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  • Scalp hair  (3)
  • Intraventricular conduction  (2)
  • 1
    ISSN: 1432-069X
    Keywords: Scalp hair ; Haloperidol ; Segmental analysis ; Dosage history ; Melanin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report a method for determining haloperidol concentration in human scalp hair and discuss a possible linkage of haloperidol excretion into hair with the hair pigment melanin. First, an animal study was conducted to support the idea that hair contains amounts of haloperidol corresponding to the doses given and pigmented hair contains much more drug than does unpigmented hair. The haloperidol concentration was measured using a radioimmunoassay technique after hairs were dissolved in 2.5 N NaOH solution and the drug extracted. Pigmented and albino rats, whose hair from an area on the back had been removed beforehand by plucking, were administered either 1,3, or 10 mg of haloperidol (i.p.) per kg body weight every day for 3 weeks. At the end of the administration period hair which had newly grown on the denuded area was plucked and collected. In each of the two groups classified by hair color the drug levels in the hair correlated with the doses given; however, the concentrations in the hair from the albino rats were much lower than those in the hair from the pigmented rats (which was less than 8.5%). Second, black and white hair was collected from each of seven human subjects with grizzled hair, who were receiving or had been administered haloperidol at fixed daily doses for more than 1 month, and the concentration of haloperidol in each type of hair was measured. In the same subject the concentration in the white hair was found to be much lower than that in the black (less than 10%). In three subjects the dosage had been changed before the hair samplings, and segmental analysis of the distribution of haloperidol in the black hair revealed that the dosage history was imprinted along the length, assuming a hair growth rate of 1 cm/ month; the distribution of drug along the white hair less obviously corresponded to the dosage. Third, another keratinized tissue, nail, was collected together with hair samples from 20 patients and the haloperidol level in the nail was measured and compared with that in the hair. The concentration of haloperidol in nail is only about 3.4% of that in hair. Taken together these results suggest that the mechanism for excreting haloperidol into hair is closely linked with that for the hair pigment melanin.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1912
    Keywords: Antidepressants ; Canine myocardial infarction ; Intraventricular conduction ; Arrhythmia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of mianserin, a tetracyclic antidepressant, and adinazolam, a new triazolobenzodiazepine which has antidepressant activity, on intraventricular conduction and the incidence of arrhythmias induced by programmed ventricular stimulation were studied in the dog heart after myocardial infarction and compared to the effects of amitriptyline, a standard tricyclic antidepressant. Amitriptyline at a dose of 1 mg/kg significantly slowed ventricular conduction in a frequency-dependent manner and at doses of 2 and 3 mg/kg significantly slowed ventricular conduction in infarcted ventricular myocardium. Amitriptyline also significantly slowed ventricular conduction in normal myocardium. Amitriptyline increased the incidence of ventricular arrhythmias induced by the programmed ventricular stimulation and prolonged the intraventricular delayed conduction resulting in re-entrant ventricular arrhythmia. On the other hand, mianserin and adinazolam at doses of 1–3 mg/kg had no significant effects on intraventricular conduction in infarcted and normal myocardium and on the incidence of arrhythmias induced by programmed ventricular stimulation. From these results, we can expect that mianserin and adinazolam may have a much lower cardiac toxicity than amitriptyline.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1912
    Keywords: Na+ and Ca++ channel blocker ; Ventricular arrhythmia ; Intraventricular conduction ; Refractory period ; Myocardial infarction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Antiarrhythmic and electrophysiological effects of SD-3212, a novel antiarrhythmic agent, which has both Na+ channel and Ca++ channel blocking activites, were compared with those of its (+)-stereoisomer, SD-3211, which has only a Ca++ channel blocking activity, and bepridil, a known Ca++ channel blocker with additional Na+ channel blocking activity, using the two-stage coronary ligation induced arrhythmia (24h after the ligation of the left anterior descending coronary artery) and 7 day-old myocardial infarcted hearts in anaesthetized dogs. SD-3212 showed a dose-dependent antiarrhythmic effect on the two-stage coronary ligation induced arrhythmia. SD-3212 at a dose of 3 mg/kg reduced the