Renal function impairment with hypertension

Renal function impairment In hypertensive patients with normal kidneys who are treated with hydralazine, there is evidence of increased renal blood flow and a maintenance of glomerular filtration rate. Renal function may improve where control values were below normal prior to administration. Use with caution in patients with advanced renal damage. 

Renal function impairment Some hypertensive patients with renal disease, particularly those with severe renal artery stenosis, have developed increases in BUN and serum creatinine after reduction of BP. 

Renal function impairment The active metabolites of methyidopa accumulate in uremia. Use with caution in renal failure. Prolonged hypotension has been reported. Hypertension has recurred occasionally after dialysis in patients given methyidopa because the drug is removed by this procedure. 

In two kidney-one clip hypertensive rabbits without significant impairment of renal function, treatment with indomethacin for 10 days is without effect on blood pressure although it reduces plasma renin activity . In contrast, in two kidney-one clip hypertensive rabbits having high plasma renin activity and depressed renal haemodynamics, chronic treatment with indomethacin aggravates both the hypertension and the renal function impairment . In the latter study, plasma renin activity, which initially was reduced by indomethacin, returned on subsequent days to pretreatment levels pari passu with the increase in blood pressure and the deterioration of renal function . Chronic indomethacin treatment also exacerbates the hypertension, and depresses renal excretory function, in rats with two kidney-one clip hypertension . However, short-term treatment with indomethacin lowers blood pressure, associated with reduction of plasma renin activity, in rats with two clip—one kidney hypertension . Indomethacin also produces correlated decrements of blood pressure and plasma renin activity in rats made hypertensive by complete ligation of the aorta between the renal arteries . In contrast, shortterm treatment with indomethacin or meclofenamate is without effect on blood pressure in dogs with two kidney—one clip hypertension . 

Agents acting in the proximal tubule are seldom used to treat hypertension. Treatment is usually initiated with a thiazide-type diuretic. Chlorthalidone and indapamide are structurally different from thiazides but are functionally related. If renal function is severely impaired (i.e., serum creatinine above 2.5 mg/dl), a loop diuretic is needed. A potassium-sparing agent may be given with the diuretic to reduce the likelihood of hypokalemia. 

In the first 2 weeks post-MI, caution is advised and careful dose titration is especially important, particularly in patients with markedly impaired ventricular function. Intraoperative and postoperative tachycardia and hypertension Do not use esmolol as the treatment for hypertension in patients in whom the increased blood pressure is primarily caused by the vasoconstriction associated with hypothermia. Renal/Hepatic function impairment Use with caution. 

Sustained hypertension There is a dose-dependent increase in the incidence of sustained hypertension for venlafaxine from 3% for doses less than 100 mg/day up to 13% for doses greater than 300 mg/day. It is recommended that patients receiving venlafaxine have regular monitoring of blood pressure. For patients who experience a sustained increase in food pressure, consider dose reduction or discontinuation. Renal/Hepatic function impairment In patients with renal impairment (GFR, 10 to 70 mL/min) or cirrhosis of the liver, a lower dose may be necessary. 

Hypertension alone or in combination with other CV-antihypertensive-ARBs PO Initially, 16 mg once a day in those who are not volume depleted. Can be given once or twice a day with total daily doses of 8-32 mg. Give lower dosage in those treated with diuretics or with severely impaired renal function. 

Hypertension in patients with impaired renal function PO 3 75 mg once a day in patients with creatinine clearance of 40 ml/min. Maximum May titrate up to 15 mg/day. 

Shock states associated with impaired renal function. Pulmonary hypertension. 

It is usually recommended that ACE inhibitors be continued peri-operatively in common with other antihypertensives. There is some evidence that postoperative haemodynamic stability is improved and renal function protected. Pretreatment with ACE inhibitors may reduce tachyphylaxis to sodium nitroprusside and help to prevent rebound hypertension. On the other hand, there is evidence that ACE inhibitors may predispose to hypotension during anaesthesia and that they reduce cerebral blood flow during any period of systemic hypotension. Furthermore, the response to and recovery from hypotensive episodes due to blood loss or circulatory depletion may be impaired. At present, the advice concerning these drugs would be to continue therapy up to and including the day of operation. Another rare side-effect of ACE inhibitors is angioneurotic oedema, which has occasionally been seen complicating intubation. 

