From the Guidelines
Fluvoxamine can cause a wide range of side effects, including common effects such as nausea, dry mouth, diarrhea, headache, somnolence, insomnia, dizziness, and changes in appetite, as well as more serious but less common effects like suicidal thinking and behavior, behavioral activation/agitation, hypomania, mania, sexual dysfunction, seizures, abnormal bleeding, and serotonin syndrome 1.
Common Side Effects
- Nausea
- Dry mouth
- Diarrhea
- Headache
- Somnolence
- Insomnia
- Dizziness
- Changes in appetite
- Weight loss or gain
- Fatigue
- Nervousness
- Tremor
- Bruxism
- Diaphoresis ### Serious Side Effects
- Suicidal thinking and behavior
- Behavioral activation/agitation
- Hypomania
- Mania
- Sexual dysfunction
- Seizures
- Abnormal bleeding
- Serotonin syndrome As noted in the clinical practice guideline for the assessment and treatment of children and adolescents with anxiety disorders, fluvoxamine, like other SSRIs, is generally well tolerated but can have significant side effects, especially when not monitored properly 1.
Special Considerations
- Fluvoxamine may have a greater potential for drug-drug interactions due to its effect on various CYP enzymes, including CYP1A2, CYP2C19, CYP2C9, CYP3A4, and CYP2D6 2.
- A discontinuation syndrome has been reported with fluvoxamine, characterized by dizziness, fatigue, lethargy, general malaise, myalgias, chills, headaches, nausea, vomiting, diarrhea, insomnia, imbalance, vertigo, sensory disturbances, paresthesias, anxiety, irritability, and agitation 2. It is essential for healthcare providers to closely monitor patients on fluvoxamine, especially during the initial treatment phase and when adjusting doses, to minimize the risk of adverse effects and ensure the best possible outcome for the patient 1, 2.
From the FDA Drug Label
ADVERSE REACTIONS Associated with Discontinuation of Treatment Of the 1087 OCD and depressed patients treated with fluvoxamine maleate in controlled clinical trials conducted in North America, 22% discontinued treatment due to an adverse event. The most common events (≥1%) associated with discontinuation and considered to be drug related (i.e., those events associated with dropout at a rate at least twice that of placebo) included: Table 2 ADVERSE EVENTS ASSOCIATED WITH DISCONTINUATION OF TREATMENT IN OCD AND DEPRESSION POPULATIONS BODY SYSTEM/ADVERSE EVENTPERCENTAGE OF PATIENTS FLUVOXAMINEPLACEBO BODY AS A WHOLE Headache3%1% Asthenia2%<1% Abdominal Pain1%0% DIGESTIVE Nausea9%1% Diarrhea1%<1% Vomiting2%<1% Anorexia1%<1% Dyspepsia1%<1% NERVOUS SYSTEM Insomnia4%1% Somnolence4%<1% Nervousness2%<1% Agitation2%<1% Dizziness2%<1% Anxiety1%<1% Dry mouth1%<1% Incidence in Controlled Trials Commonly Observed Adverse Events in Controlled Clinical Trials Fluvoxamine Maleate Tablets have been studied in controlled trials of OCD (N=320) and depression (N=1350) In general, adverse event rates were similar in the two data sets as well as in the pediatric OCD study The most commonly observed adverse events associated with the use of Fluvoxamine Maleate Tablets and likely to be drug-related (incidence of 5% or greater and at least twice that for placebo) derived from TABLE 2 were: somnolence, insomnia, nervousness, tremor, nausea, dyspepsia, anorexia, vomiting, abnormal ejaculation, asthenia, and sweating In a pool of two studies involving only patients with OCD, the following additional events were identified using the above rule: dry mouth, decreased libido, urinary frequency, anorgasmia, rhinitis and taste perversion In a study of pediatric patients with OCD, the following additional events were identified using the above rule: agitation, depression, dysmenorrhea, flatulence, hyperkinesia, and rash Adverse Events Occurring at an Incidence of 1% Table 2 enumerates adverse events that occurred in adults at a frequency of 1% or more, and were more frequent than in the placebo group, among patients treated with Fluvoxamine Maleate Tablets in two short-term placebo controlled OCD trials (10 week) and depression trials (6 