Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0730345 (microalbuminuria)
 4,018 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angiotensin II receptor blockers (ARBs) represent a new class of effective and well tolerated orally active antihypertensive agents. Recent clinical trials have shown the added benefits of ARBs in hypertensive patients (reduction in left ventricular hypertrophy, improvement in diastolic function, decrease in ventricular arrhythmias, reduction in microalbuminuria, and improvement in renal function), and cardioprotective effect in patients with heart failure. Several large long-term studies are in progress to assess the beneficial effects of ARBs on cardiac hypertrophy, renal function, and cardiovascular and cerebrovascular morbidity and mortality in hypertensive patients with or without diabetes mellitus, and the value of these drugs in patients with heart disease and diabetic nephropathy. The ARBs specifically block the interaction of angiotensin II at the AT1 receptor, thereby relaxing smooth muscle, increasing salt and water excretion, reducing plasma volume, and decreasing cellular hypertrophy. These agents exert their blood pressure-lowering effect mainly by reducing peripheral vascular resistance usually without a rise in heart rate. Most of the commercially available ARBs control blood pressure for 24 h after once daily dosing. Sustained efficacy of blood pressure control, without any evidence of tachyphylaxis, has been demonstrated after long-term administration (3 years) of some of the ARBs. The efficacy of ARBs is similar to that of thiazide diuretics, beta-blockers, angiotensin-converting enzyme inhibitors or calcium channel blockers in patients with similar degree of hypertension. Higher daily doses, dietary salt restriction, and concomitant diuretic or ACE inhibitor administration amplify the antihypertensive effect of ARBs. The ARBs have a low incidence of adverse effects (headache, upper respiratory infection, back pain, muscle cramps, fatigue and dizziness), even in the elderly patients. After the approval of losartan, five other ARBs (candesartan cilexetil, eprosartan, irbesartan, telmisartan, and valsartan) and three combinations with hydrochlorothiazide (irbesartan, losartan and valsartan) have been approved as antihypertensive agents, and some 28 compounds are in various stages of development. The ARBs are non-peptide compounds with varied structures; some (candesartan, losartan, irbesartan, and valsartan) have a common tetrazolo-biphenyl structure. Except for irbesartan, all active ARBs have a carboxylic acid group. Candesartan cilexetil is a prodrug, while losartan has a metabolite (EXP3174) which is more active than the parent drug. No other metabolites of ARBs contribute significantly to the antihypertensive effect. The variation in the molecular structure of the ARBs results in differences in the binding affinity to the receptor and pharmacokinetic profiles. The differences observed in lipid solubility, absorption/distribution, plasma protein binding, bioavailability, biotransformation, plasma half-life, and systemic elimination influence the time of onset, duration of action, and efficacy of the ARBs. On the basis of the daily mg dose, the antihypertensive potency of the ARBs follows the sequence: candesartan cilexetil > telmisartan approximately = losartan > irbesartan approximately = valsartan > eprosartan. After oral administration, the ARBs are rapidly absorbed (time for peak plasma levels = 0.5-4 h) but they have a wide range of bioavailability (from a low of 13% for eprosartan to a high of 60-80% for irbesartan); food does not influence the bioavailability, except for valsartan (a reduction of 40-50%) and eprosartan (increase). A limited dose-peak plasma levels/areas under the plasma level-time curve proportionality is observed for some of the ARBs. Most of these drugs have high plasma protein binding (95-100%); irbesartan has the lowest binding among the group (90%). The steady-state volumes of distribution vary from a low of 9 L (candesartan) to a high of 500 L (telmisartan). (ABSTRACT TRUNCATE
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PMID:Clinical pharmacokinetics of angiotensin II (AT1) receptor blockers in hypertension. 1085 85

To evaluate efficacy and tolerability of telmisartan, an angiotensim II receptor blocker, in reducing microalbuminuria in adult Indian hypertensive patients with type 2 diabetes mellitus, a prospective, open-label, non-comparative, assessor-blind, multicentric, pilot study was conducted in 60 eligible hypertensive patients with type 2 diabetes mellitus and microalbuminuria after obtaining their informed consent. The study was approved by the respective institutional review boards. Each patient received telmisartan 40 mg initially once daily for first 4 weeks which was titrated upwards to 80 mg once daily for the next 8 weeks. Blood pressure was assessed at the end of every 2 weeks and urinary albumin excretion and creatinine clearance were measured at baseline and after 12 weeks of therapy. Safety outcome measures included monitoring of physical examination, laboratory parameters and monitoring treatment-emergent adverse events. Fifty-five patients completed the study while 5 cases were lost to follow-up. The mean age of the patients was 48.27 years. Of the total patients 63.6% were males and 46.4% were females. At baseline the mean urinary albumin excretion rate was 131.81 +/- 38.82 mg/minute. A statistically significant (p < 0.05) reduction (32.96%) in urinary albumin excretion rate occurred after 12 weeks of therapy (118.36 +/- 37.22). The mean pre-study systolic blood pressure was 165.05 +/- 15.24 mmHg which was significantly (p < 0.05) reduced to 123.72 +/- 5.88 mmHg at the end of 12 weeks. At baseline the mean diastolic blood pressure was 103.55 +/- 9.84 mmHg which was significantly (p < 0.05) reduced to 84.71 +/- 8.54 mmHg. The JNC-VII goal of blood pressure below 130/80 was achieved in 34 (61.8%)of the 55 patients at the end of 12 weeks. Both fasting and postprandial blood sugar levels were well-controlled at the end of the study. Telmisartan was well tolerated with only 9.09% of the patients reported mild and transient adverse events like fatigue, dizziness, nausea and diarrhoea. No abnormalities were detected in the laboratory parameters. The results of this pilot study indicate that telmisartan is effective, safe and well tolerated while reducing microalbuminuria in adult Indian hypertensive patients with type 2 diabetes mellitus.
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PMID:A pilot study for evaluation of the efficacy and safety of telmisartan in reducing microalbuminuria in hypertensive patients with type 2 diabetes mellitus. 1617 97