Calcium diuretics

CALCIUM DIURETICS-THIAZIDES Risk of hypercalcaemia with high-dose calcium 1 renal excretion of calcium by thiazides Monitor calcium levels closely... 

Clinically important, potentially hazardous interactions with aluminium, antacids, anticoagulants, bismuth, calcium, diuretics, iron preparations, magnesium, oral contraceptives, oral retinoids, quinapril... 

Calcium chloride solutions, typically employed at 2—5% concentration, are used as antispasmodics, diuretics (qv), and in the treatment of tetany. Concentrated solutions of calcium chloride cause erythema, exfoUation, ulceration, and scarring of the skin (39). Injections into the tissue may cause necrosis. If given orally calcium chloride can cause irrita tion to the gastrointestinal tract unless accompanied by a demulcent. There is no pubHshed information on mutagenicity or carcinogenicity caused by calcium ions or calcium chloride. Calcium chloride has been given a toxicity or hazard level 3 (40). Materials in this classification typically have LD q below 400 mg/kg or an LC q below 100 ppm. 

ACE inhibitors can be administered with diuretics (qv), cardiac glycosides, -adrenoceptor blockers, and calcium channel blockers. Clinical trials indicate they are generally free from serious side effects. The effectiveness of enalapril, another ACE inhibitor, in preventing patient mortaUty in severe (Class IV) heart failure was investigated. In combination with conventional dmgs such as vasodilators and diuretics, a 40% reduction in mortaUty was observed after six months of treatment using 2.5—40 mg/d of enalapril (141). However, patients complain of cough, and occasionally rash and taste disturbances can occur. 

Patients having high plasma renin activity (PRA) (>8 ng/(mLh)) respond best to an ACE inhibitor or a -adrenoceptor blocker those having low PRA (<1 ng/(mLh)) usually elderly and black, respond best to a calcium channel blocker or a diuretic (184). -Adrenoceptor blockers should not be used in patients who have diabetes, asthma, bradycardia, or peripheral vascular diseases. The thiazide-type diuretics (qv) should be used with caution in patients having diabetes. Likewise, -adrenoceptor blockers should not be combined with verapamil or diltiazem because these dmgs slow the atrioventricular nodal conduction in the heart. Calcium channel blockers are preferred in patients having coronary insufficiency diseases because of the cardioprotective effects of these dmgs. 

Calcium channel blockers normalize the blood pressure in about 80% of hypertensive patients older than 60 years of age, 50% of those between 40 and 60 years of age, and only 20% of patients under 40 years of age. Thus calcium channel blockers are best for patients who are elderly and have low PRA and mosdy ineffective in patients who have high PRA. This responsiveness profile is very similar to that of the diuretics. 

Calcium channel blockers cause more pronounced lowering of blood pressure in hypertensive patients than in normotensive individuals. Generally, all calcium channel blockers cause an immediate increase in PRA during acute treatment in patients having hypertension but PRA is normalized during chronic treatment despite the sustained decrease in blood pressure. These agents also do not generally produce sodium and water retention, unlike the conventional vasodilators. This is because they produce diuretic effects by direct actions on the kidney. 

Intake of a large amount of sodium chloride negates the antihypertensive effects of diuretics. Other mechanisms, such as direct vasodilating action, decreased responsiveness to vasopressor agents, stimulation of prostacyclin [35121 -78-9] production, and reduction in the intracellular calcium... 

The sales of oral diuretics are declining, and are forecast to continue their decline in constant dollars during the 1990s (119,120). Several possible explanations can be offered for these trends. The patents of market leaders are expiring, lea ding to the introduction of generic brands at ca 40% below the cost of the branded market leaders physicians are switching to newer treatments for hypertension, eg, calcium channel blockers and... 

