Hemodynamic and pharmacokinetic study of tertatolol in patients with alcoholic cirrhosis and portal hypertension

Tertatolol, a recently developed beta 1-beta 2-blocker has two advantages: it does not induce withdrawal syndrome after abrupt cessation, and it preserves renal function. It has been suggested that the kinetics of tertatolol in patients with hepatic dysfunction are altered. Therefore, the hemodynamic effects and pharmacokinetics following the acute administration of tertatolol were studied in cirrhotic patients with portal hypertension. Systemic, splanchnic and renal hemodynamics were evaluated before and 30 min after the simultaneous administration of 2.5 mg tertatolol p.o. and 1.25 mg deuterated tertatolol i.v. in 10 cirrhotic patients with esophageal varices. The pharmacokinetics of tertatolol were evaluated over a 4-day period. Tertatolol significantly decreased heart rate (-22 +/- 10%), cardiac output (-26 +/- 8%), and hepatic blood flow (-27 +/- 23%). The hepatic venous pressure gradient decreased from 15.7 +/- 5.0 to 12.9 +/- 4.0 mmHg (-17 +/- 13%, P < 0.01). Three out of 10 patients were non-responders to tertatolol. Renal blood flow (-9 +/- 28%) and intrinsic hepatic clearance of indocyanin green (-9 +/- 25%) were not significantly modified. The duration of effective beta-blockade was far less than 12 h. Tertatolol was rapidly absorbed with a Cmax of 70 +/- 51 micrograms/l at a peak time of 0.75 +/- 0.26 h. In comparison with healthy volunteers referred to in literature sources, plasma clearance was reduced to 49 +/- 28 ml/min, bioavailability was increased to 72 +/- 20%, and the volume of distribution was increased to 50 +/- 34 l, probably due, in part, to a weaker protein binding -85%--effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in growth phenotype and radiosensitivity after fractionated irradiation of breast carcinoma cells from a single patient

PURPOSE

To investigate growth regulation and radiosensitivity in surviving clonogens after fractionated irradiation.

METHODS AND MATERIALS

Four breast carcinoma cell lines isolated from the primary tumor (21NT, 21PT) and metastases (21MT-1, 21MT-2) of a single patient were exposed to cumulative radiation doses of 30 Gy yielding cell lines designated-IR with respect to their parent. The irradiated lines were then compared to their parent for serum-and growth factor-requirements under defined media conditions, ability to proliferate in soft agar, concentration of TGF-alpha in conditioned medium, and radiosensitivity.

RESULTS

The irradiated lines showed no change in proliferative doubling times under serum- and growth factor-supplemented media conditions. A single line, 21MT-1-IR, acquired a limited ability to proliferate in serum-and growth factor-deplete medium with a day 2-4 doubling time of 44.5 hr. Three lines, 21MT-1-IR, 21MT-2-IR, and 21NT-IR, formed colonies in soft agar in contrast to none of the unirradiated parent lines. There were significant 6-8 fold increases in conditioned media TGF-alpha concentrations for 21MT-2-IR and 21NT-IR cells. The 21MT-1-IR and 21NT-IR cells were significantly less radiosensitive than their respective parent lines. This decrease in radiosensitivity appeared to be at least partially mediated by a released factor as the radiosensitivity of 21MT-1 cells was significantly decreased by pre-incubation with conditioned medium from 21MT-1-IR cells.

CONCLUSION

Radiation-induced changes in growth phenotype vary with respect to clonal origin of the cell line and may influence the radiosensitivity of surviving clonogens after fractionated treatment.

