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Drug binding in sera deficient in lipoproteins, albumin or orosomucoid.

The relative role of lipoproteins, albumin and orosomucoid in the serum binding variation of various drugs was examined by separate removal of these proteins. Lipoproteins were removed from serum by ultracentrifugation, albumin by affinity chromatography and orosomucoid by immunoprecipitation. Removal of the lipoproteins did not affect the serum binding of the acidic (phenytoin) and neutral (digitoxin) drugs tested, nor the basic drugs disopyramide, quinidine or propranolol. A reduction in binding of amitryptyline, nortriptyline, doxepin and desmethyldoxepin was observed. Removal of albumin did, with some exception for nortriptyline, not affect the serum binding of the basic drugs tested. A pronounced reduction in the binding of phenytoin and digitoxin was observed. Removal of orosomucoid did not affect the binding of the acidic and neutral drugs tested. A reduction in the binding of all the basic drugs tested was observed, especially for disopyramide whose binding almost disappeared. Quinidine, propranolol, phenytoin and digitoxin all bound to isolated lipoproteins, but the removal of lipoproteins had no effect on the total serum binding for these drugs. Hence, the use of deficient sera provides valuable information as to the quantitative role of the various proteins in drug binding, whereas studies using purified proteins are often necessary to examine the mechanisms of the drug protein interactions.

Humans↗

Release of gastrointestinal hormones in cardiodepressive shock.

In previous studies increased plasma levels of vasoactive intestinal polypeptide (VIP), somatostatin and pancreatic polypeptide (PP) were demonstrated in a porcine endotoxin shock model. Unchanged levels of gastric inhibitory polypeptide (GIP) and secretin point to a specific shock reaction of peptide release and not to a diffuse mucosal leakage. A porcine model of cardiodepressive shock was developed to enable discrimination to be made between a general low-flow state and endotoxin reaction. Infusion of the tricyclic antidepressive agent nortriptyline 15 mg/kg bodyweight resulted in a grave shock state. Increased plasma levels of somatostatin, PP and insulin were found. No increase in VIP levels could be demonstrated. Endotoxin given after nortriptyline administration resulted in the increase of VIP levels regularly seen during endotoxinaemia. VIP release during endotoxin shock is related to endotoxin and not to a general low flow state.

Animals↗

Accumulation and overflow of 3H following incubation of the guinea-pig gall bladder with [3H]-noradrenaline.

1 Strips of guinea-pig gall bladder readily accumulate (3)H following incubation in the presence of 5 x 10(-8) M (-)-[(3)H]-noradrenaline. This accumulation was reduced by lowering the incubation temperature (from 37 degrees to 23 degrees C), by cocaine (10(-6) M), by nortriptyline (10(-8), 10(-6) and 10(-4) M) and following incubation of the tissues with 6-hydroxydopamine (10(-3) M for 3 h). At 10(-6) M, (-)-noradrenaline and (-)-adrenaline, but not (-)-isoprenaline, inhibited the accumulation of (3)H.2 Following preloading of strips of guinea-pig gall bladder with 3.6 x 10(-7) M (-)-[(3)H]-noradrenaline for 1 h, the spontaneous overflow of (3)H was observed. Cocaine (10(-4) M), nortriptyline (10(-6) M), (-)-isoprenaline (10(-5) M), acetylcholine (10(-5) M) and adenosine 5'-triphosphate (ATP, 10(-4) M) had no effect on the spontaneous overflow of (3)H. KCl (10(-1) M), (-)-noradrenaline (10(-5) M), (-)-adrenaline (10(-5) M), and tyramine (10(-5) M) increased the overflow of (3)H. These results illustrate similar characteristics of the guinea-pig gall bladder to other noradrenergically-innervated tissues in accumulating and releasing (3)H following incubation in the presence of [(3)H]-noradrenaline.3 Following incubation in the presence of 3.6 x 10(-7) M (-)-[(3)H]-noradrenaline, field stimulation, at 5 Hz, of strips of gall bladder, in the absence or presence of 10(-6) M atropine, increased the overflow of (3)H and, simultaneously, induced contractions. The contractile responses to 5 Hz were smaller in the presence than in the absence of 10(-4) M lignocaine. Lignocaine (10(-4) M) reduced the overflow of (3)H evoked by field stimulation at 5 Hz. It is suggested that the contractile responses to 5 Hz are due to nerve stimulation and that the increased overflow of (3)H is due to the stimulation of noradrenergic nerves.4 The overflow of (3)H evoked by field stimulation at 5 Hz was unaltered and increased by propranolol (10(-6) M) and phentolamine (10(-6) M), respectively. Clonidine (5 x 10(-5) M) had no effect in the absence but reduced the amount of (3)H which overflowed in response to field stimulation at 5 Hz in the presence of 10(-6) M atropine. The contractile responses to field stimulation at 5 Hz were reduced by phentolamine (10(-6) M) or clonidine (5 x 10(-6), 10(-5) and 5 x 10(-5) M) whether or not atropine (10(-6) M) was present. These results illustrate the presence of postsynaptic alpha-adrenoceptors and suggest the presence of presynaptic alpha-adrenoceptors in the gall bladder of the guinea-pig.

