Fluoxetine :: administration & dosage
Latest Paper:
New York University School of Medicine, New York, USA.
An evolution in antidepressant development in recent decades has resulted in agents with selective mechanisms of action. Although agents with a single selective mechanism of action were initially thought to have advantages over other antidepressants, investigators now recognize that combined-action antidepressants, such as venlafaxine and clomipramine, may offer additional advantages in terms of increased efficacy and improved tolerability. In fact, a growing body of clinical evidence suggests that compared with the single-action selective serotonin reuptake inhibitors, both venlafaxine and once-daily venlafaxine extended release (venlafaxine XR) have shown an enhanced efficacy that extends over the entire spectrum of major depression and anxiety disorders, an earlier onset of action, less tendency to cause weight gain, and a low risk for potentially serious drug-drug interactions with many commonly used medications. These advantages make venlafaxine XR an important option for the treatment of major depression and anxiety disorders.
Mesh-terms: Adult; Anti-Anxiety Agents :: administration & dosage; Antidepressive Agents, Second-Generation :: administration & dosage; Anxiety Disorders :: drug therapy; Delayed-Action Preparations; Depressive Disorder, Major :: drug therapy; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Therapy, Combination; Female; Fluoxetine :: administration & dosage; Humans; Male; Paroxetine :: administration & dosage; Psychiatric Status Rating Scales; Randomized Controlled Trials as Topic; Serotonin Uptake Inhibitors :: administration & dosage; Treatment Outcome;
Most cited papers:
BACKGROUND. Amitriptyline reduces the pain caused by peripheral-nerve disease, but treatment is often limited by side effects related to the drug's many pharmacologic actions. Selective agents might be safer and more effective. METHODS. We carried out two randomized, double-blind, crossover studies in patients with painful diabetic neuropathy, comparing amitriptyline with the relatively selective blocker of norepinephrine reuptake desipramine in 38 patients, and comparing the selective blocker of serotonin reuptake fluoxetine with placebo in 46 patients. Fifty-seven patients were randomly assigned to a study as well as to the order of treatment, permitting comparison among all three drugs and placebo as the first treatment. The patients rated the degree of pain present each day using verbal descriptors, and they also assessed the extent of pain relief globally at the end of each treatment period. RESULTS. After individual dose titration, the mean daily doses of the drugs were as follows: amitriptyline, 105 mg; desipramine, 111 mg; and fluoxetine, 40 mg. There was moderate or greater relief of pain in 28 of the 38 patients (74 percent) who received amitriptyline, 23 of the 38 patients (61 percent) who received desipramine, 22 of the 46 patients (48 percent) who received fluoxetine, and 19 of the 46 patients (41 percent) who received placebo. The differences in responses between amitriptyline and desipramine and between fluoxetine and placebo were not statistically significant, but both amitriptyline and desipramine were superior to placebo. Amitriptyline and desipramine were as effective in patients who were not depressed as in depressed patients, but fluoxetine was effective only in depressed patients. CONCLUSIONS. Desipramine relieves pain caused by diabetic neuropathy with efficacy similar to that of amitriptyline, offering an alternative for patients unable to tolerate the latter. Blockade of norepinephrine reuptake is likely to mediate the analgesic effect of these antidepressant drugs in diabetic neuropathy. Fluoxetine, which blocks serotonin uptake, is no more effective than placebo for the relief of pain.
Mesh-terms: Adult; Aged; Aged, 80 and over; Amitriptyline :: administration & dosage; Amitriptyline :: adverse effects; Amitriptyline :: therapeutic use; Analgesics :: therapeutic use; Depression :: complications; Desipramine :: administration & dosage; Desipramine :: adverse effects; Desipramine :: therapeutic use; Diabetic Neuropathies :: drug therapy; Double-Blind Method; Female; Fluoxetine :: administration & dosage; Fluoxetine :: adverse effects; Fluoxetine :: therapeutic use; Human; Infant, Newborn; Male; Middle Aged; Pain :: drug therapy;
Fluoxetine is a new antidepressant which enhances serotoninergic neurotransmission through potent and selective inhibition of neuronal reuptake of serotonin. Metabolism by N-desmethylation occurs in man yielding desmethylfluoxetine, which also inhibits serotonin reuptake. Both the parent compound and metabolite possess elimination half-lives of several days facilitating the maintenance of steady-state plasma concentrations during long term treatment. Fluoxetine has overall therapeutic efficacy comparable with imipramine, amitriptyline and doxepin in patients with unipolar depression treated for 5 to 6 weeks, although it may be less effective than tricyclic antidepressants in relieving sleep disorders in depressed patients. Geriatric patients also responded as well to fluoxetine as to doxepin. The symptomatic improvement in patients with unipolar depression during short term fluoxetine treatment has been satisfactorily maintained when therapy was extended for at least 6 months: the relapse rate was low and similar to that of imipramine. Preliminary data have shown that patients with bipolar depression gained similar therapeutic benefit from fluoxetine or imipramine. Other preliminary trials have indicated that fluoxetine may be useful in obsessive-compulsive disorders. Usual doses of fluoxetine cause significantly fewer anticholinergic-type side effects than tricyclic antidepressants. Nausea, nervousness and insomnia are the most frequently reported fluoxetine-related adverse effects, but these have usually not been severe. Therapeutic doses of fluoxetine do not affect cardiac conduction intervals in patients without pre-existing cardiovascular disease and fluoxetine has been relatively safe in the small number of patients who have taken overdoses. It has not been clearly established whether some types of depression may respond more readily to fluoxetine than other antidepressants, and its overall therapeutic efficacy has not been compared with other second generation antidepressants. Thus, with its different and perhaps improved side effect profile compared with older tricyclic antidepressants, fluoxetine offers properties that could be used to advantage in many patients with depression.
