Bendroflumethiazide

Bendroflumethiazide is a thiazide diuretic used in the management of hypertension and edema. It works by inhibiting sodium reabsorption in the distal convoluted tubules in the kidneys, promoting the excretion of sodium and water while conserving potassium. This mechanism helps in reducing blood pressure and the removal of excess fluid from the body.

Mechanism of Action

Bendroflumethiazide inhibits the sodium/chloride transporter in the distal convoluted tubule, leading to an increase in the excretion of sodium, chloride, and water. This diuretic effect decreases plasma volume, promoting the reduction of blood pressure and the resolution of edema. Additionally, it has a mild effect on reducing the excretion of potassium, which can help in preventing hypokalemia, a common side effect of diuretics.

Indications

Bendroflumethiazide is primarily indicated for the treatment of:

• Hypertension - as a monotherapy or in combination with other antihypertensive agents.
• Edema - associated with heart failure, chronic liver disease, and renal dysfunction.

Pharmacokinetics

After oral administration, bendroflumethiazide is absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 2 to 4 hours. It is extensively bound to plasma proteins and is metabolized in the liver. The elimination half-life is approximately 3 to 6 hours, and it is excreted mainly by the kidneys.

Adverse Effects

Common adverse effects of bendroflumethiazide include:

• Hypokalemia - low potassium levels in the blood.
• Hyponatremia - low sodium levels in the blood.
• Hyperuricemia - elevated levels of uric acid, which can exacerbate or precipitate gout attacks.
• Hyperglycemia - elevated blood glucose levels.
• Dizziness and light-headedness, particularly at the start of therapy.

Less common but more serious adverse effects may include:

• Severe electrolyte imbalances.
• Allergic reactions, including rash and photosensitivity.
• Pancreatitis and cholecystitis.

Contraindications

Bendroflumethiazide is contraindicated in patients with:

• Severe renal impairment.
• Anuria - absence of urine production.
• Known hypersensitivity to sulfonamide-derived drugs, as thiazides are chemically related to sulfonamides.

Drug Interactions

Bendroflumethiazide can interact with several other medications, including:

• Lithium - may increase lithium toxicity.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) - may reduce the antihypertensive effect of bendroflumethiazide.
• Digitalis - increased risk of digitalis toxicity due to hypokalemia.
• Antidiabetic drugs - may require adjustment of antidiabetic medication doses due to hyperglycemia.

Dosage and Administration

The dosage of bendroflumethiazide varies depending on the condition being treated and the patient's response to therapy. It is typically taken once daily, preferably in the morning to avoid nocturia. Dose adjustments may be necessary based on the patient's renal function and electrolyte levels.

Conclusion

Bendroflumethiazide is a valuable medication in the management of hypertension and edema. However, its use requires careful monitoring of electrolytes and renal function to avoid adverse effects. Patients should be educated about the potential side effects and the importance of regular follow-up appointments to ensure safe and effective treatment.