Fluvoxamine is an antidepressant belonging to the group SSRIs (selective serotonin reuptake inhibitors). Fluvoxamine has been in use in clinical practice since 1983 in Switzerland. It was approved by the FDA in 1994 and introduced under the brand-name Luvox in the US. It was one of the first SSRI antidepressants to be launched and is prescribed in many countries to patients with major depression.
It is used primarily for the treatment of obsessive-compulsive disorder (OCD) in the US and is also used to treat depression and anxiety disorders, such as panic disorder, social anxiety disorder, and post-traumatic stress disorder. It works by increasing the amount of serotonin, a neurotransmitter in the brain that helps maintain mental balance or mood. Neurotransmitters are naturally occurring chemicals in the body that facilitate the passage of signals between nerve cells.
Uses of Fluvoxamine (Luvox)
Fluvoxamine is unique in that it is FDA-approved only for the treatment of OCD in the United States. This is a consequence of commercial considerations, not of any significant difference in its clinical profile. It shares the same therapeutic spectrum of activity with the other SSRIs and is widely used as a treatment of major depressive disorder in other countries worldwide.
Depression or major depressive disorder (MDD): Dosing is usually initiated at 25-50 mg/day. Patients with a major depressive disorder typically show responses over the range of 100-300 mg/day, although response is often seen in the range of 100-200 mg/day.
Obsessive-compulsive disorder (OCD): It is proven to be effective in a broad spectrum of anxiety and related disorders. But fluvoxamine is FDA-approved only for OCD. It is effective in treating both adults and children with OCD. In head-to-head studies with clomipramine, it may be as effective, but with fewer adverse effects. Adults with OCD are often started at a dose of 50 mg administered at bedtime. The dose may be increased by 50 mg every 4-7 days. The effective dosing range is 100-300 mg/day, with some patients responding to higher doses. Treatment of OCD in adolescents and children should start at 25 mg/day with 25-mg-per-day increases every 4-7 days. The effective dosing range is 50-200 mg/day. Adolescents often require a dose close to that used in adults, whereas children, perhaps owing to higher plasma fluvoxamine levels, may respond to the lower portion of the dosing range.
Social anxiety disorder (SAD): Fluvoxamine is a first-line treatment for SAD. There is good treatment response with it. Another benefit is its broad-spectrum efficacy for common comorbid disorders such as depression and panic disorder. The dose needed is 100-300 mg/day.
Generalized anxiety disorder (GAD): 300 mg daily of fluvoxamine is generally necessary.
Panic disorder (PD): Due to possible early activation of anxiety symptoms, treatment of panic disorder is best started at a dose of 25 mg/day for most patients, owing to increased sensitivity of side effects in this population. The typical effective dose is usually 100-200 mg/day.
Premature ejaculation (PE): Fluvoxamine delays ejaculation, and hence is useful in treating PE.
Selective mutism: Fluvoxamine is helpful in the treatment of selective mutism, and may be helpful especially in more severe cases. The black box warnings issued by the FDA regarding increased risks of suicidality with SSRI use in children and adolescents means it is now generally reserved for young people who do not respond to psychological interventions. Nevertheless, the findings of meta-analyses that the increase in absolute risk of suicide is very small, and recognition of the serious functional morbidity associated with chronic anxiety and avoidance in children and adolescents, would suggest that pharmacotherapy should not be unduly withheld in these situations.
Dissociative identity disorder: A subgroup of dissociative identity disorder patients show marked obsessive-compulsive symptoms (OCD) and may preferentially respond to antidepressants such as fluvoxamine (Luvox).
Paraphilias and nonparaphilic sex addictions: Fluvoxamine is useful in the treatment of paraphilias and nonparaphilic sex addictions, even in the absence of major depression. Some studies found that paraphilic patients with comorbid depression showed a concurrent decrease in paraphilic behavior when their depressive symptoms improved.
Fluvoxamine is also used to treat pruritus.
Skin picking disorder: There is benefit with treatment with fluvoxamine, and it is particularly effective in patients with prominent compulsive features, comorbid mood disorders, and anxiety disorders.