Mesh-terms: Animals; Cardiovascular System :: drug effects; Central Nervous System :: drug effects; Clinical Trials; Comparative Study; Depressive Disorder :: drug therapy; Drug Interactions; Endocrine Glands :: drug effects; Fluoxetine :: administration & dosage; Fluoxetine :: adverse effects; Fluoxetine :: metabolism; Fluoxetine :: pharmacology; Fluoxetine :: therapeutic use; Human; Kinetics; Neurotransmitters :: metabolism; Propylamines :: administration & dosage; Propylamines :: adverse effects; Propylamines :: metabolism; Propylamines :: pharmacology; Propylamines :: therapeutic use; Receptors, Neurotransmitter :: metabolism; Serotonin :: metabolism;
BACKGROUND: Major depression affects more than 5% of the population and is a serious health and economic problem. Antidepressants have a slow onset of action and are effective in less than two-thirds of patients. The biochemical effects of selective serotonin reuptake inhibitors may be limited by the negative feedback from serotonin autoreceptors. Pindolol is an antagonist of both serotonin autoreceptors and beta-adrenoceptors. We studied the effect of the addition of pindolol to fluoxetine antidepressant treatment. METHODS: Of 132 eligible patients with major depression, 111 were randomly assigned to treatment with fluoxetine (20 mg daily) and either placebo or pindolol (7.5 mg daily). Patients were assessed twice a week for the first 3 weeks of active treatment and then once a week until the end of the study (42 days). Hamilton and Montgomery-Asberg depression-rating scales were used to assess depression severity. FINDINGS: The proportion of patients who responded to treatment with fluoxetine and pindolol was greater than that with fluoxetine and placebo (41/55 [75%] vs 33/56 [59%],[90% CI 1.1-30.1], p = 0.04). The proportion of patients who achieved a sustained response was also greater in the fluoxetine and pindolol group than in the fluoxetine and placebo group (38/55 [69%] vs 27/56 [48%][5.9-35.9], p = 0.03). The number of days to reach a sustained response was lower in the fluoxetine and pindolol group than in the fluoxetine and placebo group (median 19 vs 29 days, p = 0.01), however, there was no difference in the time-to-onset of clinical improvement when stringent conditions were used (15 vs 18 days, p = 0.20). INTERPRETATION: The addition of pindolol to fluoxetine antidepressant treatment increases the effectiveness of fluoxetine therapy. Further work is needed to resolve whether the time to clinical improvement benefits from this combination and whether the increase in efficacy occurs with other antidepressants.
