorothiazide on lowering blood pressure.
The recommended dose of hydrochlorothiazide for fluid retention (edema) can vary between 25 mg and 100 mg daily (taken as a single dose or divided and taken more frequently). Some people will only need to take hydrochlorothiazide when they need it (when they are experiencing water retention), while others may need to take hydrochlorothiazide on a daily basis.
Usually, the dose of hydrochlorothiazide for infants and children is 0.5 mg to 1 mg per pound per day. This can be given as one daily dose or split up into two doses per day. The dose should not exceed 37.5 mg total per day for infants up to two years old or 100 mg per day for children two to twelve years old. In some infants less than six months old, higher doses (up to 1.5 mg per pound per day) may be necessary.