Frusenex – Pharmacology:
Frusenex, by inhibiting the reabsorption of sodium and chloride in the ascending limb of the loop of Henle, increases the urinary excretion of sodium, chloride and water. Frusenex also increases the excretion of potassium, hydrogen, calcium, magnesium, ammonium and phosphate and, by inhibiting carbonic anhydrase, bicarbonate.
Frusenex for patients
Frusenex is a diuretic (water pill) used to treat fluid retention and hypertension. Do not take this drug if you are allergic to sulfa medicine. Inform your doctor if you are pregnant or breastfeeding. Tell your doctor if you have diabetes mellitus. Blood glucose levels can be increased in patients with diabetes mellitus. Take this drug at the beginning of the day. Frusenex can be taken with or without food. Take with food or milk if stomach upset occurs. Tell your doctor if you develop weakness, cramps, or nausea. Dizziness or vertigo can occur with therapy; avoid sudden changes in posture. Frusenex can cause increased sensitivity to sunlight. Use sunscreens and wear protective clothing until you determine the degree of sensitivity.
Frusenex may increase the ototoxic potential of aminoglycoside antibiotics, especially in the presence of impaired renal function. Except in life-threatening situations, avoid this combination.
Frusenex should not be used concomitantly with ethacrylic acid due to the possibility of ototoxicity. Patients receiving high doses of salicylates concomitantly with furosemide, as in rheumatic disease, may experience salicylate toxicity at lower doses due to competitive renal excretory sites.
Frusenex has a tendency to antagonize the relaxing effect of tubocurarine in skeletal muscle and can enhance the action of succinylcholine.
Lithium should generally not be given with diuretics as they reduce the renal clearance of lithium and add a high risk of lithium toxicity.
Frusenex can add or enhance the therapeutic effect of other antihypertensive drugs. Potentiation occurs with ganglionic or peripheral adrenergic blocking drugs.
Frusenex can reduce the arterial response to norepinephrine. However, noradrenaline can still be used effectively.
Concomitant administration of sucralfate and furosemide tablets may reduce the natriuretic and antihypertensive effects of furosemide. Patients receiving both drugs should be carefully observed to determine if the desired diuretic and / or antihypertensive effect of furosemide is achieved. The intake of furosemide and sucralfate must be separated by at least two hours.
Tablets, injection and oral solution
A six-subject study showed that the combination of furosemide and acetylsalicylic acid temporarily reduced creatinine clearance in patients with chronic renal failure. There are case reports of patients who developed increased BUN, serum creatinine and serum potassium levels and weight gain when furosemide was used in combination with NSAIDs.
Literature reports indicate that concomitant administration of indomethacin may reduce the natriuretic and antihypertensive effects of furosemide in some patients by inhibiting prostaglandin synthesis. Indomethacin can also affect plasma renin levels, aldosterone excretion and evaluation of the renin profile. Patients receiving both indomethacin and furosemide should be carefully observed to determine if the desired diuretic and / or antihypertensive effect of furosemide is achieved.
Frusenex is contraindicated in patients with anuria and in patients with a history of hypersensitivity to furosemide.