Animals↗

Potentiation by TRH of the effect of antidepressants in the forced-swimming test, involvement of dopaminergic and opioid systems.

1. It has been shown that thyrotropin releasing hormone (TRH) can potentiate the effects of the antidepressant, imipramine, as measured by the mouse forced-swimming test. This potentiation is not associated with an increase of effective levels of noradrenaline in the synaptic clefts, but depends upon the integrity of opioid systems. The present study was designed to investigate: (a) the potentiation by TRH of the effects of other antidepressants, using the same test; (b) the possible involvement of other neuronal systems, such as the 5-hydroxytryptaminergic and dopaminergic systems; (c) the contribution of the opioid and dopaminergic systems to the potentiation of the actions of other antidepressants by TRH. 2. The effects of nortriptyline, amineptine, maprotiline, nomifensine and mianserin, but not that of clomipramine, were potentiated by TRH (2 mg kg-1, i.p.). The inhibitor of 5-hydroxytryptamine synthesis, p-chlorophenylalanine (PCPA), did not prevent the effect induced by imipramine plus TRH. Blockade of dopaminergic systems by gamma-butyrolactone (GBL) (37.5 mg kg-1, i.p.), alpha-methyl-p-tyrosine (AMPT) (125 mg kg-1, i.p.) and apomorphine (0.025 mg kg-1, i.p.) antagonized the effects induced by various antidepressants alone (at high, effective doses) or at lower ineffective doses in association with TRH. The effect induced by imipramine plus TRH was also blocked by sulpiride (16 mg kg-1, i.p.). Pretreatment with the opioid antagonist, naloxone, inhibited the effects induced by nomifensine plus TRH or mianserin plus TRH but not those induced by nortriptyline plus TRH, maprotiline plus TRH or amineptine plus TRH. When high active doses of the antidepressants were used alone, only the clomipramine effect was blocked by naloxone. 3. These data indicate that TRH is able to potentiate the effect not only of imipramine but of other antidepressants in the mouse forced-swimming test, although these other antidepressants act in various ways on cerebral amines. The antagonism of the effects induced by the antidepressants alone or in association with TRH after blockade of dopaminergic systems may indicate a reversal of the effect of the antidepressants by blockade of dopaminergic systems. Hence, the same mechanisms would be involved in the effects induced by antidepressants alone or in association with TRH, with respect to dopaminergic systems. However, different mechanisms of action seem to be responsible for the potentiation of TRH of the effect of the various antidepressants, since the involvement of the opioid systems varies according to the antidepressant tested.

5-Hydroxytryptophan↗

Anticholinergic activity in the serum of patients receiving maintenance amitriptyline or doxepin therapy.

