[Effect of thymoleptics on hemodynamic indicators and prediction of the effectiveness of the treatment of endogenous depression]

In 92 patients (22 females and 70 males) with unipolar affective disorder hemodynamic studies using a radiocardiographic method were performed during treatment of a depressed phase of illness with amitriptyline or doxepin or mianserin. Frequent presentation of hemodynamic disturbances (increased heart rate and increased blood pressure) in the course of endogenous depression was noticed. Thymoleptic treatment causes the disturbances to alter in a statistically significant manner which allows to predict the final treatment outcome. Total Peripheral Resistance Index (TPRI) reveals the highest prognostic potential.

Is there a role for nonsedating antihistamines in motion sickness? Fallout from space research may soon benefit your patients

The rotating chair test, a novel research technique for simulating motion sickness, is used to study the effect of nonsedating oral antihistamines in preventing or forestalling motion sickness. After receiving terfenadine, astemizole, doxepin, or placebo, four groups of male volunteers were rotated at accelerating speed, and they made head movements out of the axis of rotation until they perceived that vomiting would occur if additional head movements were made. Those pretreated with doxepin or terfenadine experienced a statistically significant prophylactic effect, as measured by increased tolerance to Coriolis stimulation. This suggests that selective peripheral H1 antihistamine action may protect against motion sickness.

Doxepin therapy for postprandial symptomatic hypoglycaemic patients: neurochemical, hormonal and metabolic disturbances

1. Three oral glucose tolerance tests were performed in each of 32 symptomatic postprandial hypoglycaemic patients (before placebo, before doxepin therapy and after doxepin therapy). Plasma neurotransmitters were determined in parallel with assays of plasma insulin and glucose levels. 2. Three different types of patients were distinguished. Type I showed a low noradrenaline/adrenaline ratio, high dopamine levels and low platelet 5-hydroxytryptamine (serotonin) levels during basal periods. After a glucose load, late peaks of dopamine and free 5-hydroxytryptamine, which coincided with the symptoms but not with the nadir of plasma glucose, were observed. Type II showed a low basal plasma noradrenaline/adrenaline ratio. After a glucose load, progressive increases in adrenaline and decreases in glucose were seen. Adrenergic symptoms coincided with the nadir of glucose. Although type III patients showed hyperinsulinaemia after a glucose load similar to the other types of patient, they did not show hyperglycaemia, but rather exhibited a sustained and progressive reduction in plasma glucose. These patients were characterized by a high basal plasma noradrenaline/adrenaline ratio, high basal plasma levels of 4-hydroxy-3-methoxyphenylethyleneglycol and high basal levels of platelet 5-hydroxytryptamine, all of which increased after a glucose load. Systolic and diastolic blood pressure decreases paralleled reductions in heart rate and glucose. The nadir of plasma glucose occurred simultaneously with the appearance of symptoms (weakness, heartburn, oppressive chest pain, tension headache, abdominal cramps, dizziness, etc.). Therapy with doxepin led to disappearance of the symptoms within 3-4 weeks. Normalization of all other disordered variables (cardiovascular, metabolic and neurochemical, and the clonidine test) paralleled the disappearance of the symptoms. 3. Symptoms varied in the three types of patients and we conclude that they are related to hypoglycaemia-induced disorders of plasma neurotransmitters, rather than to hypoglycaemia per se. We postulate that an uncoping stress situation (type I and II patients) and depression (type III patients) underlie the physiopathological mechanisms.

Effects of doxepin on withdrawal symptoms in smoking cessation

In a double-blind study, 15 cigarette smokers self-monitored 10 withdrawal symptoms. For the first 21 days (baseline), subjects received doxepin hydrochloride, up to 150 mg/day, or inert medication while continuing to smoke. On day 22, they were instructed to stop smoking; medication was continued. Withdrawal symptoms on the first 28 days of treatment (baseline and 7 days of attempted cessation) were analyzed. During cessation, subjects taking doxepin reported significantly less craving for cigarettes. Results from this study and others suggest that antidepressants may attenuate the severity of symptoms during withdrawal from addictive substances.

