Relative efficacy of drugs for the treatment of sleepiness in narcolepsy.
(1/14)
A survey was conducted on 10 polysomnographic studies on the pharmacologic treatment of the sleepiness of narcolepsy. Three studies employed the MSLT and 7 employed the MWT as their polygraphic measure of sleep tendency. Statistically and clinically significant therapeutic changes were apparent for pemoline, modafinil, dextroamphetamine and methylphenidate. Codeine, ritanserin and protriptyline did show statistically significant effects. The common feature among the drugs that did produce clinically significant improvements seems to be facilitatory action on central catecholaminergic transmission. Within this group of drugs, only methylphenidate and dextroamphetamine brought MWT sleep latencies to approximately 70% of normal levels. (+info)
Association of changes in norepinephrine and serotonin transporter expression with the long-term behavioral effects of antidepressant drugs.
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Protriptyline treatment of sleep hypoxaemia in Duchenne muscular dystrophy.
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Protriptyline 20 mg daily reduced the total time spent in rapid eye movement sleep in an open study in four subjects with Duchenne muscular dystrophy. Sleep related hypoxaemia and episodes of desaturation were reduced. Anticholinergic side effects were prominent, however, in these patients, precluding its use for regular treatment. (+info)
Changes in day and night time oxygenation with protriptyline in patients with chronic obstructive lung disease.
(4/14)
The effect of protriptyline, a tricyclic antidepressant, on sleep architecture, nocturnal arterial oxygen desaturation, pulmonary function, and diurnal arterial blood gases was investigated in an open study of 14 patients with stable chronic obstructive lung disease. Daytime and overnight measurements were made before and 2 and 10 weeks after they started protriptyline (20 mg daily at bedtime). Two patients had to be excluded before the second visit and one before the third visit because of changes in treatment for their chest disease. Protriptyline caused mouth dryness in all patients and dysuria in six men. With protriptyline there were no significant changes in total sleep time, sleep period time, or the percentages of total sleep time occupied by stage I-II and stage III-IV sleep. The mean (SEM) percentage of total sleep time spent in rapid eye movement (REM) sleep decreased from 11.1 (1.7) to 4.6 (0.7) at two weeks and to 4.2 (1.0) at 10 weeks. After protriptyline the time spent during sleep with an arterial oxygen saturation (SaO2) below each 5% increment above 65% was less than the baseline time; the lowest SaO2 (%) reached during sleep increased from 64.5 (1.7) to 72.7 (2.1) at 2 weeks and to 77.4 (2.1) at 10 weeks. Lung volumes and expiratory flows were unchanged during the study. Daytime arterial oxygen tension (PaO2) increased from 57 (1.4) mm Hg before treatment to 62 (1.9) mm Hg at 2 weeks and to 66 (1.9) mm Hg at 10 weeks (7.6 (0.2), 8.3 (0.3), 8.8 (0.3) kPa). Carbon dioxide tension fell from 52 (2.3) mm Hg to 49 (1.4) mm Hg at 2 weeks and to 48 (2.0) mm Hg at 10 weeks (6.9 (0.3), 6.5 (0.2), 6.4 (0.3) kPa), but these changes were not significant. These results suggest that protriptyline may benefit patients with chronic obstructive lung disease by reducing the sleep induced falls in SaO2 and improving diurnal PaO2; a controlled trial is now required. (+info)
Effects of protriptyline on sleep related disturbances of breathing in restrictive chest wall disease.
(5/14)
The effects of protriptyline on sleep stage distribution and gas exchange have been assessed in eight patients with nocturnal hypoventilation secondary to restrictive chest wall disease. At a dose of 10-20 mg taken when they retired the total sleeping time was unaltered but the proportion of rapid eye movement (REM) sleep fell from 22% to 12% (p less than 0.05). The total time spent at an arterial oxygen saturation of less than 80% decreased (p less than 0.01) and the magnitude of the fall correlated with the reduction in REM sleep (r = 0.67, p less than 0.05). There was also a reduction in the maximum carbon dioxide tension reached during the night (p less than 0.01). The arterial oxygen tension measured diurnally increased (p less than 0.05) from a median of 8.0 kPa (60 mm Hg) to 9.0 kPa (67.5 mm Hg), but the carbon dioxide tension and base excess were unchanged. Anticholinergic side effects were experienced by most patients but did not limit treatment. (+info)
Interaction of cannabis and general anaesthetic agents in mice.