The anticholinergic activity in serum of depressive patients receiving amitriptyline (50-300 mg/day) or doxepin (50-225 mg/day) was measured using a radioreceptor assay. In this method the membrane suspension prepared from rat brain was able to bind the potent muscarinic antagonist, quinuclidinyl benzilate. Using atropine as a standard, the antimuscarinic activity of several compounds can be measured in the serum of patients receiving drugs with anticholinergic effects or side-effects. The steady state serum levels of amitriptyline and doxepin and their desmethylated metabolites, nortriptyline and desmethyldoxepin were measured by radioimmunoassay in the same serum samples. The antimuscarinic activity in serum measured as atropine equivalents was 2.7 +/- 0.4 (S.E.M.) ng/ml in amitriptyline patients and 1.1 +/- 0.2 ng/ml in doxepin patients. There was a highly significant correlation (P less than 0.001) between amitriptyline (r = 0.92) and nortriptyline (r = 0.79) concentrations and serum antimuscarinic activity. The correlation was less clear, although statistically significant for doxepin (r = 0.42, P less than 0.05) and desmethyldoxepin (r = 0.58, P less than 0.01). The better correlation between serum drug levels and antimuscarinic activity in amitriptyline than in doxepin patients is probably due to the higher affinity of amitriptyline and its desmethylated metabolite to muscarinic receptors with the doses used in the present study. The method may have clinical applications e.g. in evaluation of excessive anticholinergic activity in patients.

Adult↗

Tricyclic antidepressants inhibit opioid receptor binding in human brain and hepatic morphine glucuronidation.

The opioid receptor binding in the human thalamic area was studied with U-69593 and naloxone as ligands for the kappa and mu receptors, respectively. The binding was inhibited by various tricyclic antidepressants including amitriptyline, nortriptyline, clomipramine and fluoxetine. The antidepressants tested had a slight selectivity for the kappa receptor type. The IC50-values for all tricyclic antidepressants tested were in the 10(-6) M concentration range. Morphine and tricyclic antidepressants are substrates of a liver microsomal uridine diphosphate glucuronyl transferase (UDPGT). The interaction of the tricyclic antidepressants with morphine glucuronidation was investigated in human liver microsomal preparations. All drugs inhibited the morphine UDPGT. In Dixon plots inhibition of the formation of morphine-3-glucuronide and morphine-6-glucuronide was non-competitive for nortriptyline, and competitive or mixed for amitriptyline and clomipramine. Lubrol PX activated the morphine-UDPGT four to five times. The degree of activation of the enzyme(s) was unaltered in presence of the inhibiting drugs. The inhibition was also observed at a tricyclic antidepressant/morphine concentration ratio close to that achieved in plasma from patients treated with these drugs.

Antidepressive Agents, Tricyclic↗

The postsynaptic effects of antidepressant drugs in the rat anococcygeus muscle.

The effects of antidepressants of tricyclic (amitriptyline, nortriptyline, protriptyline, doxepin, imipramine, and desipramine) and atypical (maprotiline, nomifensine, tandamine, viloxazine, CGP 6085A, and YM-08054-1) structures on contractile responses to exogenously applied acetylcholine and (-) noradrenaline were studied in rat isolated anococcygeus muscle previously incubated with 6-hydroxydopamine. Atropine, amitriptyline, protriptyline, doxepin, imipramine, maprotiline and nortriptyline inhibited contractile responses to acetylcholine whereas desipramine, nomifensine, tandamine, viloxazine, CGP 6085A and YM 08054-1 did not. The contractile responses to (-)-noradrenaline were inhibited by low concentrations of tricyclic antidepressants and by higher concentrations of the atypical agents. These results illustrate that, in the preparation, the order of potency of antidepressants as muscarinic and as postsynaptic alpha-adrenoceptor antagonists is similar. The ability of tricyclic, but not atypical agents, to increase the concentration of noradrenaline bound to postsynaptic alpha-adrenoceptors may be severely limited by the antagonistic effect these agents have at this receptor.

