Fluvoxamine

Fluvoxamine, commonly sold under the brand names Luvox and Faverin, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is primarily used to treat major depressive disorder and obsessive–compulsive disorder (OCD), but is also used to treat anxiety disorders such as panic disorder, social anxiety disorder, and post-traumatic stress disorder.
Fluvoxamine's side-effect profile is very similar to other SSRIs: constipation, gastrointestinal problems, headache, anxiety, irritation, sexual problems, dry mouth, sleep problems and a risk of suicide at the start of treatment by lifting the psychomotor inhibition, but these effects appear to be significantly weaker than with other SSRIs (except gastrointestinal side-effects). Although the many drug-drug interactions of fluvoxamine can be problematic (and may temper enthusiasm for its prescribing, advocation and usage to some), its tolerance-profile itself is actually superior in some respects to other SSRIs (particularly with respect to cardiovascular complications), despite its age. Compared to escitalopram and sertraline, indeed, fluvoxamine's gastrointestinal profile may be less intense, often being limited to nausea. Mosapride has demonstrated efficacy in treating fluvoxamine-induced nausea. It is also advised practice to divide total daily doses of fluvoxamine greater than 100 milligrams, with the higher fraction being taken at bedtime (e.g., 50 mg at the beginning of the waking day and 200 mg at bedtime). In any case, high starting daily doses of fluvoxamine rather than the recommended gradual titration (starting at 50 milligrams and gradually titrating, up to 300 if necessary) may predispose to nauseous discomfort.
It is on the World Health Organization's List of Essential Medicines.
Fluvoxamine is related to clovoxamine, a proposed SNRI which has been subject to a certain amount of investigative research but was never marketed.
Medical uses
In many countries (e.g., Australia, the UK, and Russia) it is commonly used for major depressive disorder. Fluvoxamine is also approved in the United States for obsessive–compulsive disorder (OCD), and social anxiety disorder. In Japan, it is also approved to treat OCD, social anxiety disorder and major depressive disorder. Fluvoxamine is indicated for children and adolescents with OCD. The NICE guidelines in the United Kingdom have, as-of 2005, authorised its use for obsessive-compulsive disorder in adults and adolescents of any age and children over the age of 7.
There is some evidence that fluvoxamine is effective for generalised social anxiety in adults, though the results may be compromised by having been funded by pharmaceutical companies.
There is tentative evidence that fluvoxamine may reduce the overall morbidity of COVID-19 and complications thereof.
Fluvoxamine is also effective for treating a range of anxiety disorders in children and adolescents, including generalized anxiety disorder, social anxiety disorder, panic disorder and separation anxiety disorder.
The drug works long-term, and retains its therapeutic efficacy for at least one year. It has also been found to possess some analgesic properties in line with other SSRIs and tricyclic antidepressants.
Adverse effects
Gastrointestinal side effects are more solely characteristic of those receiving treatment with fluvoxamine. Otherwise, fluvoxamine's side-effect profile is very similar to other SSRIs’.
Common (1–10% incidence) adverse effects
Abdominal pain
Agitation
Anxiety
Asthenia (weakness)
Constipation
Diarrhea
Dizziness
Dyspepsia (indigestion)
Headache
Hyperhidrosis (excess sweating)
Insomnia
Loss of appetite
Malaise
Nausea
Nervousness
Palpitations
Restlessness
Sexual dysfunction (including delayed ejaculation, erectile dysfunction, decreased libido, etc.)
Somnolence (drowsiness)
Tachycardia (high heart rate)
Tremor
Vomiting
Weight loss
Xerostomia (dry mouth)
Yawning
Uncommon (0.1–1% incidence) adverse effects
Arthralgia
Confusional state
Cutaneous hypersensitivity reactions (e.g. oedema [buildup of fluid in the tissues], rash, pruritus)
Extrapyramidal side effects (e.g. dystonia, parkinsonism, tremor, etc.)
