| Pharmacoepidemiol
Drug Saf. 2005 May 10; PURPOSE: Three recent observational studies reported that the risk of
fatal overdose is greater with venlafaxine than SSRI use. It is not clear
whether patient factors could account for this finding. We evaluated whether
risk factors for suicide are more prevalent among patients prescribed
venlafaxine than patients prescribed fluoxetine or citalopram. METHODS:
Using data from the UK General Practice Research Database (GPRD), we identified
patients who were first prescribed any of the three drugs between January
1995 and April 2002. We ascertained risk factors for suicide documented
in the 1 year before that first prescription. Separate analyses compared
venlafaxine (N = 27 096) and fluoxetine (N = 134 996) cohorts, and venlafaxine
and citalopram (N = 52 035) cohorts. RESULTS: Previous suicidal behaviors
were documented for 1.0% of the venlafaxine cohort compared to 0.4% of
the fluoxetine cohort (OR 2.8, 95%CI: 2.4, 3.2) and 0.4% citalopram cohorts
(OR 2.4, 95%CI: 2.0, 2.9). 72.5% of venlafaxine patients had been prescribed
at least one other antidepressant compared to 27.6% of fluoxetine (OR
6.9, 95%CI: 6.7, 7.1) and 39.5% of citalopram (OR 4.0, 95%CI: 3.9, 4.2)
patients. Venlafaxine patients were also four to six times as likely to
have been previously hospitalized for depression. CONCLUSION: In the UK,
venlafaxine has been selectively prescribed to a patient population with
a higher burden of suicide risk factors than patients prescribed fluoxetine
and citalopram. Unless baseline population differences are accounted for,
observational studies that compare the risk of suicide in patients receiving
these agents may produce biased results. Copyright (c) 2005 John Wiley
& Sons, Ltd. Neuropsychobiology. 2005 May 4;51(4):173-176 Depressive symptoms are found at any stage of schizophrenia, and antidepressant
medication may be beneficial. Selective serotonin reuptake inhibitor antidepressants
have been considered safe in schizophrenia but in combination with clozapine,
that is widely used in chronic treatment-resistant schizophrenia, remarkable
pharmacokinetic interactions can occur causing an elevation in clozapine
plasma levels. To investigate this further, the plasma levels of clozapine
were measured in 11 schizophrenic male patients with depressive symptoms
who were administered both clozapine and venlafaxine. Low to moderate
doses of venlafaxine did not seem to have any significant effect on clozapine
plasma levels. Copyright (c) 2005 S. Karger AG, Basel. Headache. 2005 Feb;45(2):144-52. Objective.-To evaluate the efficacy and safety of venlafaxine in the prophylaxis of migraine. Background.-The efficacy of venlafaxine, which is selectively effective on the serotonergic and noradrenergic mechanisms, on various headaches and chronic pain syndromes has been demonstrated. To our knowledge, this is the first placebo-controlled, double-blind, randomized study of two different doses of venlafaxine for migraine treatment. Methods.-In this prospective study, 60 migraine patients without aura were randomly assigned to venlafaxine XR 75 mg, venlafaxine XR 150 mg, or placebo. The frequency of headache attacks, the severity and the duration of attacks, and analgesic use were monitored every 2 weeks for 2 months. Adverse events and patient satisfaction were also evaluated during these visits. At the end of the 2 months, global efficacy and tolerance were investigated. Results.-A significant difference was observed between the venlafaxine 150 mg and placebo groups in the number of headache attacks (P= .006). According to patient satisfaction comparisons, the active drug groups were significantly different when compared with placebo (P= .001 at visit 2 and visit 6). When the global efficacy was considered, 80% of patients in the 75-mg group and 88.2% of the patients in the 150-mg group evaluated treatment benefits as either good or very good. Conclusions.-Venlafaxine was more effective than placebo and is safe and well tolerated as migraine prophylaxis. (Headache 2005;45:144-152). Int J Androl. 2005 Feb;28(1):47-52. In this study, we aimed at evaluating the efficacy and safety of venlafaxine
