European journal of clinical pharmacology
-
Eur. J. Clin. Pharmacol. · Jan 1991
Pitfalls of pharmacokinetic dosage guidelines in renal insufficiency.
As the renal elimination of most drugs is closely correlated with the endogenous creatinine clearance, it is possible to use this parameter of kidney function to adjust drug dosage in renal failure. However, this simple procedure neglects possible changes in the volume of distribution, plasma protein binding, drug metabolism, intestinal absorption, and pharmacodynamics in renal insufficiency, as well as the occurrence of biologically active drug metabolites. Because of these uncertainties in critical cases the validity of the dosage calculated using the creatinine clearance should be checked by clinical surveillance and measurements of drug blood concentrations. Further, pharmacokinetic dosage guidelines based on the individual creatinine clearance may not be applicable to diuretics and drugs which have markedly differing kinetics of pharmacodynamic effects and blood levels.
-
Eur. J. Clin. Pharmacol. · Jan 1991
Randomized Controlled Trial Clinical TrialTransdermal fentanyl for the treatment of pain after major urological operations. A randomized double-blind comparison with placebo using intravenous patient-controlled analgesia.
Transdermal fentanyl 75 micrograms/h (Fentanyl-TTS) was compared with placebo in a randomized double-blind study in the early postoperative period, using 50 patients recovering from major urological operations. Analgesic efficacy was individually titrated with intravenous fentanyl by means of a PCA pump (demand dose 34 micrograms, lockout time 5 min). The test systems were applied 8 h before anaesthesia and were left in situ for 24 h. ⋯ Patient acceptance was high in both groups. Side-effects were of only minor intensity and did not differ between the two groups. In particular, there was no case of clinically relevant respiratory depression.
-
Eur. J. Clin. Pharmacol. · Jan 1990
Clinical pharmacokinetics of intravenous and oral 9-amino-1,2,3,4-tetrahydroacridine, tacrine.
The pharmacokinetics of 9-amino-1,2,3,4-tetrahydroacridine; tacrine, THA, was studied after intravenous administration and following the first and last oral doses of a seven week clinical trial involving 8 patients with amyotrophic lateral sclerosis, ALS. Two surgical patients given intravenous THA for reversal of postoperative sedation were also included. Plasma concentration of THA and in some cases the metabolite, 1-hydroxy-THA, were assayed using a selective and sensitive method with high performance liquid chromatography. ⋯ After seven weeks treatment with oral THA, plasma concentrations immediately prior to medication were below 10 ng/ml in three patients and above 100 ng/ml in two patients. At the same occasion the plasma metabolite concentrations considerably exceeded those of THA. THA medication was associated with side effects in the majority of the patients.
-
Eur. J. Clin. Pharmacol. · Jan 1989
Randomized Controlled Trial Clinical TrialEffects of clobazam and clonazepam on saccadic eye movements and other parameters of psychomotor performance.
The effects of two benzodiazepine anticonvulsants clobazam (20 mg) and clonazepam (2 mg) in a variety of psychomotor performance tests were compared in a placebo controlled double-blind acute oral dose study in ten healthy volunteers. Assessments included critical flicker fusion (CFF) threshold, the Sternberg memory scanning and choice reaction time (CRT), peak saccadic velocity (PSV) and visual analogue scales, all previously shown to be sensitive to the effects of benzodiazepines. ⋯ Clonazepam significantly increased memory scanning time compared to clobazam. Clobazam was remarkably free of cognitive and psychomotor side-effects.
-
Eur. J. Clin. Pharmacol. · Jan 1989
Inaccuracy in the doses of injectable medications dispensed from rubber-stoppered vials.
The literature of pharmacology often assumes that a full dosage is utilized when the contents of a vial have been administered by syringe. Five hundred discarded medication vials were assayed. The residues amounted to 1.98% to 8.81% of the listed dosages. ⋯ Although the amount of drug lost during preparation and administration may be of little therapeutic consequence, the discrepancy between intended and administered dosage is reflected in economic loss and pharmacological confusion. Pharmacological data should be adjusted for such losses. Medication wastage could be reduced by redesign of vials and alterations in practice of the administration.