Biomedical subjects

M Breda

Publications and source records attributed to M Breda.

At least 19 recordsLinked to original sources

PubMed1992

Determination of 3'-deamino-3'-[2(S)-methoxy-4-morpholinyl]doxorubicin, a new morpholinyl anthracycline, in plasma by high-performance liquid chromatography with fluorescence detection.

A sensitive and selective high-performance liquid chromatographic method for the determination of 3'-deamino-3'-[2(S)-methoxy-4-morpholinyl]doxorubicin and its possible 13-dihydro metabolite in human plasma has been developed. The plasma samples were buffered and the drugs and internal standard (doxorubicin) were extracted with diethyl ether-n-butanol, back-extracted into 0.3 M phosphoric acid, then analysed by reversed-phase liquid chromatography. Quantitation was achieved by fluorescence detection of the eluate. The linearity, precision and accuracy of the method were evaluated. No interference from blank plasma sample was observed. The suitability of the method for in vivo samples was checked by analysis of plasma samples drawn from female rats that had received repeated intravenous doses of the test compound.

Animals↗

PubMed1992

A study of the effects of rifabutin on isoniazid pharmacokinetics and metabolism in healthy volunteers.

The effect of repeated administration of rifabutin on the pharmacokinetics and metabolism of isoniazid was evaluated in 6 healthy volunteers. The subjects received on day 1 and 9 a single oral dose of 300 mg isoniazid and from day 2 to 8 a single daily oral dose of 300 mg rifabutin. Two out of 6 subjects were shown to be rapid acetylators. No significant modification of the plasma pharmacokinetic profiles of isoniazid and acetylisoniazid was found. Evidence exists in the present study for autoinduction of rifabutin metabolism; this is shown by the lower plasma concentrations obtained 24 h after the seventh dose as compared to the theoretical concentrations.

Acetylation↗

PubMed1991

Plasma morphine and morphine-6-glucuronide patterns in cancer patients after oral, subcutaneous, sublabial and rectal short-term administration.

Clinical studies on the effectiveness of morphine administered through different routes are contradictory. In order to further elucidate this point, the plasma concentrations of morphine and its 3- and 6-glucuronated metabolites were measured after short-term oral, sublabial, rectal and subcutaneous administration of the opiate. The bioavailability of free morphine and the 6-glucuronated active metabolite was comparable through the different routes. It was concluded that the choice of the route of morphine administration should be mainly guided by the needs of each individual patient.

Aged↗

PubMed1990

Effect of nifedipine on morphine-induced analgesia.

Experimental data show that opiates interfere with calcium influx in the cell and that some calcium-channel blockers are analgesic. We therefore studied the effect of the calcium-receptor blocker nifedipine on the analgesic effect of morphine in the rat, using tail-flick responses, and in humans, using measurements of the intensity of postoperative pain. In both the experimental animals and humans nifedipine significantly (P less than 0.001) increased the analgesic effect of morphine independently of any effect on the metabolism of morphine. Respiratory and cardiovascular functions were not significantly changed by nifedipine. The data indicate that Ca2+ is important in mediating the analgesic effects of opiates and suggest that calcium-receptor blockers might find a place in the treatment of pain.

Adult↗

PubMed1978