This patient has a massively raised ALT, indicating considerable hepato-cyte damage. All functions of the liver are likely to be affected, including reduced secretory and excretory function, demonstrated in this case by a raised bilirubin reduced synthetic function, shown by the raised INR (albumin is imaffected at this time due to its long half life) reduced metabolic function, indicated by accumulation of ammonia and other toxins leading to encephalopathy. Blood flow through the liver is likely to be unaffected, as there is no cirrhosis/portal hypertension. As with all other functions of the liver, this patient s ability to metabolise drugs is likely to be severely affected. Renal function is also impaired secondary to paracetamol toxicity. 

Chau NP, Weiss YA, Safar ME, Lavene DE, Georges DR, Milliez P. Pindolol availability in hypertensive patients with normal and impaired renal function. Clin Pharmacol Ther 1977 22 505-10. 

ACE inhibitors and AT -receptor blockers are most useful in hypertension when the raised blood pressure results from excess renin production (e.g. renovascular hypertension), or where concurrent use of another drug (diuretic or calcium blocker) renders the blood pressure renin-dependent. The fall in blood pressure can be rapid, especially with short-acting ACE inhibitors, and low initial doses of these should be used in patients at risk those with impaired renal function, or suspected cerebrovascular disease. These patients may be advised to omit any concurrent diuretic treatment for a few days before the first dose. The antihypertensive effect increases progressively over weeks with continued adminis-... 

In a randomized comparison of celecoxib and diclofenac plus omeprazole, renal adverse events, including hypertension, peripheral edema, and renal insufficiency, were common and similar in the two groups (105). They occurred in the 24% of the patients who took celecoxib and in 31% of those who took diclofenac plus omeprazole. Among patients with renal impairment at baseline, 51% of those who took celecoxib and 41% of those who took diclofenac plus omeprazole had renal adverse events. Careful monitoring of renal function in patients taking COX-2 inhibitors or traditional NSAIDs is mandatory, especially in high-risk subjects (for example those with pre-existing renal disease, diabetes, or heart failure). 

Several reports have linked renal dysfunction with nifedipine. In a study of hypertensive diabetics with renal insufficiency, nifedipine increased proteinuria and worsened renal function (SEDA-16, 196). Others have reported mild reversible renal impairment in patients with chronic renal insufficiency taking nifedipine for angina or hypertension a biopsy in one of the patients, who had heavy proteinuria, showed focal and segmental glomerulosclerosis (30). Immune-complex nephritis was reported in a patient taking nifedipine, but the proteinuria persisted (and indeed worsened) on changing to verapamil (31). 

Furosemide natriuresis and kaliuresis can be reduced by short-term treatment with piroxicam in hypertensive patients with impaired renal function (SEDA-16,113). 

Among 25 infants born after 27 pregnancies in tacrohmus-treated liver transplant patients there was an unexpectedly low incidence of hypertension, pre-eclampsia, and ahograft function abnormalities, whereas preterm delivery, low birth weight, and transient mUd renal impairment with hjrperkalemia in neonates occurred at a similar rate (99). 

Agents used to treat acute gout attacks as well as to prevent recurrent attacks should be used with caution in patients with hypertension and renal impairment. Doses may need to be adjusted in patients with decreased renal function. Probenecid is usually recommended for patients who are under 60 years of age, who have normal renal function, are diagnosed as an underexcreter, and have no history of kidney stones. Probenecid causes a marked increase of uric acid in the urine, and decreased renal elimination places the patient at risk for stone formation. Allopurinol is a good choice for patients with uric acid stones or renal insufficiency, as well as for those who are known to be overproducers of uric acid. 

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