Serum digoxin levels after concomitant ticarcillin and clavulanic acid administration.

Recently it has been recognized that steady-state serum digoxin concentrations may increase or fall to ineffective levels when the glycoside is administered together with several antibiotics. Our study was designed to assess if serum digoxin levels may be modified by the concomitant use of a ticarcillin and clavulanic acid. The study was carried out in 15 hospitalized patients suffering from exacerbation of their chronic bronchitis without liver disease and renal failure. Serum digoxin levels were not significantly modified by the concomitant use of a ticarcillin and clavulanic acid, although peak digoxin serum concentrations were slightly lower. However, the average time to achieve the maximum concentration and area under the curve over 24 h did not change.

Theophylline in the inhibition of angiotensin-converting enzyme inhibitor-induced cough.

Preliminary reports suggest that some pharmacologic agents may be effective in ameliorating angiotensin-converting enzyme (ACE) inhibitor-induced cough and, perhaps, allowing continuing use of ACE inhibitors in patients for whom this class of medication is important. We examined the effect of a once-a-day theophylline formulation on ACE inhibitor-induced cough and on the sensitivity of the cough reflex to capsaicin in 10 hypertensive patients who had developed cough during treatment with an ACE inhibitor. Theophylline did not induce bronchodilation but induced complete remission of clinical symptoms in 8 and attenuated the capsaicin-induced cough number in 7 subjects when compared with placebo. Theophylline may thus be effective in preventing ACE inhibitor-induced cough.

Transmitral flow changes during dipyridamole-induced ischemia. A Doppler-echocardiographic study.

Myocardial ischemia results in altered left ventricular (LV) diastolic compliance, reflected by an abnormal mitral inflow pattern on Doppler echocardiography. To investigate the relationship of Doppler echocardiography and regional myocardial systolic function during dipyridamole infusion, we evaluated transmitral flow changes detected by pulsed Doppler technique during a high-dose dipyridamole echocardiography test (DET, two-dimensional echo monitoring with dipyridamole infusion, up to 0.84 mg/kg over 10 min). The DET response produced two groups: group 1 (34 patients) with negative DET, and group 2 (35 patients) with positive DET, defined as the development of a newly onset LV regional asynergy. The E/A values overlapped at baseline (1.07 +/- .32 vs .92 +/- .22; p = NS) but differed at peak changes (.92 +/- .26 vs. 75 +/- .25; p less than .01). Heart rate changes could not account for the observed Doppler changes, since the values of R-R interval were similar in the groups, both basally (.927 +/- .226 vs .867 +/- .143 s; p = NS) and at peak dipyridamole (.754 +/- .100 vs. 681 +/- .112; p = NS). Transient myocardial ischemia induced by dipyridamole administration is accompanied by changes in transmitral flow, which consist of an increase in the relative atrial contribution to LV filling, possibly owing to an acute impairment in LV relaxation.

Dipyridamole-echocardiography test in essential hypertensives with chest pain and angiographically normal coronary arteries.

Microvascular angina--chest pain syndrome in the presence of angiographically normal epicardial coronary arteries and reduced flow reserve--has been described in patients with essential hypertension (EH) and linked to the development of left ventricular hypertrophy (LVH). We performed a dipyridamole-echocardiography test (DET: 2D-echo and 12 lead ECG monitoring with dipyridamole infusion, up to 0.84 mg/kg over ten minutes) in 28 essential hypertensives meeting the following inclusion criteria: (1) history of chest pain; (2) angiographically normal coronary arteries; (3) normal resting regional and global left ventricular function. A group of 12 (age- and sex-matched) normotensives with the same inclusion criteria, as well as with negative exercise stress test, was also evaluated. During DET, none of the essential hypertensives or the control group developed a regional dyssynergy of contraction. Fifteen essential hypertensives and two in the control group had a diagnostic (greater than 0.1 mV from baseline) ST segment depression on ECG tracing (54 v 17%, P less than .01); 16 essential hypertensives and two in the control group had chest pain (57 v 17%, P less than .01). None of the control group and nine of the essential hypertensives had echocardiographically assessed LVH. In the essential hypertensive group ventricular hypertrophy was present in seven of 20 patients with and in two of eight patients without dipyridamole induced chest pain and/or ST segment depression (35% v 25%, P = NS). In conclusion, essential hypertensive patients with chest pain and angiographically normal coronary arteries frequently show echocardiographically silent angina and/or ST segment depression during DET.(ABSTRACT TRUNCATED AT 250 WORDS)