Mesh-terms: Adult; Antidepressive Agents, Second-Generation :: administration & dosage; Antidepressive Agents, Second-Generation :: therapeutic use; Depression :: drug therapy; Double-Blind Method; Drug Therapy, Combination; Female; Fluoxetine :: administration & dosage; Fluoxetine :: therapeutic use; Human; Male; Middle Aged; Pindolol :: administration & dosage; Pindolol :: therapeutic use; Psychiatric Status Rating Scales; Serotonin Uptake Inhibitors :: administration & dosage; Serotonin Uptake Inhibitors :: therapeutic use; Support, Non-U.S. Gov't; Time Factors; Treatment Outcome;
BACKGROUND AND PURPOSE: In animals, drugs that increase brain amine concentrations influence the rate and degree of recovery from cortical lesions. It is therefore conceivable that antidepressants may influence outcome after ischemic brain injury in humans. We evaluated the effects of the norepinephrine reuptake blocker maprotiline and the serotonin reuptake blocker fluoxetine on the motor/functional capacities of poststroke patients undergoing physical therapy. METHODS: Fifty-two severely disabled hemiplegic subjects were randomly assigned to three treatment groups; during 3 months of physical therapy, patients were treated with placebo, maprotiline (150 mg/d), or fluoxetine (20 mg/d). Before and at the end of the observation period, we assessed activities of daily living by the Barthel Index, degree of neurological deficit by a neurological scale for hemiplegic subjects, and depressive symptomatology by the Hamilton Depression Rating Scale. RESULTS: The diverse treatments ameliorated walking and activities of daily living capacities to different extents. The greatest improvements were observed in the fluoxetine-treated group and the lowest in the maprotiline-treated group. Furthermore, fluoxetine yielded a significantly larger number of patients with good recovery compared with maprotiline or placebo. These effects of the drugs were not related to their efficacy in treating depressive symptoms. CONCLUSIONS: Fluoxetine may facilitate or, alternatively, maprotiline may hinder recovery in poststroke patients undergoing rehabilitation. The effects of fluoxetine as an adjunct to physical therapy warrant further investigation, since treatment with fluoxetine may result in a better functional outcome from stroke than physical therapy alone.
Mesh-terms: Activities of Daily Living; Adrenergic Uptake Inhibitors :: administration & dosage; Adrenergic Uptake Inhibitors :: therapeutic use; Aged; Antidepressive Agents, Second-Generation :: administration & dosage; Antidepressive Agents, Second-Generation :: therapeutic use; Brain Ischemia :: complications; Brain Ischemia :: rehabilitation; Cerebrovascular Disorders :: complications; Cerebrovascular Disorders :: rehabilitation; Comparative Study; Depression :: psychology; Female; Fluoxetine :: administration & dosage; Fluoxetine :: therapeutic use; Hemiplegia :: etiology; Hemiplegia :: rehabilitation; Human; Male; Maprotiline :: administration & dosage; Maprotiline :: therapeutic use; Neurologic Examination; Physical Therapy Techniques; Placebos; Psychomotor Performance :: drug effects; Serotonin Uptake Inhibitors :: administration & dosage; Serotonin Uptake Inhibitors :: therapeutic use; Treatment Outcome; Walking;
S A Montgomery,
H Dufour,
S Brion,
J Gailledreau,
X Laqueille,
G Ferrey,
P Moron,
N Parant-Lucena,
L Singer,
J M Danion
Lilly Research Laboratories, Eli Lilly and Company, Department of Pediatrics, Methodist Hospital of Indiana, Indianapolis, USA.
Prospectively identified fluoxetine-exposed pregnancies were evaluated to determine whether fluoxetine, a serotonin reuptake inhibitor commonly used for the treatment of depression and obsessive-compulsive disorder, might be associated with neonatal complications after maternal fluoxetine exposure during the third trimester through delivery. The outcomes of all prospectively identified, spontaneously reported pregnancies with confirmed fluoxetine exposure during the third trimester through delivery were evaluated. Postnatal complications unrelated to malformations were reported in 15 of the 112 identified pregnancies (115 infants), but there was neither a consistent or recurring pattern nor a dose relationship. On the basis of this survey and comparison with reported rates from the National Hospital Discharge Survey, it is unlikely that maternal fluoxetine use during the third trimester results in significant postnatal complications.
Mesh-terms: Abnormalities, Drug-Induced :: etiology; Adult; Antidepressive Agents, Second-Generation :: administration & dosage; Antidepressive Agents, Second-Generation :: adverse effects; Depressive Disorder :: drug therapy; Dose-Response Relationship, Drug; Female; Fluoxetine :: administration & dosage; Fluoxetine :: adverse effects; Human; Infant, Newborn; Obsessive-Compulsive Disorder :: drug therapy; Pregnancy; Pregnancy Complications :: drug therapy; Pregnancy Outcome; Pregnancy Trimester, Third; Prenatal Exposure Delayed Effects; Prospective Studies; Risk Factors;
Irena Nulman,
Joanne Rovet,
Donna E Stewart,
Jacob Wolpin,
Pia Pace-Asciak,
Samar Shuhaiber,
Gideon Koren
Motherisk Program, Division of Pediatrics and Psychology and the Reseaarch Institute, The Hospital for Sick Children, Toronta, Ont. Canada.
