Metolazone with furosemide

In order to correct potassium losses and the consequent diuretic-induced hypokalemia, spironolactone or triamterene can be successfully combined with the thiazide, metolazone, chlorthalidone, furosemide or ethacrynic acid. 

The risks and benefits of distal tubular diuretics have been assessed in preterm infants under 3 weeks of age with or developing chronic lung disease (36). Acute and chronic administration of distal diuretics improved pulmonary mechanics adverse effects were not reported. However, additional studies are needed to assess whether thiazide administration improves mortality, duration of oxygen dependency, ventilator dependency, length of hospital stay, and long-term outcome in patients exposed to corticosteroids and bronchodilators, and whether adding spironolactone to thiazides or adding metolazone to furosemide has any beneficial effect. 

The answer is c. (Hardman, pp 704-706J Triamterene produces retention of the K ion by inhibiting in the collecting duct the reabsorption of Na, which is accompanied by the excretion of K ions. The loop diuretics furosemide and bumetanide cause as a possible adverse action the development of hypokalemia. In addition, thiazides (e g, hydrochlorothiazide) and the thiazide-related agents (e.g., metolazone) can cause the loss of K ions with the consequences of hypokalemia. Triamterene can be given with a loop diuretic or thiazide to prevent or correct the condition of hypokalemia. 

The most important side effects of the thiazide diuretics, chlorthalidone, furosemide, ethacrynic acid and metolazone are potassium losses with resultant hypokalemia, and hyperuricemia. Hyperuricemia may result in acute attacks of gouty arthritis in individuals with a gouty diathesis. 

A 78-year-old man became short of breath. He had been taking rosiglitazone 8 mg/day for 6 months. He had renal insufficiency, atrial fibrillation, hypertension, and congestive heart failure, with pitting edema and bilateral pleural effusions. He was refractory to intravenous furosemide and metolazone. Withdrawal of rosiglitazone and administration of bumetanide gave a net fluid output of 9.5 litres and the edema resolved. 

Thiazide diuretics are ineffective once the GFR becomes less than 25 mL/min, and loop diuretics are often used at high doses (e.g. furosemide 500 mg to 1 g daily) to gain an effect. Metolazone is effective when combined with a loop diuretic. Potassium-sparing diuretics such as amiloride are not recommended. Spironolactone is not generally used, but is beneficial in low dose for the treatment of heart failure even in patients on dialysis. Beta-blockers and calcium channel blockers are generally well tolerated. Any ankle swelling with calcium channel blockers must not be confused with fluid overload. 

Acute renal insufficiency with severe hyponatremia has been attributed to vigorous diuretic treatment (metolazone, furosemide, spironolactone) with an ACE inhibitor (27). Because ACE inhibition impairs renal protection against reduced perfusion, the combination of an ACE inhibitor with high-dose furosemide causes a reduction in glomerular filtration rate linearly related to the change in blood pressure. 

Clinically important, potentially hazardous interactions with alprazolam, amiodarone, amphotericin B, arbutamine, bendroflumethiazide, benzthiazide, bisacodyl, bumetanide, carbimazole, chlorothiazide, chlorthalidone, cholestyramine, clarithromycin, conivaptan, cyclosporine, cyclothiazide, dan-shen, demeclocycline, devil s claw, dexmedetomidine, doxycycline, erythromycin, esomeprazole, ethacrynic acid, flunisolide, furosemide, ginseng, glycopyrrolate, glycopyrronium, hawthorn (fruit, leaf, flower extract), horsetail, hydrochlorothiazide, hydroflumethiazide, indapamide, licorice, lopinavir, mepenzolate, methyclothiazide, metolazone, minocycline, mistletoe, oxprenolol, oxytetracycline, paroxetine, phenylbutazone, polythiazide, propafenone, propantheline, quinethazone, quinidine, rabeprazole, rifampin, roxithromycin, sarsaparilla, senna, Siberian ginseng, squill, St John s wort, telithromycin, teriparatide, tetracycline, thiazide diuretics, tolvaptan, trichlormethiazide, verapamil... 

Acute, fatal, renal failure developed in 2 patients with cardiac failure within 4 weeks of being treated with enalapril and furosemide, and in 2 similar patients renal impairment developed over a longer period. Reversible renal failure developed in a patient with congestive heart failure when captopril and metolazone were given. ... 

Isolated cases of nephrotoxicity have been described when patients taking ciclosporin were given either amiloride with hydrochlorothiazide, metolazone, or mannitol. Furosemide can possibly protect the kidney against ciclosporin damage. The concurrent use of ciclosporin with thiazides, but not loop diuretics, may increase serum magnesium levels. The concurrent use of ciclosporin with potassium-sparing diuretics may cause hyperkalaemia. 

A 39-year-old man taking ciclosporin, whose second kidney transplant functioned subnormally, and who required treatment for hypertension with atenolol and minoxidil, developed ankle oedema, which was resistant to furosemide, despite doses of up to 750 mg daily. When metolazone 2.5 mg daily was added for 2 weeks his serum creatinine levels more than doubled, from 193 to 449 micromol/L. When metolazone was stopped the creatinine levels fell again. Ciclosporin serum levels were unchanged and neither graft rejection nor hypovolaemia occurred. ... 

Acute renal failure was reported in a 35-year-old woman with systemic lupus erythematosus taking four capsules daily of a cat s claw product (species unspecified) for an unspecified length of time. The woman was also taking other medications including prednisone, atenolol, metolazone, furosemide, and nifedipine. Biochemical parameters for renal function were reported to return to normal after cessation of the cat s claw product (Hilepo et al. 1997). 

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