Blood pressure Hypertension Hypotension

Tretinoin (Vesanoid] Acute promyelocytic leukemia Cardiac arrhythmias edema blood pressure abnormalities (hypotension, hypertension] phlebitis respiratory tract problems muscle pain paresthesias CNS toxicity (depression, anxiety, confusion] skin rash Gl distress (abdominal distension nausea, vomiting]... 

The solution with the higher concentration of solute is said to be hypertonic , while the solution with the lower concentration is hypotonic . You have probably come across these terms, hyper- and hypo-, in other areas, such as the slang term for being over-excitable - a person is described as being hyper They actually originate from old Greek words now used in medical terms hyper- means excessive and hypo- means under. So hypertension is high blood pressure and hypotension is low... 

In patients taking midodrine for orthostatic hypotension, the nurse checks the blood pressure with the patient supine and sitting before therapy is begun. This is important because midodrine is contraindicated in patients with supine hypertension. 

Essential hypertension, whose prevalence is increased nearly two-fold in the diabetic population, may be another source of free-radical activity. The vascular lesions of hypertension can be produced by free-radical reactions (Selwign, 1983). In the recent Kuopio Ischaemic Heart Risk Factor Study in Finnish men, a marked elevation of blood pressure was associated with low levels of both plasma ascorbate and serum selenium (Salonen etal., 1988). A few studies report a hypotensive effect of supplementary ascorbate in patients with hypertension, but the actual changes in both systolic and diastolic pressure after ascorbate were not statistically significant in comparison with placebo (Trout, 1991). 

The treatment of elderly patients with hypertension, as well as those with isolated systolic hypertension, should follow the same approach as with other populations with the exception that lower starting doses may be warranted to avoid symptoms and with special attention paid to postural hypotension. This should include a careful assessment of orthostatic symptoms, measurement of blood pressure in the upright position, and caution to avoid volume depletion and rapid titration of antihypertensive therapy.2 In individuals with isolated systolic hypertension, the optimal level of diastolic pressure is not known, and although treated patients who achieve diastolic pressures less than 60 to 70 mm Hg had poorer outcomes in a landmark trial, their cardiovascular event rate was still lower than those receiving placebo.69... 

Apart from possible clinical differences between the P-block-ers approved for HF, selection of a p-blocker may also be affected by pharmacologic differences. Carvedilol exhibits a more pronounced blood pressure lowering effect and thus causes more frequent dizziness and hypotension as a consequence of its ar receptor blocking activity. Therefore, in patients predisposed to symptomatic hypotension, such as those with advanced LV dysfunction (LVEF less than 20%) who normally exhibit low systolic blood pressures, metoprolol succinate may be the most desirable first-line P-blocker. In patients with uncontrolled hypertension, carvedilol may provide additional antihypertensive efficacy. 

Sodium nitroprusside (SNP), which is also known as Nipruss or Nipride to medical practitioners, was the first iron nitrosyl complex, prepared as far back as 1850 by Playfair [40]. The hypotensive property of SNP was first demonstrated by Johnson [41] in 1929. It was shown that application of a moderate dose of SNP reduces the blood pressure of a severely hypertensive patient without any side effect [42]. Since that time considerable research has been carried out to understand the mode of action of nitroprusside and its metabolic fate. SNP is now regarded as a potent vasodilator that causes muscle relaxation by releasing NO which activates the cytosolic isozyme of guanylyl cyclase [43-46]. 

Hypertension is a well known contributor to a number of diseases, but hypotension can be equally dangerous as tissues rely upon pressure to maintain a constant delivery of nutrients via the micro-circulation of fluid around individual cells. As pressure and volume are interdependent, blood pressure is controlled by either changing the internal diameter of the vessels (vasoconstriction or vasodilation) or by increasing the fluid volume contained within the vasculature. 

Cardiovascular system S-HTj, 5-HT2 and S-HTg receptors may be involved in the complex action of serotonin on blood pressure 5-HT2 agonists appear to be hypertensive agents whereas the antagonists are hypotensives... 

Terazosin is an alpha-adrenoreceptor blocker that causes vasodilation and is used in the management of hypertension and benign prostatic hypertrophy. Beta-blockers and alpha-blockers can interact to induce hypotension since both act to reduce the blood pressure. Patients already on beta-blockers and who are started on alpha-blockers such as terazosin should be advised to take the terazosin dose at night to reduce the implications (falls) of first-dose hypotension. 

The molecular mechanism of diuretics acting as antihypertensive agents is not completely clear however, use of diuretics causes a significant increase in the amount of water and electrolytes excreted in urine, which leads to a reduction in the volume of extracellular fluid and plasma. This in turn leads to a reduction of cardiac output, which is the main parameter responsible for a drop in arterial blood pressure and venous blood return. Cardiac output is gradually restored, but the hypotensive effect remains, possibly because of the reduced peripheral resistance of vessels. It is also possible that diuretics somehow lower vascular activity of noradrenaline and other factors of pressure in the organism. Methods of synthesizing thiazide diuretics used for hypertension are described in the preceding chapter. Chapter 21. 

Sodium nitroprusside is a powerful, instantaneous-acting intravenous drug used to lower blood pressure in hypertensive crises. The hypotensive effect is caused by peripheral vasodilation resulting from a direct effect on both arterial and venous vessels. 

Hypotension Hypotension (postural) occurs regularly in about 50% of patients while they are supine, manifested by dizziness, light-headedness, vertigo, or faintness. Tolerance occurs unpredictably but may be present after several days. Hypotension with supine systolic pressure above 75 mm Hg need not be treated unless symptomatic. If supine systolic pressure falls below 75 mm Hg, infuse dopamine or norepinephrine to increase blood pressure use dilute solution and monitor blood pressure closely because pressor effects are enhanced by bretylium. Perform volume expansion with blood or plasma and correct dehydration where appropriate. Transient hypertension and increased frequency of arrhythmias Transient hypertension and increased frequency of arrhythmias may occur due to initial release of norepinephrine from adrenergic postganglionic nerve terminals. 

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