FLUVOXAMINE Drug Interactions: What You Need to Know

INTERACTIONS Drug Interactions (not described in Contraindications or Warnings and Precautions) include the following: Drugs Inhibiting or Metabolized by Cytochrome P450: Fluvoxamine inhibits several cytochrome P450 isoenzymes (CYP1A2, CYP2C9, CYP3A4, and CYP2C19) ( 7.1 ) . Carbamazepine: Elevated carbamazepine levels and symptoms of toxicity with co-administration ( 7.2 ) . Sumatriptan: Rare postmarketing reports of weakness, hyperreflexia, and incoordination following use of an SSRI and sumatriptan. Monitor appropriately if concomitant treatment is clinically warranted ( 7.2 ) . Tacrine: Co-administration increased tacrine C max and AUC five- and eight-fold and caused nausea, vomiting, sweating, and diarrhea ( 7.2 ) .

Tricyclic

Antidepressants (TCAs): Co-administration significantly increased plasma TCA levels. Use caution; monitor plasma TCA levels; reduce TCA dose if indicated ( 7.2 ) . Tryptophan: Severe vomiting with co-administration ( 7.2 ) . Diltiazem: Bradycardia with co-administration ( 7.3 ) . Propranolol or Metoprolol: Reduce dose if co-administered with fluvoxamine and titrate more cautiously ( 7.3 ) .

7.1 Potential Interactions with Drugs that Inhibit or are Metabolized by Cytochrome P450 Isoenzymes Multiple hepatic cytochrome P450 isoenzymes are involved in the oxidative biotransformation of a large number of structurally different drugs and endogenous compounds. The available knowledge concerning the relationship of fluvoxamine and the cytochrome P450 isoenzyme system has been obtained mostly from pharmacokinetic interaction studies conducted in healthy volunteers, but some preliminary in vitro data are also available. Based on a finding of substantial interactions of fluvoxamine with certain of these drugs [ see later parts of this section and also Warnings and Precautions ( 5) for details ] and limited in vitro data for CYP3A4, it appears that fluvoxamine inhibits several cytochrome P450 isoenzymes that are known to be involved in the metabolism of other drugs such as: CYP1A2 (e.g., warfarin, theophylline, propranolol, tizanidine), CYP2C9 (e.g., warfarin), CYP3A4 (e.g., alprazolam), and CYP2C19 (e.g., omeprazole). In vitro data suggest that fluvoxamine is a relatively weak inhibitor of CYP2D6.

Approximately

7% of the normal population has a genetic code that leads to reduced levels of activity of CYP2D6 enzyme. Such individuals have been referred to as “poor metabolizers” (PM) of drugs such as debrisoquin, dextromethorphan, and tricyclic antidepressants. While none of the drugs studied for drug interactions significantly affected the pharmacokinetics of fluvoxamine, an in vivo study of fluvoxamine single-dose pharmacokinetics in 13 PM subjects demonstrated altered pharmacokinetic properties compared to 16 “extensive metabolizers” (EM): mean C max , AUC, and half-life were increased by 52%, 200%, and 62%, respectively, in the PM compared to the EM group. This suggests that fluvoxamine is metabolized, at least in part, by CYP2D6. Caution is indicated in patients known to have reduced levels of cytochrome P450 2D6 activity and those receiving concomitant drugs known to inhibit this cytochrome P450 isoenzyme (e.g., quinidine). The metabolism of fluvoxamine has not been fully characterized and the effects of potent cytochrome P450 isoenzyme inhibition, such as the ketoconazole inhibition of CYP3A4, on fluvoxamine metabolism have not been studied. A clinically significant fluvoxamine interaction is possible with drugs having a narrow therapeutic ratio such as pimozide, warfarin, theophylline, certain benzodiazepines, omeprazole, and phenytoin. If fluvoxamine maleate extended-release capsules are to be administered together with a drug that is eliminated via oxidative metabolism and has a narrow therapeutic window, plasma levels and/or pharmacodynamic effects of the latter drug should be monitored closely, at least until steady-state conditions are reached [see Contraindications ( 4) and Warnings and Precaution s ( 5 )] .

7.2 CNS Active Drugs Antipsychotics: See Warnings and Precautions ( 5.2 ) . Benzodiazepines: See Warnings and Precautions ( 5.9 ) . Alprazolam: See Warnings and Precautions ( 5.9 ) . Diazepam: See Warnings and Precautions ( 5.9 ) . Lorazepam : A study of multiple doses of immediate-release fluvoxamine maleate tablets (50 mg given twice daily) in healthy male volunteers (N = 12) and a single dose of lorazepam (4 mg single dose) indicated no significant pharmacokinetic interaction. On average, both lorazepam alone and lorazepam with fluvoxamine produced substantial decrements in cognitive functioning; however, the co-administration of fluvoxamine and lorazepam did not produce larger mean decrements compared to lorazepam alone. Alcohol: Studies involving single 40 g doses of ethanol (oral administration in one study and intravenous in the other) and multiple dosing with immediate-release fluvoxamine maleate tablets (50 mg given twice daily) revealed no effect of either drug on the pharmacokinetics or pharmacodynamics of the other. As with other psychotropic medications, patients should be advised to avoid alcohol while taking fluvoxamine maleate extended-release capsules. Carbamazepine: Elevated carbamazepine levels and symptoms of toxicity have been reported with the co-administration of immediate-release fluvoxamine maleate tablets and carbamazepine. Clozapine: See Warnings and Precautions ( 5.9 ) . Lithium: As with other serotonergic drugs, lithium may enhance the serotonergic effects of fluvoxamine and, therefore, the combination should be used with caution. Seizures have been reported with the co-administration of immediate-release fluvoxamine maleate tablets and lithium. Methadone: See Warnings and Precautions ( 5.9 ) .