OBJECTIVE: Previous work suggested that first-trimester exposure to tricyclic antidepressants or fluoxetine does not affect adversely child IQ and language development. However, many women need antidepressants throughout pregnancy to avoid morbidity and suicide attempts. Little is known about the fetal safety of tricyclic antidepressants and fluoxetine when taken throughout pregnancy. The goal of this study was to assess the effects of tricyclic antidepressants and fluoxetine used throughout gestation on child IQ, language, and behavior. METHOD: In a prospective study, mother-child pairs exposed throughout gestation to tricyclic antidepressants (N=46) or fluoxetine (N=40) and an unexposed, not depressed comparison group (N=36) were blindly assessed. The three groups were compared in terms of the children's IQ, language, behavior, and temperament between ages 15 and 71 months. The authors adjusted for independent variables such as duration and severity of maternal depression, duration of pharmacological treatment, number of depression episodes after delivery, maternal IQ, socioeconomic status, cigarette smoking, and alcohol use. RESULTS: Neither tricyclic antidepressants nor fluoxetine adversely affected the child's global IQ, language development, or behavior. IQ was significantly and negatively associated with duration of depression, whereas language was negatively associated with number of depression episodes after delivery. CONCLUSIONS: Exposure to tricyclic antidepressants or fluoxetine throughout gestation does not appear to adversely affect cognition, language development, or the temperament of preschool and early-school children. In contrast, mothers' depression is associated with less cognitive and language achievement by their children. When needed, adequate antidepressant therapy should be instituted and maintained during pregnancy and postpartum.
Mesh-terms: Antidepressive Agents :: administration & dosage; Antidepressive Agents :: adverse effects; Antidepressive Agents, Tricyclic :: administration & dosage; Antidepressive Agents, Tricyclic :: adverse effects; Child; Child Behavior :: drug effects; Child, Preschool; Depressive Disorder :: drug therapy; Depressive Disorder :: psychology; Female; Fluoxetine :: administration & dosage; Fluoxetine :: adverse effects; Follow-Up Studies; Gestational Age; Human; Infant; Infant, Newborn; Intelligence :: drug effects; Language Development; Male; Mother-Child Relations; Pregnancy; Pregnancy Complications :: drug therapy; Pregnancy Complications :: psychology; Prenatal Exposure Delayed Effects; Prospective Studies; Risk Factors; Support, Non-U.S. Gov't; Temperament :: drug effects;
The widely prescribed appetite suppressants D-fenfluramine and fluoxetine not only decrease feeding and body weight but also increase extracellular brain 5-HT. As central injection of 5-HT also decreases feeding, the drugs are often thought to require an increase of 5-HT at receptors in order to exert their hypophagic effect. However, much evidence now suggests that D-fenfluramine and its metabolite D-norfenfluramine can cause hypophagia by acting directly at unspecified 5-HT receptors and at 5-HT2C receptors, respectively, while fluoxetine may act independently of 5-HT receptors. These hypophagias may involve interference with the hyperphagic action of neuropeptide Y.
Mesh-terms: Appetite Depressants :: administration & dosage; Appetite Depressants :: pharmacology; Appetite Depressants :: therapeutic use; Body Weight :: drug effects; Brain :: drug effects; Brain :: metabolism; Dopamine Agonists :: metabolism; Dopamine Agonists :: pharmacology; Eating :: drug effects; Eating :: physiology; Female; Fenfluramine :: administration & dosage; Fenfluramine :: pharmacology; Fenfluramine :: therapeutic use; Fluoxetine :: administration & dosage; Fluoxetine :: pharmacology; Fluoxetine :: therapeutic use; Human; Male; Neuropeptide Y :: metabolism; Receptors, Serotonin :: drug effects; Receptors, Serotonin :: metabolism; Serotonin Agents :: administration & dosage; Serotonin Agents :: pharmacology; Serotonin Agents :: therapeutic use; Serotonin Uptake Inhibitors :: administration & dosage; Serotonin Uptake Inhibitors :: pharmacology; Serotonin Uptake Inhibitors :: therapeutic use;
BACKGROUND: A consistent finding in major depression has been a low plasma and red cell folate which has also been linked to poor response to antidepressants. The present investigation was designed to investigate whether the co-administration of folic acid would enhance the antidepressant action of fluoxetine. METHODS: 127 patients were randomly assigned to receive either 500 microg folic acid or an identical looking placebo in addition to 20 mg fluoxetine daily. All patients met the DSM-III-R criteria for major depression and had a baseline Hamilton Rating Scale (17 item version) score for depression of 20 or more. Baseline and 10-week estimations of plasma folate and homocysteine were carried out. RESULTS: Patients receiving folate showed a significant increase in plasma folate.This was less in men than in women. Plasma homocysteine was significantly decreased in women by 20.6%, but there was no significant change in men. Overall there was a significantly greater improvement in the fluoxetine plus folic acid group. This was confined to women where the mean Hamilton Rating Scale score on completion was 6.8 (S.D. 4. 1) in the fluoxetine plus folate group, as compared to 11.7 (S.D. 6. 7) in the fluoxetine plus placebo group (P<0.001).A percentage of 93. 9 of women, who received the folic acid supplement, showed a good response (>50% reduction in score) as compared to 61.1% of women who received placebo supplement (P<0.005). Eight (12.9%) patients in the fluoxetine plus folic acid group reported symptoms possibly or probably related to medication, whereas in the fluoxetine plus placebo group 19 (29.7%) patients reported such symptoms (P<0.05). LIMITATIONS AND CONCLUSIONS: Folic acid is a simple method of greatly improving the antidepressant action of fluoxetine and probably other antidepressants. Folic acid should be given in doses sufficient to decrease plasma homocysteine. Men require a higher dose of folic acid to achieve this than women, but more work is required to ascertain the optimum dose of folic acid.
