Drug Prescribing for Patients with Chronic Kidney Disease in General Practice: a Cross-Sectional Study

There is growing evidence that aldosterone plays an important role in the development of endorgan-damage e.g. vascular and cardiac fibrosis, remodeling and endothelial dysfunction. Aldosterone-antagonism has become a novel therapeutic principle beyond its sodium retention properties in the treatment of cardiovascular diseases. In patients with severe left ventricular dysfunction spironolactone could reduce death and hospitalisation. A new selective aldosterone antagonist, eplerenone, was effective in patients with left ventricular dysfunction after myocardial infarction added to optimal medical therapy.

Hypertension is considered refractory when the use of three pharmacologically different antihypertensives (included a diuretic, a sympathetic blocker and a vasodilator) given at maximum dose fails to lower the blood pressure to below 140/90 mmHg. In the event of isolated systolic hypertension, the value should be reduced to below 140 mmHg. A truly refractory form may be assumed in some 2-5% of all hypertensives, and must be differentiated from a pseudo form in which such factors as counter-regulatory mechanisms, inadequate use of general measures, inadequate antihypertensive therapy, interactions with other drugs, or secondary hypertension may play a role. Refractory patients in whom the underlying cause cannot be identified should be referred to an appropriate specialist. Diuretic treatment should first be optimized and antihypertensive doses maximized (with consideration being given to side effects). Further substances such as minoxidil in combination with a beta-blocker and a diuretic may be used.

Die Behandlung der arteriellen Hypertonie ist weltweit weiterhin unzureichend etabliert. Nur 6 bis 27% der behandelten Hypertoniker sind auf Werte unter 140/90 mmHg eingestellt. Obwohl zahlreiche, gut wirksame medikamentöse Therapieprinzipien verfügbar sind, ist die weitere Entwicklung neuer gut verträglicher blutdrucksenkender Pharmaka möglichst mit zusätzlichen organprotektiven Effekten notwendig, um bessere Behandlungserfolge zu erzielen. Die Regulation des Blutdrucks erfolgt multifaktoriell und entsprechend vielfältig sind pharmakologische Interventionsmöglichkeiten. Eine wesentliche Bedeutung bei der Blutdruckregulation kommt dem Renin-Angiotensin-Aldosteron-System (RAAS) zu, das über lokale und systemische Wirkungen den Blutdruck beeinflusst. Die zugrundeliegenden Mechanismen sind gut untersucht und weitgehend bekannt. Neben dem Renin-Angiotensin-Aldosteron-System ist in neueren Untersuchungen insbesondere die Bedeutung des Natriuretischen-Peptid-Systems (NPS) für die Kreislaufregulation herausgearbeitet worden. Die natriuretischen Peptide (NP) modulieren die Blutdruckregulation über renale, zentrale und lokal vaskuläre Mechanismen.

Elevated diastolic as well as elevated systolic blood pressure substantially contributes to the increase of cardiovascular risk. Conclusive results have proven that lowering diastolic and/or systolic blood pressure can reduce cardiovascular risk. There is evidence that not only the absolute values for diastolic and systolic blood pressure alone but also the pulse pressure as an additional indicator of cardiovascular risk have to be considered. The prevalence of isolated systolic hypertension increases with age. Remodeling of the arterial wall with increase of collagen and decrease of elastic fibers are leading to an impaired compliance. Decreased compliance and acceleration of the pulse wave velocity can elevate systolic and lower diastolic blood pressure. Cardiac stress and pulse pressure in consequence will rise. In elderly patients there is a strong correlation between cardiovascular mortality and morbidity and systolic blood pressure. Antihypertensive therapy is able to lower cardiovascular morbidity and mortality in elderly patients with isolated systolic hypertension with a predominant risk reduction for stroke.

Although inadequate lowering of elevated blood pressure is not unusual in the doctor's office, both physician and patient accept such a situation. One reason for this therapeutic failure may be either a true or an apparent therapy-resistance, with the latter being far the more common of the two, and often associated with a multiplicity of causes. Since cerebral complications in particular correlate directly with the level of blood pressure, a search for the underlying cause is always worthwhile for the patient.

We report on a 67 year old man in whom the chest x-ray revealed marked interstitial opacities in both lungs. The diagnosis of Rheumatoid Arthritis (RA) was established by the presence of five criteria of the American College of Rheumatology for diagnosing RA. High resolution computertomography of the chest confirmed the abnormalities seen in the conventional chest x-ray. A biopsy, taken by open lung surgery, showed the typical pattern of pulmonary involvement in RA and confirmed the association of RA and interstitial lung fibrosis. The histologic examination pointed out lymphocytic infiltration of the bronchies, thickened alveolar walls with lymphoplasmarcellular infiltration and an increase in fibrous connective tissue. A congestive heart failure with severe arrhythmias and an obstructive sleep apnea syndrome (OSAS) were diagnosed in addition. The rhythm disturbances were attributed to the participation of the myocardium in RA and/or by the OSAS. By the treatment with prednisolone, methotrexate, mexiletine and continuous positive airway pressure (CPAP) the rhythm disturbances were alleviated and the patient's condition improved.