Fusid PLUS 20 mg Tab

Overview

Fusid Plus Tablet (Furosemide 20 mg + Spironolactone 50 mg) combines a loop diuretic with an aldosterone antagonist. Furosemide produces rapid, potent diuresis by blocking the Na⁺-K⁺-2Cl⁻ transporter in the loop of Henle, while spironolactone competitively inhibits aldosterone at the distal nephron, conserving potassium and countering the hypokalaemia typically caused by furosemide. This synergistic combination is indicated for essential hypertension, congestive heart failure, hepatic cirrhosis with ascites, oedema, and primary or secondary hyperaldosteronism.

Dosage and Administration

The usual adult dose is 1–4 tablets daily (equivalent to 20–80 mg furosemide + 50–200 mg spironolactone), taken in the morning or in divided doses. The dose is adjusted according to the severity of fluid retention and blood pressure response. Tablets should be swallowed whole with water, with or without food. Avoid taking late in the day to minimise nocturia.

Interaction

ACE inhibitors, ARBs, and potassium supplements may cause dangerous hyperkalaemia when combined with the spironolactone component — monitor serum potassium closely. Digoxin levels may be elevated, increasing toxicity risk. NSAIDs reduce the diuretic and antihypertensive effect. Aminoglycosides used concurrently increase ototoxicity risk. Lithium clearance is reduced, raising serum levels and toxicity risk.

Contraindications

Contraindicated in anuria, acute renal insufficiency, creatinine clearance below 30 ml/min, hyperkalaemia, Addison's disease, and hypersensitivity to furosemide, sulphonamides, spironolactone, or any component. Avoid concurrent use with other potassium-sparing diuretics or potassium supplements without close monitoring.

Side Effects

Electrolyte disturbances including hyperkalaemia (from spironolactone) and hyponatraemia are important risks. Other effects include dehydration, postural hypotension, muscle cramps, nausea, and gastric upset. Spironolactone may cause gynaecomastia, menstrual irregularities, and sexual dysfunction with long-term use. Furosemide may cause hyperuricaemia and transient glucose intolerance.

Pregnancy and Lactation

Both furosemide and spironolactone cross the placenta. Spironolactone has shown anti-androgenic effects in animal studies. This combination should be used during pregnancy only when clearly necessary and under close medical supervision. Both agents are present in breast milk; breastfeeding is not recommended during treatment.

Precautions and Warnings

Monitor serum electrolytes (particularly potassium and sodium), renal function, and blood pressure regularly. The potassium-sparing effect of spironolactone partially offsets furosemide-induced potassium loss, but the balance must be monitored — hyperkalaemia is as dangerous as hypokalaemia. Use with caution in elderly patients and those with diabetes. Avoid in patients with severe hepatic impairment.

Storage Conditions

Protect from light. Store in a cool, dry place. Keep out of reach of children.

Frequently Asked Questions

Q: Why are furosemide and spironolactone combined in Fusid Plus?
A: Furosemide is a powerful diuretic but causes significant potassium loss (hypokalaemia), which can be dangerous — particularly for patients on digoxin. Spironolactone conserves potassium at the distal nephron. Combining the two creates balanced, effective diuresis with a reduced risk of dangerous electrolyte imbalance.

Q: Can Fusid Plus 20+50 mg and Fusid Plus 40+50 mg be used interchangeably?
A: No. The two strengths have different amounts of furosemide (20 mg vs 40 mg) and are prescribed based on the degree of fluid retention and individual patient response. Always take the strength prescribed by your physician, and do not adjust the dose without medical advice.