In the treatment of hypertension, ACE inhibitors are as effective as diuretics, (3-adrenoceptor antagonists, or calcium channel blockers in lowering blood pressure. However, increased survival rates have only been demonstrated for diuretics and (3-adrenoceptor antagonists. ACE inhibitors are approved for monotherapy as well as for combinational regimes. ACE inhibitors are the dtugs of choice for the treatment of hypertension with renal diseases, particularly diabetic nephropathy, because they prevent the progression of renal failure and improve proteinuria more efficiently than the other diugs. 

ACE inhibitors - AT antagonists - Alpha blockers - Beta blockers Isolated syslolic hypertension (older patienls) - Diuretics preferred (generally Thiazides) - Long-acting dihydropyridine calcium channel blocker... 

The first inhibitor of NHE, amiloride, was identified in 1982. This drug is a potassium-sparing diuretic that also inhibits the sodium-calcium exchanger and the conductive Na+ channel. Not all the NHE isoforms are inhibited equally by amiloride NHE1 and 2 are responsive, NHE5 is partially responsive and NHE3, 4 and 7 are resistant. Other weak and non-specific inhibitors are clonidine and cimetidine. 

Calcium is contraindicated in patients with hypercalcemia or ventricular fibrillation and in patients taking digitalis. Calcium is used cautiously in patients with cardiac disease. Hypercalcemia may occur when calcium is administered with the thiazide diuretics. When calcium is administered with atenolol there is a decrease in Hie effect of atenolol, possibly resulting in decreased beta blockade. There is an increased risk of digitalis toxicity when digitalis preparations are administered with calcium. The clinical effect of verapamil may be decreased when the drug is administered with calcium. Concurrent ingestion of spinach or cereal may decrease file absorption of calcium supplements. 

To combat this syndrome the physician may prescribe IV sodium chloride and a potent diuretic, such as furosemide. When used together these two drugs markedly increase calcium renal clearance and reduce hypercalcemia... 

Thiazide diuretics, calcium-containing antacids, vitamin D, and lithium... 

Patients with asymptomatic left ventricular systolic dysfunction and hypertension should be treated with P-blockers and ACE inhibitors. Those with heart failure secondary to left ventricular dysfunction and hypertension should be treated with drugs proven to also reduce the morbidity and mortality of heart failure, including P-blockers, ACE inhibitors, ARBs, aldosterone antagonists, and diuretics for symptom control as well as antihypertensive effect. In African-Americans with heart failure and left ventricular systolic dysfunction, combination therapy with nitrates and hydralazine not only affords a morbidity and mortality benefit, but may also be useful as antihypertensive therapy if needed.66 The dihydropyridine calcium channel blockers amlodipine or felodipine may also be used in patients with heart failure and left ventricular systolic dysfunction for uncontrolled blood pressure, although they have no effect on heart failure morbidity and mortality in these patients.49 For patients with heart failure and preserved ejection fraction, antihypertensive therapies that should be considered include P-blockers, ACE inhibitors, ARBs, calcium channel blockers (including nondihydropyridine agents), diuretics, and others as needed to control blood pressure.2,49... 

Patients with diabetes and hypertension should initially be treated with either P-blockers, ACE inhibitors, ARBs, diuretics, or calcium channel blockers. There is a general consensus that therapy focused on RAAS inhibition by ACE inhibitors or ARBs may be optimal if the patient has additional cardiovascular risk factors such as left ventricular hypertrophy or chronic kidney disease.2,3,59,67... 

Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs. diuretic The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA 2002 288(23) =2981-2997. 

Medications (analgesics, anticholinergerics, calcium channel blockers, clonidine, diuretics, phenothiazines, tricyclic antidepressants, iron supplements, calcium- and aluminum-containing antacids)... 

Therapeutic measures that have been used to decrease the incidence of contrast-induced nephropathy include extracellular volume expansion, minimization of the amount of contrast administered, and treatment with oral acetylcysteine. Theophylline, fenoldopam, loop diuretics, mannitol, dopamine, and calcium antagonists have no effect or may worsen ARF. 

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