extended release 75 mg, a serotonin and noradrenaline reuptake inhibitor,
in the treatment of patients with premature ejaculation. Thirty-one patients
with intravaginal ejaculation latency of less than 2 min received venlafaxine
XR (75 mg/day) or placebo during a 2-week period for each agent with a
washout period of 1 week between agents. Efficacy was assessed for each
agent with changes in ejaculation latency measured with a stopwatch and
sexual satisfaction scores of patients and partners. Side-effects, pre-
and post-treatment levels of biochemical and spermiogram parameters, follicle-stimulating
hormone (FSH), luteinizing hormone (LH), prolactin and total testosterone
were recorded for each agent. Statistical analysis was performed on 21
patients. After 2 weeks of treatment with placebo and venlafaxine, ejaculation
latency time was significantly increased from 60.1 +/- 39.1 to 126.9 +/-
98.3 sec and to 178.1 +/- 122.8 sec, respectively (p < 0.0001 for each
one). However, the difference between the two agents was insignificant
(p = 0.144). Venlafaxine and placebo increased sexual satisfaction scores
of both patients and partners similarly, no statistically significant
difference was found between them in this respect. The incidence of side-effects
with venlafaxine was indifferent than that of placebo (p > 0.1) except
nausea (p = 0.035). Both agents did not change the blood and spermiogram
parameters significantly, except FSH increases. Short-term use of venlafaxine
XR 75 mg has only a placebo effect on ejaculation latency and sexual satisfaction
scores, therefore, is not appropriate for the patients with premature
ejaculation. Further dose-time studies are required to draw final conclusions
on the inefficacy of this drug in premature ejaculation. Eur J Health Econ. 2005 Jan 29. This study used decision modelling to compare the cost-effectiveness of venlafaxine XL (Efexor XL) to that of diazepam to treat non-depressed patients suffering from generalised anxiety disorder (GAD), from the perspective of the United Kingdom's National Health Service (NHS). Starting treatment with venlafaxine XL instead of diazepam significantly increased the expected probability of being in remission by 83% at 6 months (from 16.8% to 30.7%), and the expected probability of relapsing at 6 months was decreased by 79% (from 16.9% to 3.5%). The expected 6-month NHS cost of using venlafaxine XL to treat GAD was estimated to be pound353 compared to pound311 with diazepam. Hence starting GAD treatment with venlafaxine XL (75 mg per day) instead of diazepam (5 mg three times per day) is clinically more effective and the cost-effective strategy for managing non-depressed patients suffering from GAD in the UK.
ABSTRACT Aims The two studies presented here were conducted to assess
the efficacy of paroxetine, pentoxifylline, riluzole, venlafaxine and
pramipexole as medications for the treatment of cocaine dependence. Design
A multi-arm, modified blinded, placebo-controlled design was used. Setting
The studies were conducted at the Boston VA Healthcare System and the
Boston University School of Medicine Medication Development Research Unit
(MDRU). Participants Participants met criteria for cocaine dependence
during a 2-week screening period. Intervention Following random assignment
to one of the treatment groups, subjects received active medication or
placebo for 8 weeks in combination with cognitive behavioral counseling.
In the first study the efficacy of the antidepressant paroxetine (20 mg
daily), the phosphodiesterase inhibitor pentoxifylline (1200 mg daily)
and the glutamate release inhibitor riluzole (100 mg daily) was assessed.
The antidepressant venlafaxine (150 mg daily) and the dopamine agonist
pramipexole (1.5 mg daily) were evaluated in the second study. Measurements
Urine benzoylecgonine (BE) concentrations, self-report of cocaine use
and global impression scores served as primary outcome measures. Secondary
measures included assessments of cocaine craving and psychiatric functioning.