arrhythmic ratio, i.e. ectopic beats per min divided by the sum of ectopic beats and sinus beats per min, significantly from 1 up to 12 min after the administration. Neither bepridil (1–6 mg/kg) nor SD-3211 (1 mg/kg) had an antiarrhythmic effect. SD-3212 (0.3–3 mg/kg) prolonged both the conduction time in the normal myocardium and the delayed potential in the infarcted myocardium in the 7 day-old myocardial infarcted hearts in anaesthetized dogs in a dose-dependent manner. This effect of SD-3212 was shown at coupling intervals of 150–1000 ms increasing with decreasing interval. In this respect, SD-3212 is similar to drugs which show fast recovery of Vmax from use-dependent block such as lidocaine. Bepidril (1–6 mg/kg) also prolonged these parameters in a dose-dependent manner, however, the prolongation induced by bedripil was limited to shorter coupling intervals as compared with that induced by SD-3212. SD-3212 (0.1–1 mg/kg) did not show this prolonging effect. SD-3212 increased the refractory period in the infarcted zone to a small extent (not significantly) at all strengths tested between 0.5–4 mA and also in the normal zone between 0.2–1 mA to an even lesser extent than in the infarcted zone. Bepridil produced a significant increase of refractory period in the infarcted zone. In the normal zone, bepridil produced a non-significant, but greater increase of the refractory period as compared with SD-3212. SD-3211 did not affect the refractory period in the infarcted zone or in the normal zone. None of the three drugs produced a significant change in the excitation threshold. Thus, SD-3212 showed electrophysiological properties of a drug with fast recovery kinetics without producing a significant increase of refractory period, and these properties are very similar to those of class Ib antiarrhythmic agents such as lidocaine. The present study suggests that there might be a possibility of SD-3212 to become a safe and unique antiarrhythmic agent with suppresses both Na+ and Ca++ inward current.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 47 (1994), S. 195-202 
    ISSN: 1432-1041
    Keywords: Ofloxacin ; Haloperidol ; Scalp hair ; time marker ; dosage history ; HPLC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Hair samples were obtained 1–5 months after ingestion of the antimicrobial ofloxacin, which had been given for 1 or 3 days at the commencement of haloperidol administration, or when its dosage was reduced. The axial distribution of ofloxacin, haloperidol and its active metabolite, reduced haloperidol, was analysed in segments from single strands of hair. Ofloxacin was detected where the content of haloperidol and reduced haloperidol along the hair shaft showed a sharp change, corresponding to the change in dose. When we matched the time scale of the dosage history to the growth rate, which was estimated using ofloxacin as the time marker, the distribution of the haloperidol and reduced haloperidol precisely coincided with the rise and fall in the dose of haloperidol. These findings demonstrate that ofloxacin can serve as a time marker when drug distribution along the hair shaft is used to obtain the drug exposure history of an individual.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 40 (1991), S. 581-584 
    ISSN: 1432-1041
    Keywords: Scalp hair ; ofloxacin ; dosage history ; hair growth rate ; index of exposure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Several strands of hair were collected from each of patients who had been taking ofloxacin against bacterial infections some time in the past. In 10 out of total 14 subjects studied the drug was detected only in the hair portions corresponding to the administration period with the assumption of the hair growth rate of about 1 cm/month. Even in a subject who had received 300 mg/day of ofloxacin only for two days the drug could be detected in the corresponding portion. In 3 subjects the drug was detected in some other portion(s) than the corresponding ones. This might be due to the uncertainty of having used the drug on the other occasion. Only in one subject the dosage history could not be deduced from the drug distribution along hair length. In 3 subjects, who had taken the drug within 1 month, hair samples were collected every month for 3 or 4 consecutive months. The front of drug appearance in hair was clearly shown to move outwards along hair shaft every month at a pace of 1–1.5 cm/month. These results suggest that ofloxacin is excreted into human scalp hair, captured there and moves outwards along the hair shaft at its own growth rate. This leads to the concept that the distribution of ofloxacin along hair length can be used for knowing the individual exposure or non-exposure to the drug, and even for knowing hair growth rate when the innoculation(s) of the drug is strictly supervised and recorded.
    Type of Medium: Electronic Resource
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