week) in which patients were dosed in a range of generally 100 to 300 mg/day This table shows the percentage of patients in each group who had at least one occurrence of an event at some time during their treatment. Reported adverse events were classified using a standard COSTART-based Dictionary terminology The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors may differ from those that prevailed in the clinical trials Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and non-drug factors to the side-effect incidence rate in the population studied Table 3 TREATMENT-EMERGENT ADVERSE EVENT INCIDENCE RATES BY BODY SYSTEM IN ADULT OCD AND DEPRESSION POPULATIONS COMBINED* Percentage Of Patients Reporting Event BODY SYSTEM/ADVERSE EVENTFLUVOXAMINEPLACEBO N = 892N = 778
- Events for which fluvoxamine maleate incidence was equal to or less than placebo are not listed in the table above, but include the following: abdominal pain, abnormal dreams, appetite increase, back pain, chest pain, confusion, dysmenorrhea, fever, infection, leg cramps, migraine, myalgia, pain, paresthesia, pharyngitis, postural hypotension, pruritus, rash, rhinitis, thirst and tinnitus. † Includes "toothache," "tooth extraction and abscess," and "caries." ‡ Mostly feeling warm, hot, or flushed. § Mostly "blurred vision." ¶ Mostly "delayed ejaculation. " # Incidence based on number of male patients ERVOUS SYSTEM Somnolence228 Insomnia2110 Dry Mouth1410 Nervousness125 Dizziness116 Tremor51 Anxiety53 Vasodilatation‡31 Hypertonia21 Agitation21 Decreased Libido21 Depression21 CNS Stimulation21 RESPIRATORY SYSTEM Upper Respiratory Infection95 Dyspnea21 Yawn20 SKIN Sweating73 SPECIAL SENSES Taste Perversion31 Amblyopia§32 UROGENITAL Abnormal Ejaculation¶, #81 Urinary Frequency32 Impotence#21 Anorgasmia20 Urinary Retention10 Adverse Events in OCD Placebo Controlled Studies Which are Markedly Different (defined as at least a two-fold difference) in rate from the Pooled Event Rates in OCD and Depression Placebo Controlled Studies The events in OCD studies with a two-fold decrease in rate compared to event rates in OCD and depression studies were dysphagia and amblyopia (mostly blurred vision) Additionally, there was an approximate 25% decrease in nausea
The side effects of fluvoxamine include:
- Common side effects: + Somnolence + Insomnia + Nervousness + Tremor + Nausea + Dyspepsia + Anorexia + Vomiting + Abnormal ejaculation + Asthenia + Sweating
- Less common side effects: + Dry mouth + Decreased libido + Urinary frequency + Anorgasmia + Rhinitis + Taste perversion + Agitation + Depression + Dysmenorrhea + Flatulence + Hyperkinesia + Rash
- Rare but serious side effects: + Abnormal bleeding + Activation of mania/hypomania + Seizures + Hyponatremia + Serotonin syndrome + Allergic reactions 3 4 5
From the Research
Side Effects of Fluvoxamine
The side effects of fluvoxamine include:
- Nausea, which was the only adverse event occurring in >10% of patients 6
- Somnolence, asthenia, headache, dry mouth, and insomnia, which were less commonly reported events 6
- Suicidal thoughts, which are a core symptom of depression, but fluvoxamine is of particular benefit in reducing their occurrence 7
- Serotonin syndrome, which is a rare but potentially lethal condition, with an estimated incidence of 0.006-0.04 per 100 treatment days 8
- Psychosis-like side effects, such as reversible change of mental status with insomnia, agitation, confusion, and incoherent thoughts, which occurred in 3 patients out of 200 8
- Sexual dysfunction and withdrawal syndrome, which are associated with a low risk 6
- Anticholinergic or cardiovascular events, which are fewer than those associated with tricyclic antidepressants 6
Rare but Serious Side Effects
- Serotonin syndrome, which can occur when fluvoxamine is taken with other SSRIs or certain other medications 9
- Suicidal behavior, which is a risk factor in major depressive disorder, but fluvoxamine is not associated with an increased risk of emergence of substantial suicidal thoughts among depressed patients 10