Acetylcholine↗

New evidence of serotonin-deficient depressions.

In 30 patients suffering from vital depression (the syndrome of endogenous depression) a negative correlation was found between the pre-therapeutic post-probenecid CSF 5-HIAA response and the therapeutic response to clomipramine (Anafranil). Clomipramine is a tricyclic antidepressant with a strong potentiating effect on central 5-HT. The following conclusion was drawn: if the cenral 5-HT turnover is diminished in depressions, then correction of this biochemical disturbance leads to alleviation of depressive symptoms. This finding is considered to support the concept of '5-HT-deficient depression'. Five of the 8 clomipramine-resistant patients showed a favourable response to nortriptyline, a NA-potentiating anti-depressant. The pre-therapeutic CSF MHPG concentration in these patients was not related to the therapeutic efficacy of nortriptyline. So, the assumption that these patients have been NA-deficient was not confirmed. However, renal MHPG excretion was not measured and possibly this variable correlates better with cerebral NA metabilism than MHPG in lumbar CSF which is of mainly spinal origin.

Adult↗

Antidepressant treatment during breast-feeding.

OBJECTIVE: The primary purpose of this article is to review critically the literature about use of antidepressants during lactation. Strategies for the clinical management of depressed breast-feeding mothers are also suggested. METHOD: The authors conducted a computerized search of MEDLINE for articles. The review includes studies in which serum levels of drugs were obtained from nursing infants. RESULTS: Fifteen published reports were located that provided information for the following nine antidepressants: amitriptyline, nortriptyline, desipramine, clomipramine, doxepin, dothiepin, fluoxetine, sertraline, and bupropion. CONCLUSIONS: Amitriptyline, nortriptyline, desipramine, clomipramine, dothiepin, and sertraline were not found in quantifiable amounts in nurslings, and no adverse effects were reported. Therefore, these are the drugs of choice for breast-feeding women. Adverse effects were described in some young infants whose mothers had been treated with doxepin or fluoxetine during breast-feeding. The collective serum level data suggest that infants older than 10 weeks are at low risk for adverse effects of tricyclics, and there is no evidence of accumulation. Research needs include an expanded database of mother-baby serum levels, behavioral assessments of infants during nursing, and longitudinal developmental evaluation of nurslings. Prescription of an antidepressant for a breast-feeding woman is a case-specific risk-benefit decision.

Age Factors↗

Pooled analysis of antidepressant levels in lactating mothers, breast milk, and nursing infants.

OBJECTIVE: The available data on antidepressant levels in nursing infants were analyzed in order to calculate average infant drug levels and determine what factors influence plasma drug levels in breast-feeding infants of mothers treated with antidepressants. METHOD: Electronic searches of MEDLINE, PreMEDLINE, Current Contents, Biological Abstracts, and PsycINFO from 1966 through July 2002 followed by bibliographic searches identified 67 relevant studies (two unpublished). By consensus the authors identified 57 studies of maternal plasma, breast milk, and/or infant plasma antidepressant levels from nursing mother-infant pairs, measured by liquid chromatography. RESULTS: Infants with recent prenatal exposure and symptomatic infants included in case reports were analyzed separately. Infant plasma levels were standardized against the average maternal level for each drug. The average infant-maternal plasma ratio was calculated for each drug, and correlations of infant plasma level to maternal dose, maternal plasma level, and breast milk level were calculated. Nortriptyline, paroxetine, and sertraline usually produce undetectable infant levels. Of drugs currently used, fluoxetine produces the highest proportion (22%) of infant levels that are elevated above 10% of the average maternal level. Based on smaller numbers, the data on citalopram indicate that it produces elevated levels in 17% of infants. The milk-to-plasma ratios for 11 antidepressants had a statistically significant negative association with the percentage of the drug bound to protein. CONCLUSIONS: Nortriptyline, paroxetine, and sertraline may be preferred choices in breast-feeding women. Minimizing the maternal dose may be helpful with citalopram. Current data do not support monitoring breast milk levels in individual patients. Future researchers should report maternal, breast milk, and infant antidepressant levels along with other appropriate variables.