Hallucination
Orthostatic hypotension
Rare (0.01–0.1% incidence) adverse effects
Abnormal hepatic (liver) function
Galactorrhoea (expulsion of breast milk unrelated to pregnancy or breastfeeding)
Mania
Photosensitivity (being abnormally sensitive to light)
Seizures
Unknown frequency adverse effects
Akathisia – a sense of inner restlessness that presents itself with the inability to stay still
Bed-wetting
Bone fractures
Dysgeusia
Ecchymoses
Glaucoma
Haemorrhage
Hyperprolactinaemia (elevated plasma prolactin levels leading to galactorrhoea, amenorrhoea [cessation of menstrual cycles], etc.)
Hyponatraemia
Mydriasis
Neuroleptic malignant syndrome – practically identical presentation to serotonin syndrome except with a more prolonged onset
Paraesthesia
Serotonin syndrome – a potentially fatal condition characterised by abrupt onset muscle rigidity, hyperthermia (elevated body temperature), rhabdomyolysis, mental status changes (e.g. coma, hallucinations, agitation), etc.
Suicidal ideation and behaviour
Syndrome of inappropriate antidiuretic hormone secretion
Urinary incontinence
Urinary retention
Violence towards others
Weight changes
Withdrawal symptoms
Interactions
Fluvoxamine inhibits the following cytochrome P450 enzymes:
CYP1A2 (strongly) which metabolizes agomelatine, amitriptyline, caffeine, clomipramine, clozapine, duloxetine, haloperidol, imipramine, phenacetin, tacrine, tamoxifen, theophylline, olanzapine, etc.
CYP3A4 (moderately) which metabolizes alprazolam, aripiprazole, clozapine, haloperidol, quetiapine, pimozide, ziprasidone, etc.
CYP2D6 (weakly) which metabolizes aripiprazole, chlorpromazine, clozapine, codeine, fluoxetine, haloperidol, olanzapine, oxycodone, paroxetine, perphenazine, pethidine, risperidone, sertraline, thioridazine, zuclopenthixol, etc.
CYP2C9 (moderately) which metabolizes nonsteroidal anti-inflammatory drugs, phenytoin, sulfonylureas, etc.
CYP2C19 (strongly) which metabolizes clonazepam, diazepam, phenytoin, etc.
CYP2B6 (weakly) which metabolizes bupropion, cyclophosphamide, sertraline, tamoxifen, valproate, etc.
By so doing, fluvoxamine can increase serum concentration of the substrates of these enzymes.
Fluvoxamine may also elevate plasma levels of olanzapine by approximately two times. Combined olanzapine and fluvoxamine, which may cause increased sedation, should be used cautiously and controlled clinically and by therapeutic drug monitoring to avoid olanzapine induced adverse effects and/or intoxication.
The plasma levels of oxidatively metabolized benzodiazepines (e.g., triazolam, midazolam, alprazolam and diazepam) are likely to be increased when co-administered with fluvoxamine. However, the clearance of benzodiazepines metabolized by glucuronidation (e.g., lorazepam; oxazepam, which is coincidentally a metabolite of diazepam; temazepam) are not affected by fluvoxamine and may be safely taken alongside fluvoxamine should concurrent treatment with a benzodiazepine be necessary. Additionally, it appears that benzodiazepines metabolized by nitro-reduction (clonazepam, nitrazepam) may also, in a somewhat similar vein, be unlikely to be affected by fluvoxamine. Concurrent use of diazepam (Valium) is generally inadvisable and should probably not be done.
Using fluvoxamine and alprazolam together can increase alprazolam plasma concentrations. If alprazolam is coadministered with fluvoxamine, the initial alprazolam dose should be reduced to the lowest effective dose.
Fluvoxamine and ramelteon coadministration is not indicated.
Fluvoxamine has been observed to increase serum concentrations of mirtazapine, which is mainly metabolized by CYP1A2, CYP2D6, and CYP3A4, by three- to four-fold in humans. Caution and adjustment of dosage as necessary are warranted when combining fluvoxamine and mirtazapine.
Fluvoxamine seriously affects the pharmacokinetics of tizanidine and increases the intensity and duration of its effects. Because of the potentially hazardous consequences, the concomitant use of tizanidine with fluvoxamine, or other potent inhibitors of CYP1A2, should be avoided.
When a beta-blocker is required, atenolol, pindolol and, possibly, metoprolol may be safer choices than propranolol, as the latter's metabolism is seriously, potentially dangerously, inhibited by fluvoxamine. Indeed, fluvoxamine may increase propranolol blood-levels by five-fold.