Adverse events were monitored during the treatment period. Findings None
of the active medications produced greater reductions in urine BE concentrations
over the treatment period than did placebo. There were trends for BE levels
to become reduced in the pentoxifylline group during the first 4 weeks
of treatment and for Addiction Severity Index (ASI) drug composite scores
to be lower in the pentoxyfylline group at end-point compared to the placebo
group. Significant within-group reductions in reported cocaine use and
craving were found for all treatment groups, but none of the active medications
were superior to placebo on these measures. The accuracy of self-reported
cocaine use declined over the study period. Overall, the active medications
were well tolerated. Conclusions This study does not support the use of
paroxetine, pentoxifylline, riluzole, venlafaxine or pramipexole for the
treatment of cocaine dependence. However, these results need to be interpreted
with caution because of the small size and lack of homogeneity of the
experimental groups. J Geriatr Psychiatry Neurol. 2004 Dec;17(4):219-24. Treatment response and side effects of venlafaxine were evaluated in an open-label trial of elderly outpatients with dysthymic disorder (DD). Patients received flexible dose (up to 300 mg/d) venlafaxine (Effexor XR) for 12 weeks. Of 23 study patients, 18 completed the trial. Fourteen (60.9%) were responders in intent-to-treat analyses with the last observation carried forward, and 77.8% were responders in completer analyses. Nearly half the sample (47.8%) met criteria for remission. In the intent-to-treat sample, increased severity of depression at baseline was associated with superior response, and the presence of cardiovascular disease was associated with poorer response. Venlafaxine open-label treatment was associated with fairly high response rates and generally good tolerability in elderly patients with DD. These results indicate that in elderly patients with DD, placebo-controlled trials of a dual reuptake inhibitor such as venlafaxine would be needed to assess its efficacy or to compare its efficacy to that of other antidepressants. Int J Geriatr Psychiatry. 2004 Oct;19(10):989-94. OBJECTIVES: The atypical subtype in patients with major depressive disorder is characterized by mood reactivity, significant weight gain or increase in appetite, hypersomnia, leaden paralysis and a long-standing pattern of interpersonal rejection sensitivity. Though atypical depression is well documented in younger patients, little attention has been paid to the atypical subtype in samples of late-life depressed patients. This study reports the patient characteristics and treatment results of an eight-week open-label trial of venlafaxine in a sample of older depressed patients with atypical subtype. METHODS: Patients received fixed dosing schedule (up to 300 mg/day) of venlafaxine (Effexor XR) for 8 weeks. RESULTS: In this sample of 17 patients, the mean age was 65.6 years and 77% were female. Most strikingly, 53% of patients presented with late-onset atypical depression defined as first episode after the age of 50. Fifteen of the 17 patients (88%) completed the eight-week treatment trial. The mean score on the HRSD 24-item decreased from 22.2 +/- 5.1 at baseline to 11.8 +/- 8.9 (p<0.001), and the mean total atypical item score decreased from 6.2 +/- 1.6 to 2.8 +/- 2.0 (p < 0.001). Remission was defined as a final HRSD < or = 10 and a 50% reduction in baseline HRSD score. The intent-to-treat remission rate was 65% and the completer remission rate was 73%. CONCLUSIONS: In this sample of late-life patients with atypical depression venlafaxine treatment was reasonably effective and well tolerated. However, the effectiveness of venlafaxine in this study must be considered in the context that this was an open trial of antidepressant medication. Insufficient attention has been given to the atypical subtype in late-life depression. Whether late-onset atypical depression is significantly different from early-onset atypical depression, and whether late-onset patients with atypical depression are significantly different from late-onset patients with other depressive subtypes are questions of compelling interest. J Orofac Pain. 2004 Spring;18(2):131-7. AIMS: To study in a randomized placebo-controlled design the efficacy of the antidepressant venlafaxine, a serotonin and a weak noradrenaline