(6/14)
1 A cannabis extract (I) (in a concentration equivalent to 10 mg Delta(9)-tetrahydro-cannabinol(THC)/kg) prolonged pentobarbitone anaesthesia in mice maximally 20 min to 2 h after medication. The effect was still significant after 8 h, but less than at 2 hours.2 The cannabis extract (I) (equivalent to 10 mg Delta(9)-THC/kg) prolonged both pentobarbitone and ether anaesthesia in mice when administered 20 min before the anaesthetic. After eight consecutive daily doses of cannabis, the pentobarbitone anaesthesia was still significantly longer than a control group, while ether anaesthesia was not significantly prolonged.3 A second cannabis extract (II) with a different ratio of cannabinoids (also administered in dosage equivalent to 10 mg Delta(9)-THC/kg) failed to affect pentobarbitone anaesthesia in mice. This extract presented about 4% the dose of cannabidiol as extract I.4 Delta(8)-THC, Delta(9)-THC and cannabidiol prolonged pentobarbitone anaesthesia with cannabidiol being generally more active than Delta(9)-THC. Cannabinol (10 mg/kg) was inactive.5 The effects of cannabidiol and Delta(9)-THC were found to be additive, and there was a consistent trend for cannabinol to reduce the effectiveness of Delta(9)-THC and cannabidiol when given in combination.6 Premedication with phenoxybenzamine, phentolamine, propranolol, iproniazid, protriptyline, desipramine, reserpine, alpha-methyl tyrosine or parachlorophenylalanine did not affect the extract I-induced prolongation of pentobarbitone anaesthesia.7 It is concluded that cannabis may affect pentobarbitone and ether anaesthesia in mice at least partially by a direct depressant effect, and that the cannabis-induced prolongation of anaesthesia is probably unrelated to any effect on central 5-hydroxytryptamine or catecholamine neurones. (+info)
Anti-nociceptive effect of tricyclic anti-depressants following intrathecal administration.
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The anti-nociceptive effects of three tricyclic anti-depressants (desipramine, protriptyline, fluoxetine) were evaluated in mice following intrathecal administration. Nociceptive behavior was produced by intrathecal administration of Substance P and measured for 60 seconds following subcutaneous and intrathecal administration of vehicle and increasing doses of the drugs being tested. Systemically administered protriptyline produced dose related antinociception in this paradigm. A similar effect was seen following systemic desipramine; while fluoxetine was inactive systemically. Both protriptyline and desipramine given intrathecally were antinociceptive while fluoxetine had a biphasic effect, being analgesic only at low doses. These results indicate that tricyclic antidepressants may produce analgesia at the spinal level in rodents. This action may be related to the therapeutic success of tricyclic antidepressants in chronic pain syndromes. (+info)
Determination of bethanidine in plasma by liquid-chromatography with a microbore reversed-phase column.
(8/14)
In this novel method for quantifying bethanidine in plasma, after a multi-step extraction of bethanidine and internal standard from 2.0 mL of plasma, the drugs are separated on a "microbore" C18 reversed-phase column and quantified by their ultraviolet absorbance at 210 nm. The isocratic chromatographic separation takes about 15 min with use of an ion-pairing regent in the mobile phase (acetate buffer/acetonitrile, 9/1 by vol) and a flow rate of 0.25 mL/min. Sensitivity is increased relative to conventional columns, and solvent consumption is reduced by 90%. The standard curve is linear to at least 5 mg/L, and the detection limit is 0.02 mg/L. The within-run precision of the method is excellent (CV 4%) at a midrange concentration of 1.25 mg/L. (+info)