Trichotillomania (TTM): Fluvoxamine is the first-line choice medication treatment for TTM. It shows a positive treatment response with short-term and long-term benefits.
Kleptomania: Fluvoxamine is used successfully as monotherapy for Kleptomania. Combinations of medications have also been effective in case reports: fluvoxamine plus buspirone, and fluvoxamine plus valproate.
Dosage of Luvox
Fluvoxamine is available in 25-, 50-, and 100-mg scored tablets and 100- and 150-mg controlled-release capsules.
Fluvoxamine absorption is essentially unaffected by food. Maximal plasma concentrations are achieved 3 to 8 hours after dosing. Due to its short half-life, total daily doses of fluvoxamine greater than 50 mg should be administered as a split dose. Using the controlled release formulation obviates this need for divided doses.
It may take several weeks for you to feel the full benefit of fluvoxamine. Continue to take fluvoxamine even if you feel well. Do not stop taking fluvoxamine without talking to your doctor. If you suddenly stop taking fluvoxamine, you may experience withdrawal symptoms such as irritability, agitation, dizziness, extreme worry, uneasiness, confusion, headache, tiredness, mood changes, difficulty falling asleep or staying asleep, or pain, burning, numbness, tingling or ‘electric shock’ sensations in the hands or feet. The dose needs to be decreased gradually.
Side Effects of Luvox
Common side effects include:
- Sexual dysfunction
- Dry mouth
- Excessive sweating
- Less appetite
- Difficulty concentrating, memory problems, or confusion
Uncommon side effects include:
- Joint pains
- Confusional state
- Extrapyramidal side effects (e.g. dystonia, parkinsonism, tremor, etc.)
- Postural hypotension: That is, drop in blood pressure upon standing up quickly from sitting or lying down position
- Skin hypersensitivity reactions (e.g. buildup of fluid in the tissues, rash, itching)
SSRIs appear in breast milk to varying extents, but concentrations are lowest for fluvoxamine and sertraline.
Interactions of Fluvoxamine
- Giving fluvoxamine to a patient already taking clomipramine will result in increased clomipramine levels.
- Adverse reactions with lithium.
- Ramelteon should not be coadministered with fluvoxamine, which may inhibit the metabolism of ramelteon.
- Increased plasma tacrine levels with fluvoxamine. Close monitoring is needed when prescribing fluvoxamine and tacrine together.
- Fluvoxamine increases levels of HIV meds.
- Fluvoxamine (Luvox) concentrations increase 30 to 40 percent with abstinence from smoking. Therefore, it is important to monitor fluvoxamine doses in smokers where the quantity smoked is changing.
- It causes an increase in methadone levels, leading to excessive sedation.
- Immunosuppressive agents (tacrolimus, cyclosporine, sirolimus, mycophenolate mofetil) are inhibited by fluvoxamine.
- Coadministration with estrogen-containing compounds (e.g., oral contraceptives, hormone replacement therapies) may produce increases in levels of exposure to these agents.
- Increases in mirtazapine concentrations result from concomitant administration of fluvoxamine (Luvox).
- Fluvoxamine can cause increases in olanzapine levels.
- Administration of asenapine 5 mg with fluvoxamine (25 mg twice daily) for 8 days increased the asenapine AUC by 29 percent; caution is indicated for coadministration of asenapine and fluvoxamine.
- Theophylline, aminophylline (Phyllocontin), warfarin, propranolol (Inderal), and caffeine metabolism is inhibited by fluvoxamine.
- Increased serum levels of carbamazepine (Tegretol), clozapine, methadone (Dolophine), propranolol, amitriptyline, clomipramine, and imipramine have been reported after the addition of fluvoxamine treatment.
- Thioridazine (Mellaril) should not be combined with fluvoxamine owing to the potential drug-drug interaction and the potential for cardiac QTc interval prolongation secondary to the inhibition of thioridazine metabolism.
- The manufacturer warns against the coadministration of fluvoxamine with terfenadine (Seldane), astemizole (Hismanal), cisapride (Propulsid), and pimozide (Orap).
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