reuptake inhibitor, in the treatment of atypical facial pain (AFP). METHODS: The study was a randomized, double-blind, crossover comparison of venlafaxine and a placebo. It consisted of 2 treatment periods, each of 4 weeks' duration, separated by a 2-week washout period. Thirty patients suffering from chronic pain who had been diagnosed with AFP after a thorough clinical examination were recruited. Pain intensity and pain relief were registered at 6 visits. Anxiety, depression, and adverse effects were recorded. Venous blood samples were collected at the end of each treatment period for the determination of serum levels of venlafaxine and its metabolites. RESULTS: Twenty patients completed the trial. Eight patients discontinued because of adverse effects and 2 patients were excluded because of noncompliance. Two patients completed the trial but were excluded from the analysis because they experienced no pain at the baseline visit. There was no significant difference in pain intensity reduction between the maximum tolerated dose of venlafaxine (75 mg in most cases) and the placebo. Pain relief was significantly greater with venlafaxine than with the placebo treatment. Significantly more escape medication was consumed during the placebo period compared with the venlafaxine period. No significant correlation was found between the serum concentration of the drug and the response to treatment. Anxiety and depression scores did not differ between venlafaxine and placebo treatment. Adverse effects were equally common during both treatments. CONCLUSION: Venlafaxine was only modestly effective in the treatment of AFP. J Psychopharmacol. 2004 Jun;18(2):200-4. High doses of antidepressants are often used for treatment-resistant depression. Venlafaxine, a dual serotonin and noradrenaline reuptake inhibitor, has been shown to have a tolerable side-effect profile in previous studies using doses of up to 375 mg/day. We investigated the tolerability of higher than currently recommended doses of venlafaxine using the UKU side-effect rating scale. Seventy outpatients fulfilling DSM-IV criteria for major depressive disorder were recruited into two demographically matched groups according to their daily dosage of venlafaxine: high dose n = 35 (> or = 375 mg/day, range 375-600 mg, average 437 mg/day) or standard dose n = 35 (< 375 mg/day, range 75-300 mg, average 195 mg/day. Clinical characteristics were noted and the UKU side-effect rating scale was administered to a subsample of patients. The most frequently reported complaints in both groups were increased fatigue (48%), concentration difficulties (48%), sleepiness/sedation (37%), failing memory (44.4%) and weight gain (29.6%). Apart from weight gain, the complaints were found to be experienced significantly more severely by the high-dose group. Six patients discontinued venlafaxine due to intolerable side-effects but only two of these patients were on a high dose. There was a tendency for mildly raised blood pressure in 10% of patients on an average dose of 342 mg/day. However, no difference between the two groups was found. This preliminary open study demonstrates that venlafaxine is tolerated at higher than British National Formulary recommended doses (i.e. up to 600 mg daily). However, increased frequency and severity of reported side-effects in the high-dose group are not associated with increased rates of discontinuation. Arch Gerontol Geriatr. 2004 May-Jun;38(3):271-80. Depression in the elderly is frequent but is often not recognized or treated as such. Few studies have assessed the effectiveness and tolerability of venlafaxine extended-release in patients over 60 years in primary care. This study aims to demonstrate the effectiveness and safety of venlafaxine extended-release in depressive disorders in this kind of population. Observational, multicenter and prospective study in an outpatient population over 60 years with depressive symptoms that needs pharmacological treatment and with a minimum score of 14 on the 17-items Hamilton rating scale for depression (HAM-D17). Effectiveness was assessed by HAM-D17. Physician's assessment of the patient's global status was also used and all the possible adverse effects were recorded. Venlafaxine extended-release was administered for 6 months at 75 mg per day dose, with the possibility of going up to 150 mg per day according to clinical criterion. Data of 1214 patients were obtained, with remission rates (HAM-D17 </= 7) in 70.2% of the patients and response rates (50% decrease in HAM-D17) of 83.2%. Global assessment of the patient's status significantly improved in each visit. After 6 months of treatment, 87.6% of the patients continued taking 75 mg per day of venlafaxine extended release. A total of 4.6% of the patients reported adverse events during the study. Venlafaxine extended-release is effective and safe for the treatment of depression in elderly patients managed by primary care physicians. Neuropsychobiology. 