Mesh-terms: Adult; Antidepressive Agents, Second-Generation :: administration & dosage; Antidepressive Agents, Second-Generation :: therapeutic use; Depression, Involutional :: blood; Depression, Involutional :: drug therapy; Double-Blind Method; Drug Therapy, Combination; Female; Fluoxetine :: administration & dosage; Fluoxetine :: therapeutic use; Folic Acid :: administration & dosage; Folic Acid :: blood; Folic Acid :: therapeutic use; Homocysteine :: blood; Human; Male; Middle Aged; Psychiatric Status Rating Scales; Sex Factors; Support, Non-U.S. Gov't; Treatment Outcome; Vitamin B 12 :: blood;
Per Svenningsson,
Eleni T Tzavara,
Jeffrey M Witkin,
Allen A Fienberg,
George G Nomikos,
Paul Greengard
Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY 10021, USA.
Fluoxetine (Prozac) is the most widely prescribed medication for the treatment of depression. Nevertheless, little is known about the molecular basis of its clinical efficacy, apart from the fact that fluoxetine increases the synaptic availability of serotonin. Here we show that, in vivo, fluoxetine, given either acutely or chronically, regulates the phosphorylation state of dopamine- and cAMP-regulated phosphoprotein of M(r) 32,000 (DARPP-32) at multiple sites in prefrontal cortex, hippocampus, and striatum. Acute administration of fluoxetine increases phosphorylation of DARPP-32 at the protein kinase A site, Thr-34, and at the casein kinase-1 site, Ser-137, and decreases phosphorylation at the cyclin-dependent kinase 5 site, Thr-75. Each of these changes contributes, through distinct signaling pathways, to increased inhibition of protein phosphatase-1, a major serine/threonine protein phosphatase in the brain. Fluoxetine also increases phosphorylation of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluR1 at Ser-831 and Ser-845. Both the fluoxetine-mediated increase in AMPA receptor phosphorylation at Ser-845-GluR1 and the beneficial responsiveness to fluoxetine in an animal test of antidepressant efficacy were strongly reduced in DARPP-32 knockout mice, indicating a critical role for this phosphoprotein in the antidepressant actions of fluoxetine. Mice chronically treated with fluoxetine had increased levels of DARPP-32 mRNA and protein and a decreased ability to increase phospho-Ser-137-DARPP-32 and phospho-Ser-831-GluR1. These chronic changes may be relevant to the delayed onset of therapeutic efficacy of fluoxetine.
Mesh-terms: Animals; Antidepressive Agents, Second-Generation :: administration & dosage; Antidepressive Agents, Second-Generation :: pharmacology; Cerebral Cortex :: drug effects; Cerebral Cortex :: metabolism; Corpus Striatum :: drug effects; Corpus Striatum :: metabolism; Depression :: drug therapy; Depression :: metabolism; Disease Models, Animal; Drug Administration Schedule; Fluoxetine :: administration & dosage; Fluoxetine :: pharmacology; Hippocampus :: drug effects; Hippocampus :: metabolism; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nerve Tissue Proteins :: genetics; Nerve Tissue Proteins :: metabolism; Phosphoproteins :: genetics; Phosphoproteins :: metabolism; Phosphorylation; RNA, Messenger :: metabolism; Receptors, AMPA :: metabolism; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. ; Serotonin :: metabolism; Serotonin Uptake Inhibitors :: administration & dosage; Serotonin Uptake Inhibitors :: pharmacology;