Anecdotally, more has been spoken about or (rightfully) assumed regarding the mutual compatibility of fluvoxamine and atenolol but the case may be similar with the other-two beta-blockers mentioned herein, also. This may be especially promising in the case of pindolol, when patients with obsessive-compulsive disorder especially, a principal indication for fluvoxamine, need a beta-blocker for hypertensive/cardiac reasons or may benefit from it for additional augmentation.
Clomipramine increases fluvoxamine levels and, conversely-likewise, fluvoxamine increases clomipramine levels (thereby its serotoninergic potential) and inhibits its metabolism to its strongly-noradrenergic metabolite, norclomipramine. Although the two drugs can certainly be prescribed and taken concurrently quite safely, and often are in the case of certain characteristic obsessional complexes, the inter-pharmacology between these two drugs is rather complex and caution is needed in doing this (often necessitating a lower dose of one or the other) to keep blood-levels of the two agents within acceptable levels and avoid serotonin-toxicity. Even-greater caution is needed when combining clomipramine with drugs which inhibit CYP2D6 (e.g., fluoxetine, paroxetine), if it has to be done at all, as CYP2D6-inhibition may do the opposite of fluvoxamine and increase desmethylclomipramine levels to an uncomfortable extent.
Pharmacology
Fluvoxamine is a potent selective serotonin reuptake inhibitor with around 100-fold affinity for the serotonin transporter over the norepinephrine transporter. It has negligible affinity for the dopamine transporter or any other site, with the sole exception of the σ1 receptor. It behaves as a potent agonist at this receptor and has the highest affinity (36 nM) of any SSRI for doing so. This may contribute to its antidepressant and anxiolytic effects and may also afford it some efficacy in treating the cognitive symptoms of depression. Unlike some other SSRIs, fluvoxamine's metabolites are pharmacologically neutral.
History
Fluvoxamine was developed by Kali-Duphar, part of Solvay Pharmaceuticals, Belgium, now Abbott Laboratories, and introduced as Floxyfral in Switzerland in 1983. It was approved by the U.S. Food and Drug Administration (FDA) in 1994, and introduced as Luvox in the US. In India, it is available, among several other brands, as Uvox by Abbott. It was one of the first SSRI antidepressants to be launched, and is prescribed in many countries to patients with major depression. It was the first SSRI, a non-TCA drug, approved by the U.S. FDA specifically for the treatment of OCD. At the end of 1995, more than ten million patients worldwide had been treated with fluvoxamine. Fluvoxamine was the first SSRI to be registered for the treatment of obsessive compulsive disorder in children by the FDA in 1997. In Japan, fluvoxamine was the first SSRI to be approved for the treatment of depression in 1999 and was later in 2005 the first drug to be approved for the treatment of social anxiety disorder. Fluvoxamine was the first SSRI approved for clinical use in the United Kingdom. Manufacturers include BayPharma, Synthon, and Teva, among others.
Research directions
While early studies have suggested potential benefits for fluvoxamine as an anti-inflammatory agent and a possible impact on reducing cytokine storms, further studies did not confirm this expected benefit on COVID-19 patients. A cytokine storm refers to an excessive immune response characterized by a release of large amounts of pro-inflammatory cytokines.
In May 2022, based on a review of available scientific evidence, the U.S. Food and Drug Administration (FDA) chose not to issue an emergency use authorization covering the use of fluvoxamine to treat COVID-19, saying that, at the time, the data was not sufficient to conclude that fluvoxamine may be effective in treating non-hospitalized people with COVID-19 to prevent serious illness or hospitalization. The agency stated that study results suggest that further clinical trials may be warranted.
Environment
Fluvoxamine is a common finding in waters near human settlement. Christensen et al. 2007 finds it is "very toxic to aquatic organisms" by European Union standards.
References
External links
AbbVie brands
Amines
Antidepressants
CYP1A2 inhibitors
CYP2D6 inhibitors
CYP3A4 inhibitors
Ethers
Ketoximes
Selective serotonin reuptake inhibitors
Sigma agonists
Trifluoromethyl compounds