2004;50(1):57-64. This 8-week, randomised, double-blind study compared the efficacy and tolerability of escitalopram to that of venlafaxine XR in primary care patients with major depressive disorder. The efficacy of escitalopram (10- 20 mg; n = 148) was similar to venlafaxine XR (75- 150 mg; n = 145), based on mean change from baseline to week 8 in Montgomery and Asberg Depression Rating Scale total score. In ad hoc analyses, escitalopram-treated patients achieved sustained remission significantly faster than did venlafaxine-treated patients. More venlafaxine-treated patients had nausea, constipation, and increased sweating (p < 0.05). When treatment was completed after 8 weeks, significantly more venlafaxine-treated patients had discontinuation symptoms (p < 0.01). Thus escitalopram treatment was similar to venlafaxine treatment with respect to efficacy and was better tolerated by patients in primary care. Copyright 2004 S. Karger AG, Basel Pharmacotherapy. 2004 May;24(5):621-9. Major depressive disorder (MDD) and anxiety disorders such as generalized anxiety disorder (GAD) are often accompanied by chronic painful symptoms. Examples of such symptoms are backache, headache, gastrointestinal pain, and joint pain. In addition, pain generally not associated with major depression or an anxiety disorder, such as peripheral neuropathic pain (e.g., diabetic neuropathy and postherpetic neuralgia), cancer pain, and fibromyalgia, can be challenging for primary care providers to treat. Antidepressants that block reuptake of both serotonin and norepinephrine, such as the tricyclic antidepressants (e.g., amitriptyline), have been used to treat pain syndromes in patients with or without comorbid MDD or GAD. Venlafaxine, a serotonin and norepinephrine reuptake inhibitor, has been safe and effective in animal models, healthy human volunteers, and patients for treatment of various pain syndromes. The use of venlafaxine for treatment of pain associated with MDD or GAD, neuropathic pain, headache, fibromyalgia, and postmastectomy pain syndrome is reviewed. Currently, no antidepressants, including venlafaxine, are approved for the treatment of chronic pain syndromes. Additional randomized, controlled trials are necessary to fully elucidate the role of venlafaxine in the treatment of chronic pain. Psychosomatics. 2004 May-Jun;45(3):217-9. OBJECTIVE: This study attempted to determine if extended-release venlafaxine is safe for use in severely medically and surgically ill depressed patients. METHOD: The charts of 16 patients who were admitted to medical and surgical inpatient services and given extended-release venlafaxine were retrospectively evaluated for dose and duration of drug treatment, blood pressure changes, medication changes, and side effects. RESULTS: There was 50%-75% improvement in depressive symptoms, with a statistically insignificant mean elevation in blood pressure. CONCLUSIONS: Extended-release venlafaxine appears to be a safe and tolerable agent for the medical-surgical depressed inpatient. J Clin Psychiatry. 2004 Mar;65(3):328-36. BACKGROUND: Major depression is often chronic and recurrent, yet most long-term therapeutic trials are not adequately designed to assess antidepressant efficacy in recurrence prevention. Long-term efficacy and safety of prophylactic venlafaxine treatment were evaluated in outpatients with recurrent major depression. METHOD: Patients with a history of recurrent DSM-III-R major depression received open-label treatment with venlafaxine, 100 to 200 mg/day, for 6 months. Those who responded to treatment (Hamilton Rating Scale for Depression [HAM-D(21)] score < or = 12, day 56) and remained relapse-free (no more than 2 HAM-D(21) scores > 10 and no Clinical Global Impressions-Severity of Illness [CGI-S] score > or = 4, months 2-6) either continued taking venlafaxine, 100 to 200 mg/day, or were switched in