From the Guidelines
Bendroflumethiazide can cause several side effects, including increased urination, dizziness, headache, and electrolyte imbalances, and patients taking this medication should have regular blood tests to monitor electrolytes and kidney function, stay hydrated, and report any concerning symptoms to their healthcare provider. The most common side effects of bendroflumethiazide include:
- Increased urination
- Dizziness
- Headache
- Electrolyte imbalances such as low potassium (hypokalemia), low sodium (hyponatremia), and low magnesium levels Some patients may experience:
- Increased blood sugar levels
- Elevated uric acid (which can trigger gout attacks)
- Increased cholesterol levels Less common but still notable side effects include:
- Skin rashes
- Photosensitivity (increased sensitivity to sunlight)
- Digestive disturbances like nausea or diarrhea
- Erectile dysfunction in men Rarely, bendroflumethiazide can cause more serious reactions such as:
- Blood disorders
- Pancreatitis
- Severe skin reactions According to the most recent and highest quality study, 1, the usual dose range for bendroflumethiazide is 2.5-5 mg/day, and patients should be monitored for hyponatremia and hypokalemia, uric acid and calcium levels. Additionally, the study suggests that combination therapy of potassium-sparing diuretic with a thiazide can be considered in patients with hypokalemia on thiazide monotherapy, but should be avoided in patients with significant CKD (eg, GFR <45 mL/min).
From the FDA Drug Label
Dilutional hyponatremia may occur in edematous patients in hot weather; Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy Latent diabetes mellitus may become manifest during thiazide administration. Thiazides may decrease serum PBI levels without signs of thyroid disturbance. Calcium excretion is decreased by thiazides Pathological changes in the parathyroid gland with hypercalcemia and hypophosphatemia have been observed in a few patients on prolonged thiazide therapy. Thiazides have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.
The side effects of bendroflumethiazide include:
- Dilutional hyponatremia
- Hyperuricemia or gout
- Latent diabetes mellitus
- Decreased serum PBI levels
- Decreased calcium excretion
- Hypercalcemia and hypophosphatemia due to pathological changes in the parathyroid gland
- Hypomagnesemia due to increased urinary excretion of magnesium 2
From the Research
Bendroflumethiazide Side Effects
- The side effects of bendroflumethiazide were reported to be slight in a study published in the British journal of urology 3.
- One patient developed symptomatic hyperuricaemia and another patient had sustained hypercalcaemia in the same study 3.
- In a study comparing bendroflumethiazide/potassium chloride with hydrochlorothiazide/amiloride, both treatments were found to be effective and well tolerated in controlling patients with mild to moderate hypertension 4.
- A meta-analysis of dose-response relationships for hydrochlorothiazide, chlorthalidone, and bendroflumethiazide found that the potency series for diastolic BP, serum potassium, and urate were similar to those seen for systolic BP, with bendroflumethiazide being the most potent 5.
- A comparative trial of hydrochlorothiazide and bendroflumethiazide in low doses found that few subjective side effects were reported, with no significant difference between the two treatments in terms of hypotensive effect, effect on potassium and uric acid in serum, fasting blood glucose, or any other variable studied 6.