Effects of antidepressants on human performance: a review

Despite widespread use of antidepressants, major gaps remain in our knowledge of the effects of antidepressants on human performance. While most single-dose studies with normal subjects have suggested that the more sedating tricyclic antidepressants tend to produce impairment, the effects of antidepressant treatment in clinical populations have been less thoroughly examined, with both drug-induced impairment and improvement reported. This review suggests that factors such as age, diagnosis, drug plasma concentration, and length of treatment need to be explored to establish the effects of antidepressants on performance in clinical populations.

Mechanism of action of doxepin in the treatment of chronic urticaria

The present study examined 15 patients previously resistant to conventional antihistamines, in which doxepin at doses in the range of 50-75 mg/day was shown to be effective in treatment of chronic urticaria and without significant adverse side effects. However, some controversy remains about its mechanism of action in this particular disease. The aim of the present study was to examine the muscarinic, H1 and H2 blocking activity of doxepin. The following methods were used: a) gastric acid hypersecretion induced by histamine and carbachol in the pylorus-ligated rat preparation; b) contractile dose-response curves to histamine and carbachol in the guinea pig ileum; c) dimaprit-stimulated guinea pig atrium in vitro. pA2 values were determined for atropine, mepyramine, cimetidine and doxepin. As regards histamine, doxepin (50 mg/kg, po) increased gastric pH and decreased secretion volume, gastric acid concentration and total acid output; with carbachol, doxepin weakly antagonized those values. In the ileum, doxepin competitively antagonized carbachol (pA2 = 7.08) and histamine (pA2 = 9.72); pA2 values for atropine and mepyramine against carbachol and histamine were 9.11 and 8.82, respectively. In the atria, the dose-response curve to dimaprit was also competitively displaced by cimetidine (pA2 = 6.69) and doxepin (pA2 = 6.00). Doxepin displayed a very high affinity for H1 histamine receptor, being 8-fold more potent than mepyramine. Doxepin showed significant H2 blocking activity which was 5 times less potent than that of cimetidine. Doxepin competitively antagonized carbachol in the guinea pig ileum, and was 107 times less potent than atropine. The combined H1, H2 and muscarinic blocking activities of doxepin may contribute towards explaining its clinical efficacy in the treatment of chronic urticaria.

Cis- and trans-isomers of doxepin and desmethyldoxepin in the plasma of depressed patients treated with doxepin

Plasma levels of doxepin and desmethyldoxepin were measured in split samples of 20 depressed patients treated with doxepin by using a conventional extraction and gas chromatography method on a packed column (method 1) and derivation of secondary amine and gas chromatography on a capillary column, allowing the separation and simultaneous quantitation of the cis- and trans-isomers of the two compounds (method 2). We have found that significantly higher levels of desmethyldoxepin and of total drug are detected in plasma when the two isomers are separated and measured by method 2. We concluded that the plasma levels of doxepin reported in most previous studies were underestimated since the cis- and trans-isomers were not separated and included in the total drug concentration. Because the activity of the two isomers is different and their proportion varies in individual patients, we suggest that in future studies correlating plasma levels and the clinical effects of doxepin, both the cis- and the trans-isomers of doxepin and desmethyldoxepin be determined.

[Intravenous versus oral treatment of endogenously depressed patients with doxepin--a double-blind study with plasma level determination]

A double-blind study was conducted involving 45 "therapy-resistant" endogenous depressive inpatients who were treated with Doxepin intravenously or orally. After a period of 3 weeks there was no significant difference in the clinical ratings (HRSD, SDS). In the parenteral treatment group, however there was a statistically significant quicker onset of action (day 3). Compared to oral application higher Doxepin plasma concentrations during day 1 to 6 could be obtained by drip-infusion in spite of lower dosage.