Antidepressive Agents↗

Misoprostol for tinnitus.

Practitioners should realize that further study of misoprostol in larger patient populations must be undertaken to determine its efficacy and safety in the treatment of tinnitus. Previous approaches to treating tinnitus have included carbamazepine, phenytoin, lidocaine, tocainide, flecainide acetate, alprazolam, and nortriptyline. Studies using lidocaine, nortriptyline, or alprazolam have shown encouraging results. The relative contribution of misoprostol remains to be seen; however, it may offer a new treatment option to patients who have experienced adverse effects or have contraindications to the pharmacologic agents currently available.

Clinical Trials as Topic↗

Psychotherapy alone and combined with pharmacotherapy in the treatment of depression.

BACKGROUND: The relative efficacy of psychotherapy and combined therapy in the treatment of depression is still a matter of debate. AIMS: To investigate whether combined therapy has advantages over psychotherapy alone. METHOD: A 6-month randomised clinical trial compared Short Psychodynamic Supportive Psychotherapy (n=106) with combined therapy (n=85) in ambulatory patients with mild or moderate major depressive disorder diagnosed using DSM-IV criteria. Antidepressants were prescribed according to a protocol providing four successive steps in case of intolerance or inefficacy: venlafaxine, selective serotonin reuptake inhibitor, nortriptyline and nortriptyline plus lithium. Efficacy was assessed using the 17-item Hamilton Rating Scale for Depression, the Clinical Global Impression of Severity and of Improvement, and the depression sub-scale of the Symptom Checklist. RESULTS: The advantages of combining antidepressants with psychotherapy were equivocal. Neither the treating clinicians nor the independent observers were able to ascertain them, but the patients experienced them clearly. CONCLUSIONS: The advantages of combining antidepressants with psychotherapy are equivocal.

Adult↗

Avoidance enhancement and discriminative response control by anxiolytics with drugs acting on the GABA system.

Two types of conditioned behaviors were investigated for the purpose of evaluating anxiolytic drugs. A conditioning procedure used was an active avoidance in poorly-performing mice. Chlordiazepoxide, diazepam, chlorazepate and meprobamate increased the avoidance rate, while chlorpromazine, haloperidol and nortriptyline did not produce such an effect. The effect of diazepam was potentiated by gamma-aminobutyric acid (GABA) and aminoxyacetic acid (AOAA) and antagonized by picrotoxin and thiosemicarbazide, but was influenced little by spiroperidol, alpha-methyltyrosine, phenoxybenzamine and levallorphan. In addition, the effect of other anxiolytics was potentiated by AOAA and antagonized by picrotoxin. Biperiden, methamphetamine, caffeine and morphine also induced an avoidance enhancement, which was not influenced by AOAA. A drug discrimination experiment was also performed using a milk-reinforced two-lever operant method. In the rats trained to discriminate phenobarbital from saline, diazepam produced a dose-related phenobarbital-lever selection, which was potentiated by AOAA and antagonized by picrotoxin. Chlordiazepoxide, chlorazepate and meprobamate also elicited responses on the phenobarbital-lever. On the other hand, haloperidol, nortriptyline, biperiden, methamphetamine, caffeine and morphine produced a saline-lever selection, at the doses tested. These results suggest that, among several drugs tested, the avoidance enhancement and discriminative response control by anxiolytics may be closely linked with the GABA system.

Aminooxyacetic Acid↗

Psychotropic drugs and the ECG: focus on the QTc interval.

