Indapamide: a unique diuretic?

Stripping voltammetric determination of indapamide in serum at castor oil-based carbon paste electrodes

The diuretic drug indapamide has been characterized voltammetrically at carbon paste electrodes by means of cyclic and differential pulse voltammetry. An adsorptive stripping method at carbon paste electrode modified with castor oil for trace determination of indapamide was described. A study of the variation of the peak current with solution variables such as pH, ionic strength, concentration of indapamide, possible interference, and instrumental variables such as scan rate, pulse amplitude, preconcentration time, accumulation potential, paste composition has resulted in the optimization of the oxidation signal for analytical purposes. By anodic stripping differential pulse voltammetry, the calibration plot was linear in the range 5 x 10(-8) x 10(-7) M with a detection limit of 5 x 10(-9) M at carbon paste electrode modified with castor oil in pH 4.0. The preconcentration medium-exchange approach was utilized for selective determination of indapamide in spiked serum. A detection limit of 15 ng ml(-1) was obtained for dilute serum sample after 3 min accumulation and medium-exchange procedure.

Central nervous system considerations in the use of beta-blockers, angiotensin-converting enzyme inhibitors, and thiazide diuretics in managing essential hypertension

The most common mild side effects occurring with use of beta-blockers, thiazide diuretics, and angiotensin-converting enzyme inhibitors for blood pressure control are central nervous system symptoms, specifically lethargy, sedation, and fatigue. These symptoms affect 5% to 10% of patients taking these drugs. The mechanism by which beta-blockers may induce central nervous system effects is uncertain. Relative lipophilicity as a factor affecting penetrance of the blood-brain barrier has not proved to be a reliable predictor of whether the drug will cause such disturbances. Comparisons of atenolol (hydrophilic) and metoprolol (lipophilic) have shown no differences between these drugs with respect to side effects of the central nervous system. The incidence of central nervous system effects with angiotensin-converting enzyme inhibitors is similar to that for most beta-blockers. The precise role of the angiotensin-converting enzyme in the central nervous system is not well defined. Most thiazide diuretics are not associated with major complications of the central nervous system, although electrolyte imbalance may occasionally lead to complaints of neurologic symptoms. Because the incidence of central nervous system effects with these three classes of drugs is so low, concern for the side effects of the central nervous system is not a prime consideration in the choice of an initial antihypertensive agent.