Determination of tertatolol enantiomers in biological fluids by high-performance liquid chromatography

A stereospecific high-performance liquid chromatographic method for the quantification of (-)- and (+)-tertatolol in plasma and urine is described. The method involves solid-phase extraction followed by derivatization with S(+)-naphthylethylisocyanate to form the urea derivative, which is more sensitive to fluorescence detection. The separation of the diastereomeric derivatives was performed by reversed-phase high-performance liquid chromatography. Fluorimetric detection (lambda excitation = 220 nm, lambda emission = 320 nm) allows the quantification of tertatolol enantiomers down to 6 ng/ml. The assay was used to study the pharmacokinetic profile of tertatolol enantiomers following oral administration of racemic tertatolol; preliminary results suggest enantioselective absorption and/or disposition of tertatolol.

Pharmacological study in vivo of the new topical anti-inflammatory steroid 21-thiol-9 alpha-fluoro-11 beta,17 alpha-dihydroxy-16 alpha-methyl-3,20-dione-21-acetylamino cysteine

The pharmacological evaluation, using animal models, of 21-thiol-9 alpha-fluoro-11 beta, 17 alpha-dihydroxy-16 alpha-methyl-3,20-dione- 21-acetylamino cysteine (CMJ), a new steroidal anti-inflammatory compound, is reported. The results obtained show a significant anti-inflammatory activity for CMJ. Comparison with dexamethasone indicates that CMJ is about 9 to 10 times less active in vivo. Of particular interest, however, is the dissociation of local and systemic activities of CMJ, since this compound was shown to be practically devoid of systemic activity (about 970 times less active than dexamethasone) after subcutaneous administration in rats. It is therefore expected that the topical use of CMJ in therapy may not cause the side effects provoked by many of the corticosteroids currently used.

Interaction of tertatolol with rifampicin and ranitidine pharmacokinetics and antihypertensive activity

The interaction of the new beta-receptor antagonist tertatolol with rifampicin and ranitidine was investigated in ten patients with arterial hypertension (WHO stages I-II). They were treated orally with a single dose of tertatolol 5 mg alone and, after randomized allocation, with ranitidine 150 mg twice daily or rifampicin 600 mg once daily for 1 week each (tertatolol 5 mg was concurrently administered on the seventh day of the treatment phases). Following each therapeutic phase, circadian blood pressure values as well as kinetic parameters were obtained. On treatment with tertatolol alone, maximum plasma concentrations were 123.7 +/- 32.4 ng/ml (mean +/- SD) and were reached after 1.95 +/- 1.77 hours. The tertatolol elimination half-life was 9.0 +/- 7.1 hours. Coadministration of ranitidine did not significantly alter the kinetic parameters and antihypertensive effect of tertatolol. Rifampicin, however, decreased the maximum plasma levels of tertatolol to 80.6 +/- 18.5 ng/ml and markedly shortened the elimination half-life to 3.4 +/- 2.6 hours (p less than 0.01 compared with tertatolol alone). Urinary excretion of parent tertatolol and unchanged 4-hydroxy tertatolol was decreased under rifampicin, and a tendency to a reduction in the effect of tertatolol on circadian blood pressure values was observed. Twenty-four hours after administration, the heart rate in those patients on tertatolol alone (68 +/- 6 beats/min) was lower than in those on tertatolol plus rifampicin (74 +/- 7 beats/min). In conclusion, a pronounced pharmacokinetic interaction, with a limited consequence in terms of pharmacodynamic effects, was found in the present study when tertatolol was administered with rifampicin, but not with ranitidine.

[Longterm results of McIntosh hemiarthroplasty of the knee in patients with rheumatoid arthritis of the knee]

A series of 35 knees operated on between 1967 and 1977 was reviewed. The follow up of 5 years or longer revealed over 40% of excellent and good results. The analysis of over 50% of poor results is suggestive of inadequate indications for hemiarthroplasty of the knee. In authors opinion Mc Intosh procedure should be still performed providing the indications are very accurate.