The QT interval measuring depolarisation and repolarisation has, when lengthened, been implicated as a risk factor for the development of torsades de pointes and sudden death, particularly in patients predisposed to these complications due to cardiovascular impairment. Since some of the medications used in psychiatry have been implicated, an extensive review of available literature was made of the major classes, including antipsychotics, antidepressants, lithium, anticonvulsants and benzodiazepines. Further, where no publications were found on a particular medication, the pharmaceutical firms responsible for these items were contacted concerning possibly unpublished data. Results of the survey indicate that there may be difficulty in one of three situations: immediate (in the first minutes to hours after oral or parenteral administration), short-term use of 4 - 12 weeks or long-term use of 6 months. Based on this approach, the greatest concern is directed at the immediate application of haloperidol, droperidol, pimozide and trazodone, the short-term use of thioridazine, pimozide, sertindole, nortriptyline, clomipramine, doxepin and the long-term use of clozapine, olanzapine and carbamazepine. It is of interest that a reduction in QTc is reported with aripiprazole. Among the antidepressants, the tertiary tricyclic antidepressants (imipramine, amitriptyline and doxepin) appear to have a more general impact, while the secondary tricyclic antidepressants (nortriptyline, desipramine) may impact more on children and the elderly. Among other antidepressants, the only reports of torsades de pointes appeared to occur with mirtazapine. It was also of interest to find data showing no effect or reductions in QTc produced by sertraline, citalopram, paroxetine and bupropion in multiple studies. Effects of medications on other heart parameters are also briefly reviewed. In particular, the safety of sertraline in post-MI patients and of bupropion in heart disease patients is highlighted. Little information was available on other classes of medications used in psychiatric disorders. What is available concerning lithium, the anticonvulsants and the benzodiazepines indicates little effect on the QTc, although there may be effects on other cardiovascular parameters.

Adolescent↗

Fluoxetine: a review of its therapeutic potential in the treatment of depression associated with physical illness.

UNLABELLED: Fluoxetine is a potent and selective inhibitor of neuronal serotonin (5-hydroxytryptamine) reuptake. Fluoxetine reduces food, energy and carbohydrate intake and increases resting energy expenditure, which may account for the moderate and transient bodyweight loss observed with its use. Glucose tolerance and/or hypoglycaemia in patients with type 2 diabetes mellitus improve with fluoxetine therapy. The ability of fluoxetine to inhibit cytochrome P450 (CYP) isoenzymes (CYP2D6, CYP2C and CYP3A4), is potentially important for patients with physical illness who may be taking multiple concomitant medications. Fluoxetine was more effective than placebo in 2 double-blind, randomised trials, and according to limited data appears to be equally effective compared with other SSRIs and tricyclic antidepressants (TCAs), in the treatment of depression in patients with HIV/AIDS. The efficacy of fluoxetine is also superior to that of placebo in the treatment of depression in patients with diabetes mellitus and stroke as shown in double-blind randomised trials, although its efficacy relative to that of nortriptyline in stroke is uncertain. Fluoxetine had similar efficacy to that of desipramine in patients with cancer, with improved Hamilton Depression Rating Scale and quality-of-life scores from baseline; however, the drug was not more effective than placebo in a double-blind randomised trial. Medically healthy individuals tolerate fluoxetine well. Like other SSRIs, fluoxetine lacks the anticholinergic, cardiovascular, sedative and weight-increasing properties of TCAs, and is safer in overdose than TCAs and monoamine oxidase inhibitors. Rates of sexual dysfunction and suicidal ideation with fluoxetine appear similar to those seen with other SSRIs. CONCLUSION: Fluoxetine has shown superior efficacy compared with placebo in the treatment of depression in patients with HIV/AIDS, diabetes mellitus or stroke; however, it has not significantly improved depressive symptoms versus placebo in patients with cancer. The efficacy of fluoxetine appears similar to that of desipramine in patients with stroke, cancer or HIV, and is similar to that of sertraline or paroxetine in patients with HIV/AIDS; comparisons with nortriptyline give equivocal results. The potential for drug interactions with fluoxetine use should be carefully considered because most patients with comorbid physical illness will be receiving multiple comedications. Although fluoxetine has proved effective as an antidepressant in this population in several clinical trials, its drug interaction profile and long half-life are a potential limitation, and these properties should be carefully considered in relation to the status of each patient.

