Biomedical subjects

R L Manfredi

Publications and source records attributed to R L Manfredi.

21 records · Page 2Linked to original sources

PubMed1986

Comparison of short and long half-life benzodiazepine hypnotics: triazolam and quazepam.

Two benzodiazepine hypnotics, triazolam, 0.25 mg, with a short elimination t1/2, and quazepam, 15 mg, with a long t1/2, were evaluated in 22-night sleep laboratory studies. Quazepam improved sleep significantly during both short- and intermediate-term use. Daytime sleepiness, which decreased with continued use, was the side effect most often associated with quazepam dosing. In contrast, triazolam dosing did not significantly improve any of the major sleep efficiency parameters, and there was a rapid development of tolerance for the drug's slight initial effectiveness. In addition, there were a number of behavioral side effects including amnesia, confusion, and disinhibition. Withdrawal of triazolam was associated with sleep and mood disturbances (rebound insomnia and rebound anxiety), whereas quazepam exerted carryover effectiveness. Thus the data in this study show that the 0.25 mg dose of triazolam, which is being prescribed increasingly, has a profile of side effects that is similar to that of the 0.5 mg dose.

Adult↗

PubMed1986

Narcolepsy/cataplexy. III: Nocturnal sleep and wakefulness patterns.

Nocturnal sleep and wakefulness patterns of 50 patients with narcolepsy and cataplexy were compared to those of 50 control subjects. A sleep onset REM period (SOREM) occurred in 22 (44%) of the patients but in none of the controls. Comparisons among patients showing a SOREM, patients without this abnormality, and controls demonstrated that the timing, number and duration of the remaining REM periods did not differ across the three groups. Thus, the basic REM sleep disturbance in narcolepsy appears to relate to the timing of onset of the initial REM period. This finding lends further support to the theory of dual control of REM-NREM cycling. While narcoleptics took significantly less time to fall asleep, they had significantly more awakenings, wake time after sleep onset and total wake time. The disturbed sleep experienced by patients could not be accounted for by the presence of a sleep onset REM period or the use of medication. Nocturnal wakefulness appeared to be distributed in a regular oscillating manner throughout the recording period similar to the pattern of daytime vigilance previously reported in normal subjects. Thus, typical nocturnal dampening of daytime ultradian vigilance rhythms may be lost in the narcoleptic patient.

Adult↗

PubMed1981

Inhibition of theophylline metabolism by long-term allopurinol administration.

Administration of an oral dose of allopurinol (300 mg every 12 hr) for 14 consecutive days increased the mean theophylline area under the curve (AUC) 27% and mean theophylline half-life (t1/2) 25%, whereas the mean theophylline clearance (Cl) decreased 21%. Allopurinol did not alter either apparent volume of distribution (aVd) or gastrointestinal absorption (Cmax and tmax) of theophylline. After 28 consecutive days of allopurinol administration, theophylline disposition was the same as that on day 14. Thus, given in a dose of 300 mg every 12 hr for 14 or 28 days, allopurinol inhibits theophylline metabolism, despite the failure of allopurinol in lower doses given for only 7 days to alter theophylline disposition. These results emphasize the need to investigate several different doses and durations of administration within therapeutic ranges before firm conclusions can be drawn concerning the influence of one drug on the disposition of another.

Adult↗