Doxepin in the treatment of female detrusor overactivity: a randomized double-blind crossover study

A total of 19 women with detrusor overactivity and associated symptoms completed a double-blind placebo-controlled crossover study of doxepin. All patients had previously failed to respond to conventional pharmacotherapy. Doxepin was given at bedtime in a single 50 mg. dose for the first 2 weeks and, if needed, the dose was increased with 25 mg. in the morning for the last week of the 3-week treatment period, which was followed by 2 weeks of washout before crossover. The preference for doxepin to placebo was statistically significant (p less than 0.01). Doxepin caused a significant decrease in the nighttime micturition frequency and the nighttime incontinence episodes (p less than 0.05). Urine loss at the standardized 1-hour pad weighing test decreased significantly during treatment with doxepin although statistical significance (p equals 0.07) was not obtained. Cystometric parameters (first sensation and maximum cystometric capacity) improved significantly during treatment with doxepin (p less than 0.06 and less than 0.04, respectively). Side effects were frequent but mild. Suggestions for use of this tricyclic antidepressant in women with detrusor overactivity and possible mechanisms of action are discussed.

Depression-dependent exacerbation of tardive dyskinesia

A middle-aged woman with a recurrent depressive illness showed worsening of her tardive dyskinesia during the depressive phases, with improvement on remission.

Tricyclic antidepressants for medically ill geriatric patients

The author reviews available data on tricyclic antidepressant (TCA) use in medically ill geriatric patients and data from controlled trials performed with physically healthy but depressed geriatric patients. Although these data point to the conclusion that medical illness appears to limit the use of TCAs in elderly patients, such agents as nortriptyline, desipramine, and doxepin can be used effectively. Guidelines are suggested to assist the clinician when confronted with this often complex and challenging patient population.

Doxepin as an adjunct to smoking cessation: a double-blind pilot study

In a double-blind study, 19 adults received bedtime doses of either 150 mg of doxepin hydrochloride (N = 9) or placebo (N = 10). After 3 weeks the subjects were instructed to stop smoking and continue taking medication for 4 additional weeks. Cessation was reported by all nine doxepin subjects 1 week after cessation and by seven doxepin subjects 9 weeks after cessation. One placebo subject reported cessation. Cotinine assays generally confirmed cessation but were subject to interpretation. Doxepin assays suggested that the precessation level was associated with cessation. Further studies with larger samples and extended follow-up are needed to determine the reliability of these results.

Sodium lactate infusions after treatment with tricyclic antidepressants: behavioral and physiological findings

Fourteen patients with panic disorder were infused with sodium lactate both before and after treatment with tricyclic antidepressants. All patients had panic attacks before treatment, and only five after treatment. There was a significant decrease in measures of anxiety prior to and during infusions after treatment. The patients were able to tolerate more lactate during reinfusions. The comparison of reinfusion panickers and nonpanickers revealed that the reinfusion panickers had higher levels of anxiety, as measured by psychological symptoms on the Panic Description Scale, during both their pretreatment and posttreatment infusions. Tricyclic antidepressants appear to increase the threshold for lactate-induced panic attacks.

[Psychopathologic prediction of ambulatory doxepin response. A replication trial]

This study tries to replicate findings of a previous outpatient study, which revealed some clinical predictors of doxepine response in depressed patients. 314 depressed outpatients were treated by a total of 262 private practice psychiatrists for 6 weeks with 100 mg doxepine daily. The following findings of the previous study could be confirmed: 74% of the patients were therapy responders (score on the Hamilton Depression Scale after 6 weeks less than or equal to 8); unpredictability of diagnostic subtyping into endogenous and non-endogenous depression (clinically according to ICD-9 and operationally according to the Newcastle Scale); response-predictability of the personality assessment as not being deviant, defined according to the Newcastle Scale (no previous "nervous breakdowns", no previous neurotic symptoms, no severe social maladaptation); response-predictability of an improvement after 2 weeks over the initial Hamilton score of greater than or equal to 30%. The practical relevance of these three findings for outpatient therapy with antidepressive drugs is stressed.