Fluvoxamine; Uses, Dosage, Side Effects, Interactions

Fluvoxamine is a 2-aminoethyl oxime ether of aralkyl ketones, with an antidepressant, anti-obsessive-compulsive, and anxiolytic properties. Fluvoxamine, chemically unrelated to other selective serotonin reuptake inhibitors, selectively blocks serotonin reuptake by inhibiting the serotonin reuptake pump at the presynaptic neuronal membrane. This increases serotonin levels within the synaptic cleft, prolongs serotonergic transmission and decreased serotonin turnover, thereby leading to an antidepressant, anxiolytic and antiobsessive-compulsive effects. Fluvoxamine shows no significant affinity for histaminergic, alpha or beta adrenergic, muscarinic, or dopaminergic receptors in vitro.

Fluvoxamine an aralkyl ketones-derivative agent belongs to the class of medications called antidepressants known as selective serotonin reuptake inhibitors (SSRIs) that differs structurally from other SSRIs.It is used to treat depression and obsessive-compulsive disorder (OCD). It helps to reduce anxiety and unpleasant thoughts associated with OCD and improves mood by treating depression.

Mechanism of Action of Fluvoxamine

The exact mechanism of action of fluvoxamine has not been fully determined but appears to be linked to its inhibition of CNS neuronal uptake of serotonin. Fluvoxamine blocks the reuptake of serotonin at the serotonin reuptake pump of the neuronal membrane, enhancing the actions of serotonin on 5HT_1A autoreceptors. In-vitro studies suggest that fluvoxamine is more potent than clomipramine, fluoxetine, and desipramine as a serotonin-reuptake inhibitor. Studies have also demonstrated that fluvoxamine has virtually no affinity for α₁– or α₂-adrenergic, β-adrenergic, muscarinic, dopamine D₂, histamine H₁, GABA-benzodiazepine, opiate, 5-HT₁, or 5-HT₂ receptors.

Indications of Fluvoxamine

• Anxiety and stress
• Depression
• Obsessive compulsive disorder
• Anorexia/feeding problems
• Social anxiety disorder
• Body dysmorphic disorder
• Panic disorder
• Persistent depressive disorder
• Post traumatic stress disorder
• Somatoform pain disorder
• Bulimia nervosa
• Major depressive disorder
• Obsessive compulsive disorder
• Indicated predominantly for the management of depression and for Obsessive Compulsive Disorder (OCD) . Has also been used in the management of bulimia nervosa

Contra Indications of Fluvoxamine

• Syndrome of Inappropriate Antidiuretic Hormone Secretion
• low amount of sodium in the blood
• increased risk of bleeding
• Behaving with Excessive Cheerfulness and Activity
• Mild Degree of Mania

Manic-Depression

• Having Thoughts of Suicide
• serotonin syndrome – adverse drug interaction
• closed angle glaucoma
• liver problems
• Bleeding from Stomach
• Esophagus or Duodenum
• seizures
• tobacco smoking

Dosage of Fluvoxamine

Strengths: 25 mg; 50 mg; 100 mg; 150 mg

Obsessive Compulsive Disorder

• Initial extended release capsule dose: 100 mg orally once a day at bedtime
• Initial immediate release tablet dose: 50 mg orally once a day at bedtime
• Maintenance dose: 100 to 300 mg orally per day. The dose may be increased in 50 mg increments every 4 to 7 days, as tolerated until a maximum therapeutic benefit is achieved.
• Maximum Dose: 300 mg orally per day

Pediatric Dose for Obsessive Compulsive Disorder

8 to 11 years

• Initial dose: 25 mg orally once a day at bedtime
• Maintenance dose: 25 to 200 mg orally per day
• Maximum dose: 200 mg orally per day

Side Effects of Fluvoxamine

The most common

• clumsiness or unsteadiness
• dizziness
• drowsiness
• dry mouth
• false sense of well-being
• increased watering of mouth
• lightheadedness
• constipation;
• vision changes;
• breast swelling (in men or women); or
• decreased sex drive, impotence, or difficulty having an orgasm.
• blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• restless muscle movements in your eyes, tongue, jaw, or neck;
• a light-headed feeling, like you might pass out;

Common

• Drowsiness and lightheadedness the day after taking the medicine.
• Confusion.
• Numbed emotions.
• Visual disturbances such as blurred vision or double vision.
• Shaky movements and unsteady walk (ataxia).
• Loss of memory (amnesia).
• Muscle weakness.
• Dizziness.
• Headache.
• Skin rashes.
• Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting or abdominal pain.
• Difficulty in passing urine (urinary retention).
• Changes in sex drive.
• Low blood pressure (hypotension).
• Blood disorders.
• Jaundice.
• Unexpected aggression, restlessness or irritability (tell your doctor if you experience this).
• Nightmares or hallucinations (tell your doctor if you experience this).

Serious

• agitation
• anxiety
• behavioural changes, including aggressiveness, angry outbursts, bizarre behaviour, or decreased inhibitions
• confusion
• increased trouble sleeping
• memory problems
• muscle spasms
• shortness of breath
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• sleepwalking

Drug Interactions of Fluvoxamine

Fluvoxamine may interact with following drugs, supplements & may change the efficacy of drugs

• amlodipine
• general anesthetics
• antihistamines (e.g., cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• aripiprazole
• baclofen
• barbiturates (e.g., butalbital, pentobarbital, phenobarbital)
• benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
• bupropion
• celecoxib
• cilostazol
• clopidogrel
• cyclosporine
• diabetes medications (e.g., chlorpropamide, metformin, nateglinide, rosiglitazone)
• diltiazem
• estrogens (e.g., conjugated estrogen, )
• glucosamine
• heparin
• low molecular weight heparins
• mirtazapine
• monoamine oxidase inhibitors (MAOIs; e.g. rasagiline, selegiline, )
• multivitamins
• muscle relaxants
• nifedipine
• non-steroidal anti-inflammatory medications (NSAIDs; e.g., diclofenac, ibuprofen, naproxen)
• omega-3 fatty acids
• pentoxifylline
• propranolol
• quinolone antibiotics (e.g., ciprofloxacin, norfloxacin, ofloxacin)
• rasagiline
• seizure medications ( phenobarbital, phenytoin, valproic acid, )
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, duloxetine, fluoxetine, paroxetine, sertraline)
• serotonin antagonists (anti-emetic medications; e.g., granisetron, ondansetron)
• tapentadol
• theophyllines  (e.g., aminophylline, oxtriphylline, theophylline)
• thiazide diuretics (water pills; e.g., hydrochlorothiazide, )
• thyroid replacements (e.g., desiccated thyroid, levothyroxine)
• tizanidine
• tramadol
• tricyclic antidepressants (e.g., desipramine, nortriptyline)
• triptans (e.g., sumatriptan, rizatriptan)

Pregnancy & Lactation of Fluvoxamine

Pregnancy

It has been reported that babies born to women who took medications of this kind during the last trimester of their pregnancy may experience adverse effects (such as breathing problems, seizures, trouble feeding, jitteriness, irritability, and constant crying). This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Lactation

This medication passes into breast milk. If you breastfeeding-feeding mother and are taking fluvoxamine, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

References