Stereoselective blockade of alpha-adrenoceptors by berbine derivatives

The effects of the two enantiomers of berbine (5,6,13,13a-tetrahydro-8H-dibenzo[a,g]quinolizine) and of derivatives obtained by introducing various substitutions on aromatic rings were investigated on alpha 1- or alpha 2-adrenoceptor subtypes. Binding studies carried out on rat cerebral cortex membranes using [3H]prazosin or [3H]yohimbine showed that the affinities of the (+) and (-)enantiomers for alpha 1 and alpha 2 binding sites were different and were differently modified by substitutions added to the berbine nucleus, leading to alpha 1- and alpha 2-selective compounds. Experiments performed on the isolated rat aorta and in pithed rats in vivo demonstrated the alpha-blocking property of berbine derivatives and confirmed the stereoselectivity of the effects of the (+) and (-)enantiomers on alpha 1- and alpha 2-adrenoceptor subtypes.

Pharmacokinetics of veralipride after chronic administration in humans

A pharmacokinetic study of veralipride (N-[(1-allyl-2-pyrroli dinyl)methyl]-5-sulfamoyl-o-veratramide) was performed in healthy volunteers during a chronic administration. The pharmacokinetic model based on the hypothesis of a double site for drug absorption, previously used after a single-dose oral administration, was developed to fit the data obtained after chronic administration. The empirical model used allows correct depiction of the behavior of the drug in the body, especially secondary peaks. According to the results, veralipride pharmacokinetics did not show any change upon chronic administration.

A double-peak phenomenon in the pharmacokinetics of veralipride after oral administration: a double-site model for drug absorption

Equal doses of veralipride have been given to 12 healthy volunteers by three different administrations--intravenous infusion, oral solution, and oral capsules--in a randomized cross-over design. After the intake of the solution, but not after infusion or capsules, two maximum plasma concentrations have been observed and interpreted, according to a double-site model for drug absorption.

Quantitative determination of tertatolol in biological fluids by gas chromatography-mass spectrometry

Quantitative determination of tertatolol concentrations in plasma and urine was performed by gas chromatography-mass spectrometry in the chemical-ionization mode with ammonia after successive extractions of the beta-blocking drug in alkaline, acid and final alkaline medium. [2H9]Tertatolol, isotopically stable under the operating conditions employed, was used as an internal standard, thus allowing quantities of 1 ng/ml to be specifically determined. Overall analytical error was less than 10%. Prior to isothermal chromatography at 240 degrees C on a column packed with 3% SE-30, both compounds were silylated with bis(trimethylsilyl)trifluoroacetamide. Detection was performed by monitoring the quasimolecular ions of tertatolol, m/z 368 and m/z 377, for the [2H9]tertatolol in the chemical-ionization mode with ammonia. The calibration curves obtained had linear characteristics for the concentration range 1-1125 ng/ml.

Quantitative analysis of veralipride in plasma and urine by gas chromatography-mass spectrometry and gas chromatography with flame-ionization detection

A highly sensitive and selective quantitative assay for unchanged veralipride has been developed. The compound is extracted from alkalized samples (plasma or urine) with dichloromethane and converted to its trimethylated derivative by reaction with trimethylanilinium hydroxide. The reaction mixture is then chromatographed on a 3% OV-1 column. Trimethylated derivatives of plasma samples were assayed by selected-ion monitoring in the chemical-ionization mode and quantified by comparing the intensity of the quasi-molecular ion m/z 426 (M + H) with the intensity of the corresponding ion from trideuterated internal standard, m/z 429 (M + H). Flame-ionization detection was used for the assay of urine samples. The peak height ratio of trimethylated veralipride over trimethylated sulpiride, the internal standard, was used for quantitation of urine samples. A relative standard deviation of less than 10% was found when quantifying 10 ng/ml veralipride in plasma or 1 microgram/ml in urine.

Primary dose-dependent pharmacokinetic study of veralipride

A dose-dependent pharmacokinetic study of veralipride (a new post-menopausal "hot flushes" regulator) was developed in humans after oral solution administration (100, 150, 200, and 250 mg). In most cases, two maxima of plasma drug concentrations occurred, probably due to a double intestinal site of absorption. From model independent pharmacokinetic parameters, it can be concluded that a linearity in the tested range doses exists.