Acquired Immunodeficiency Syndrome↗

Evaluation of the Abbott ADx total serum tricyclic immunoassay.

The ADx total serum tricyclic antidepressant (TCA) fluorescence polarization immunoassay (Abbott Diagnostics) for the semi-quantitation of imipramine or amitriptyline and their respective N-demethylated metabolites in cases of TCA overdose was evaluated. The assay is linear from 75-1000 ng/mL total TCA in serum, and flaggs as "HI" all results exceeding 300 ng/mL. The within and between run precision of the assay for patient serum containing imipramine or amitriptyline and their metabolites gave CV's of less than 5.5% and 8.9%, respectively. A good correlation between the results of patient serum containing imipramine and desipramine simultaneously analyzed by ADx and gas liquid chromatography (GC) was observed, r2 = 0.964, n = 32. Results of patient serum containing amitriptyline and nortriptyline or doxepin and desmethyldoxepin analyzed by ADx and GC or GC-mass spectrometry were not well correlated; r2 = 0.738, n = 44 and r2 = 0.695, n = 21, respectively. The assay consistently flagged as "HI" serum with total imipramine and desipramine concentrations above 300 ng/mL by GC, and serum with greater than 360 ng/mL of amitriptyline and nortriptyline by GC/MS. No significant cross-reactivity was observed for drugs other than the TCA.

Antidepressive Agents, Tricyclic↗

Blockade of amine depletion by nisoxetine in comparison to other uptake inhibitors.

Nisoxetine, 3-(o-methoxyphenoxy)-3-phenyl-N-methyl-propyl-amine, is a new inhibitor of norepinephrine uptake. Nisoxetine antagonized 6-hydroxydopamine-induced depletion of norepinephrine in mouse heart with an ED50 of 0.9 mg/kg but had no effect on p-chloroamphetamine-induced depletion of serotonin in mouse brain at doses up to 32 mg/kg. Using the antagonism of these depleting agents to estimate inhibition of uptake into noradrenergic and serotoninergic neurons, we compared nisoxetine to several known amine uptake inhibitors. The order of effectiveness in antagonizing 6-hydroxydopamine action was protriptyline greater than desmethylimipramine greater than EXP 561 greater than nisoxetine greater than nortriptyline greater than chlorpheniramine greater than desmethylchlorimipramine greater than imipramine greater than doxepin greater than amitriptyline greater than chlorimipramine, with fluoxetine and its N-demethylated metabolite (103947) having no effect. In blocking p-chloroamphetamine, the order of effectiveness was EXP 561 greater than fluoxetine greater than 103947 greater than chlorpheniramine greater than chlorimipramine, with desmethylchlorimipramine, protriptyline, and nortriptyline having marginal effects and nisoxetine and the other drugs no effect at the highest dose tested, 32 mg/kg. Nisoxetine is thus one of the more potent and specific inhibitors of norepinephrine uptake, differing remarkably from fluoxetine to which it is related structurally.

Amines↗

Drug-facilitated sexual assault involving gamma-hydroxybutyric acid.

The first case involving an alleged sexual assault linked to the use of gamma-hydroxybutyric acid (GHB) in Oklahoma is reported. A-48-year-old Caucasian woman taking amitriptyline was known to have voluntarily ingested a sports drink containing a relaxing health product. She purportedly experienced unconsciousness that persisted for approximately 4 h. The toxicological testing on urine identified GHB, amitriptyline, and nortriptyline using a capillary Hewlett-Packard 6890 gas chromatograph coupled to a Hewlett-Packard 5973 mass selective detector (MSD). The GHB concentration in urine was 26.9 microg/mL. Urine concentrations of amitriptyline and nortriptyline were not determined. The analytical method used for identifying and quantitating GHB can be applied to matters of forensic interests.

Adult↗