Aminophylline and respiratory muscle interaction in normal humans.

The effects of intravenous infusion of aminophylline on respiratory muscle interaction were examined in seven normal subjects breathing at rest. Rib cage (RC-Ap) and abdominal (AB-Ap) volume displacements, pleural (Ppl), gastric (Pg), and transdiaphragmatic (Pdi) pressure swings, and electromyographic activity of the diaphragm (Edi) and the parasternal (Eps) muscles were measured under control and during infusion of either aminophylline or placebo in a double-blind randomized manner. Compared with placebo, aminophylline induced an increase in ventilation (p < 0.

Effects of oxcarbazepine and carbamazepine on the central nervous system: computerised analysis of saccadic and smooth-pursuit eye movements.

Oxcarbazepine (OXC) is a new anti-epileptic agent structurally related to carbamazepine (CBZ). OXC seems to have a similar efficacy and a better tolerability profile than CBZ. In the present study we compared the subclinical side-effects on the CNS of OXC and CBZ using a computerised analysis of saccadic and smooth-pursuit eye movements.

PKRD: a pharmacokinetic program for least-squares and bayesian analysis of repeated-dose pharmacokinetic curves.

A microcomputer program is presented which analyses multiple-dose pharmacokinetic curves using either a least-squares nonlinear analysis or a bayesian fit. The least-squares subroutine is designed to fit retrospective pharmacokinetic curves and can generate the so-called population pharmacokinetic parameters using the Standard Two-Stage method. The bayesian subroutine can instead be used prospectively to individualise the dosage regimen of a patient based on the concentrations measured in the initial phases of the drug treatment.

[The effects of the acute administration of atrial natriuretic peptide on the mechanisms regulating diuresis and natriuresis in the essential hypertension patient].

The authors investigated the role of atrial natriuretic peptide (alpha-hANP 99-126) in essential hypertension by evaluating some hemodynamic and renal effects of acute peptide infusion (1 micrograms/kg for 1 min + 50 ng/kg for the following 20 min) in fourteen subjects: eight mild to moderate, untreated, essential hypertensives (EH) and six normotensive (N) controls, during 2 hour-clearance periods, the 1st after ANP infusion, the 2nd during placebo (PL) administration. The double-blind study was carried out after the patients had rested and fasted overnight. It showed no significant changes in heart rate (HR); instead, compared with placebo, mean blood pressure (MBP) decreased significantly in both groups, beginning from the 3rd min after ANP infusion was begun (N: PL = 87.

External quality assessment in therapeutic drug monitoring: an Italian experience.

Pharmacontrol is an external quality assessment (EQA) for therapeutic drug monitoring initiated in Italy in 1986 on regional basis. Since then, interest and involvement being on a national level, participation has expanded to some 180 laboratories currently. The EQA concerns assays for the drugs most frequently monitored in Italy (seven drugs until 1989, 13 at present).

Bioavailability of intramuscular ciclosporin in the pig.

We conducted a cross-over single-dose pharmacokinetic study in 4 pigs to measure the bioavailability of ciclosporin (CS) after intravenous and intramuscular administration. Each animal was given 5 mg/kg i.v.

[Azlocillin in the treatment of pulmonary infections in patients with cystic fibrosis: plasma concentrations and therapeutic indications].

Azlocillin plasma concentrations have been studied in 10 cystic fibrosis patients suffering from chronic pulmonary infections with Pseudomonas aeruginosa. Patients were given single i.v.

Predictive performance of pharmacokinetic methods for phenytoin dosing: a multi-center evaluation in 282 patients with epilepsy.

A retrospective study was conducted in 282 patients with epilepsy to assess the predictive performance of pharmacokinetic methods for individualizing dosage of phenytoin. Two population-based dosing methods (population clearance method and bayesian feedback method) and one individual-based method (the so-called linearized Michaelis-Menten method) were evaluated, when applicable, for single-point and/or 2-point dose predictions of phenytoin. In single-point predictions, we found a generally low percentage of dose calculations falling inside the +/- 10% range (48.

Pyrrolidone carboxylic acid in acute and chronic alcoholism. Preclinical and clinical studies.

2-Pyrrolidone-5-carboxylic acid (PCA) is a cyclic derivative of glutamic acid, physiologically present in mammalian tissues. We herein report preclinical pharmacology experiments showing that PCA releases GABA from the cerebral cortex of freely-moving guinea-pigs and displays anti-anxiety effects in a simple approach-avoidance conflict situation in the rat. In clinical pharmacology experiments, PCA significantly shortens the plasma half-life of ethanol during acute intoxication.

Usefulness of basal catecholamine plasma levels and clonidine suppression test in the diagnosis of pheochromocytoma.

In the present paper we report our experience on the utility of basal plasma catecholamine (CA) measurement and of the clonidine-suppression test in the diagnosis of pheochromocytoma. Basal noradrenaline (NA) and adrenaline (A) were assayed in plasma samples of 27 subjects affected by pheochromocytoma. When compared to basal values obtained in hypertensive patients without pheochromocytoma, one or both the CA resulted pathologically elevated in all patients except one.

Long-term treatment with sodium valproate: monitoring of venous ammonia concentrations and adverse effects.

Adverse effects and venous blood ammonia concentrations were monitored over a period of 7 months in patients with epilepsy treated with valproate (VPA). During the 1st, 4th, 12th, 20th, and 28th weeks of therapy, blood samples for analysis of ammonia and anticonvulsants were taken immediately before the morning dose of VPA as well as 2 h after dosing. In all, 40 patients completed the follow-up; 16 of these (Group 1) received VPA alone, while the remaining 24 (Group 2) were treated simultaneously with VPA and other anticonvulsants (phenobarbital, phenytoin, and/or carbamazepine).

[Pharmacokinetics of oral theophylline. Comparison between asthmatic and cystic fibrosis patients].

The pharmacokinetics of oral theophylline at steady-state were comparatively investigated in 13 asthmatic patients and in 10 patients with cystic fibrosis (CF). In all patients, the drug was administered twice daily as slow-release tablets. The total daily dose of theophylline ranged from 10.

The role of lithium carbonate in the management of hemolymphoblastosis: estimation of plasmatic and erythrocyte lithium levels.

Twelve patients affected by hemolymphoblastosis were treated with lithium carbonate in order to attenuate neutropenia induced by anticancer drugs. Controls were chosen among patients who had not received lithium treatment after cytostatic therapy. We estimated plasmatic and erythrocyte lithium levels and determined the Erythrocyte lithium rate (ER), i.

Effect of associated antiepileptic treatment on valproate-induced hyperammonemia.

It has recently been shown that acute changes of venous blood ammonia (NH3) may predict short-term adverse effects of valproic acid (VPA). In the present study, the time course of NH3 concentration after a single oral dose of VPA (800 mg) was monitored in 68 epileptic patients. Patients were classified into four groups: previously untreated patients (group A, n = 21), patients under treatment with either phenobarbital (group B, n = 14) or phenytoin (group C, n = 13) or both (group D, n = 20).

Acute changes of blood ammonia may predict short-term adverse effects of valproic acid.

Valproic acid (VPA) was given to 24 epileptic patients who were already being treated with other antiepileptic drugs. A standardized loading dose of VPA was administered, and venous blood was sampled at 0, 1, 2, 3, and 4 hours. Ammonia (NH3) was higher in patients who, during continuous therapy, complained of drowsiness (7 patients) than in those who were symptom-free (17 patients), although VPA plasma levels were similar in both groups.