a double-blind fashion to placebo for 12 months. The primary efficacy outcome was the number of patients experiencing a recurrence of major depression (CGI-S score > or = 4). The cumulative probability of recurrence was calculated using the Kaplan-Meier method of survival analysis. Data were collected from November 1992 through December 1995. RESULTS: Of the 235 patients who enrolled in the recurrence-prevention period, 225 (N = 109, venlafaxine; N = 116, placebo) provided efficacy data. Survival analysis determined a 22% cumulative probability of recurrence in venlafaxine-treated patients after 12 months compared with 55% for the placebo group (p <.001). More than twice as many placebo-treated patients (48%) as venlafaxine-treated patients (21%) discontinued treatment because of lack of efficacy (p <.001). CONCLUSION: Twelve-month maintenance venlafaxine treatment was significantly more efficacious than placebo in preventing major depression recurrence in patients who had been successfully treated with venlafaxine for 6 months. Actas Esp Psiquiatr. 2004 Mar-Apr;32(2):92-7. INTRODUCTION: The objective of this study is to investigate analgesic effectiveness and safety of venlafaxine extended release in chronic pain of any etiology. METHODS: Six month, observational, open study, carried out in two pain units. Initially, a daily dose of 75 mg of venlafaxine extended release was administered, increasing it to 150 mg, following clinical criteria. Treatment response was measured using the Visual Analogue Scale (VAS), rest and mobilization, Hospital Anxiety and Depression Scale (HAD) and Eastern Cooperative Oncology Group (ECOG) and an adverse event sheet to record adverse events occurring during the study. RESULTS: The study was carried out in a 50 patient sample with a mean age of 57.1 +/- 1.8 years, with chronic pain. A total of 85-90 % of the patients was maintained with a daily dose of 75 mg of venlafaxine extended release. This produced a gradual reduction of the VAS scores at rest (significant reduction of 5.2 +/- 1.1 to 2.7 +/- 1.5 points; (p<0.0005) and mobilization (significant reduction of 5.5 +/- 0.8 to 3.1 +- 1.6 points; p<0.0005). Pain relief increased progressively. Regarding physical activity measured by the ECOG scale, there was a reduction of the percentage of patients and increase of outpatients. Tolerability to venlafaxine was "excellent", "very good" or "good" for 72% of the patients. CONCLUSIONS: Extended release venlafaxine can be an effective and well-tolerated treatment in patients with chronic pain of any etiology, although it must be investigated in depth. Clin Gastroenterol Hepatol. 2003 May;1(3):211-8. BACKGROUND & AIMS: We have shown that venlafaxine-XR, a serotonin (5-HT) and norepinephrine reuptake inhibitor, enhanced gastric accommodation, whereas buspirone, a 5-HT(1A) receptor agonist, reduced postprandial symptoms after a fully satiating meal. Our aim was to compare the effects of venlafaxine, buspirone, and placebo on colonic sensorimotor functions in healthy adults. METHODS: In this randomized, double-blind, parallel-group, placebo-controlled trial of 60 healthy adults, we assessed the effects of oral venlafaxine, 150 mg; buspirone, 20 mg; and placebo on colonic sensorimotor functions. RESULTS: Venlafaxine increased colonic compliance relative to placebo; thus it decreased the intracolonic balloon pressure at half-maximum volume (P = 0.001) and altered the overall shape of the compliance curve, beta (P = 0.01). Venlafaxine also decreased fasting colonic tone (P = 0.02) and the tonic response to a meal (P = 0.003) compared with placebo; no differences in high amplitude phasic contractile events were observed. Pressure thresholds for first sensation (P = 0.1) and gas (P = 0.07) were not statistically significant with venlafaxine. The increase in pain scores per unit pressure during phasic distentions were affected by treatment (P = 0.02), with smallest changes on venlafaxine and highest on placebo. Buspirone did not significantly alter colonic compliance, tone, or sensation relative to placebo. CONCLUSIONS: Venlafaxine alters colonic compliance and tone, and tends to reduce sensation during colonic distention in healthy humans. These data support the need for further clinical and physiologic studies of venlafaxine in colonic disorders affecting motor and possibly sensory functions. |
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