Nephrogenic hypertension

Antagonism may be defined as the situation in which the toxicity of two or more compounds present or administered together or sequentially is less than would be expected in terms of their toxicities when administered separately. Antagonism may be due to chemical or physical characteristics of the pollutants, or it may be due to the biological actions of the pollutants involved. For example, the highly toxic metal cadmium (Cd) is known to induce anemia and nephrogenic hypertension as well as teratogenesis in animals. Zinc (Zn) and... 

The answer is a. (Katzung, pp 255-256.) Thiazide diuretics can be used in the treatment of nephrogenic diabetes insipidus. Its other uses include the treatment of hypertension, CHF, and nephrolithiasis due to idiopathic hypercalcuria. 

See Table 15-5. The major indications for thiazide diuretics are (1) hypertension, (2) heart failure, (3) nephrolithiasis due to idiopathic hypercalciuria, and (4) nephrogenic diabetes insipidus. Use of the thiazides in each of these conditions is described in Clinical Pharmacology of Diuretic Agents. 

Hydrochlorothiazide Inhibition of the Na/CI transporter in the distal convoluted tubule Modest increase in NaCI excretion some wasting hypokalemic metabolic alkalosis t decreased urine Ca Hypertension, mild heart failure, nephrolithiasis, nephrogenic diabetes insipidus Oral duration 8-12 h Toxicity Hypokalemic metabolic alkalosis, hyperuricemia, hyperglycemia, hyponatremia... 

The pressor amines have been implicated also in the nephrogenic theories of hypertension. In 1910 Ewins and Laidlaw (73) commented that the formation of tyramine from tyrosine in the intestine has quite recently been regarded as playing a part in certain pathological states in which a high blood pressure is the most prominent symptom. Contemporarily, Bain (12) reported that tyramine was excreted in the urine of hypertensive patients but to a less extent than in patients having normal blood pressure, the implication being that the elevation in blood pressure was due to the retention of tyramine. The urohypertensin of Abelous and Bardier (1) contained isoamylamine. 

Q9 Thiazides are considered first-line drugs in the treatment of hypertension in older people. They are also used in mild heart failure and to inhibit kidney stone formation in hypercalciuria, in addition to their use in treatment of nephrogenic diabetes insipidus. 

Thiazide diuretics are used in the management of edema, the management of hypertension, the treatment of nephrogenic diabetes insipidus, and the prophylaxis of renal calculus formation. 

Patients with nephrogenic diabetes insipidus often have polydipsia and polyuria (see Chap. 49). They adapt well to their urinary-concentrating defect and these concerns are usually minimal. Acute tubular necrosis is frequent in the setting of acute hthium toxicity. Urinalysis may show moderate proteinuria, a few red and white blood cells, and granular casts. Renal function usuahy returns to baseline values after hthium concentrations are reduced to the therapeutic range. Nephrotoxicity may develop insidiously and be recognized by rising BUN or creatinine concentrations or the onset of hypertension. The urinalysis may show mild proteinuria and a few red and white blood cells. 

The role that cyclic nucleotides may play in the etiology and/or maintenance of a number of disease states is becoming clearer. In asthma, the ability of patients with this disease to excrete increased amounts of cyclic AMP in urine in response to epinephrine is greatly diminished, possibly due to a disease-related decrease in the sensitivity of adenylyl cyclase (AC) to the catecholamine. This lack of AC sensitivity however could be reversed by corticoid therapy in accord with the long established permissive effects of these hormones on cyclic AMP synthesis. In nephrogenic diabetes insipidus, diminished urinary production of cyclic AMP in response to ADH was also reported. Other conditions that may involve deficient cyclic AMP production include hypertension , psoriasis and stroke . On the other hand, cyclic AMP production appears... 

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