Monoamine Oxidase

Inhibitors: See Contraindications ( 4.1 ) and Warnings and Precautions ( 5.2 ) . Pimozide: See Contraindications ( 4 ) and Warnings and Precautions ( 5.6 ) . Ramelteon: See Contraindications ( 4 ) and Warnings and Precautions ( 5.8 ) .

Serotonergic

Drugs: See Warnings and Precautions ( 5.2 ). Tacrine: In a study of 13 healthy, male volunteers, a single 40 mg dose of tacrine added to immediate-release fluvoxamine maleate tablets 100 mg/day administered at steady-state was associated with 5- and 8-fold increases in tacrine C max and AUC, respectively, compared to the administration of tacrine alone. Five subjects experienced nausea, vomiting, sweating, and diarrhea following co-administration, consistent with the cholinergic effects of tacrine. Thioridazine: See Contraindications ( 4 ) and Warnings and Precautions ( 5.4 ) . Tizanidine: See Contraindications ( 4 ) and Warnings and Precautions ( 5.5 ) .

Tricyclic

Antidepressants (TCAs): Significantly increased plasma TCA levels have been reported with the co-administration of immediate-release fluvoxamine maleate tablets and amitriptyline, clomipramine or imipramine. Caution is indicated with the co-administration of fluvoxamine maleate extended-release capsules and TCAs; plasma TCA concentrations may need to be monitored, and the dose of TCA may need to be reduced. Triptans: There have been rare postmarketing reports of serotonin syndrome with use of an SSRI and a triptan. If concomitant treatment of fluvoxamine maleate extended-release capsules with a triptan is clinically warranted, careful observation of the patient is advised, particularly during treatment initiation and dose increases [ see Warnings and Precautions ( 5.2 )] . Sumatriptan - There have been rare postmarketing reports describing patients with weakness, hyperreflexia, and incoordination following the use of a selective serotonin reuptake inhibitor (SSRI) and sumatriptan. If concomitant treatment with sumatriptan and an SSRI (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline) is clinically warranted, appropriate observation of the patient is advised. Tryptophan: Tryptophan may enhance the serotonergic effects of fluvoxamine, and the combination should, therefore, be used with caution. Severe vomiting has been reported with the co-administration of immediate-release fluvoxamine maleate tablets and tryptophan [ see Warnings and Precautions ( 5.2 )] .

7.3 Other Drugs Alosetron: See Contraindications (4) , Warnings and Precautions (5.7) , and Lotronex ® (alosetron) package insert. Digoxin: Administration of immediate-release fluvoxamine maleate tablets 100 mg daily for 18 days (N = 8) did not significantly affect the pharmacokinetics of a 1.25 mg single intravenous dose of digoxin. Diltiazem: Bradycardia has been reported with the co-administration of immediate-release fluvoxamine maleate tablets and diltiazem. Mexiletine: See Warnings and Precautions (5.9) . Propranolol and Other Beta-Blockers: Co-administration of immediate-release fluvoxamine maleate tablets 100 mg per day and propranolol 160 mg per day in normal volunteers resulted in a mean five-fold increase (range 2 to 17) in minimum propranolol plasma concentrations. In this study, there was a slight potentiation of the propranolol-induced reduction in heart rate and reduction in the exercise diastolic pressure. One case of bradycardia and hypotension and a second case of orthostatic hypotension have been reported with the co-administration of immediate-release fluvoxamine maleate tablets and metoprolol. If propranolol or metoprolol is co-administered with fluvoxamine maleate extended-release capsules, a reduction in the initial beta-blocker dose and more cautious dose titration are recommended. No dosage adjustment is required for fluvoxamine maleate extended-release capsules. Co-administration of immediate-release fluvoxamine maleate tablets 100 mg per day with atenolol 100 mg per day (N = 6) did not affect the plasma concentrations of atenolol. Unlike propranolol and metoprolol, which undergo hepatic metabolism, atenolol is eliminated primarily by renal excretion. Theophylline: See Warnings and Precautions (5.9) . Warfarin and Other Drugs that Interfere with Hemostasis (NSAIDs, Aspirin, etc.): See Warnings and Precautions (5.9 , 5.11) .

7.4 Effects of Smoking on Fluvoxamine Metabolism Smokers had a 25% increase in the metabolism of fluvoxamine compared to non-smokers.

7.5 Electroconvulsive Therapy (ECT) There are no clinical studies establishing the benefits or risks of combined use of ECT and fluvoxamine maleate.

7.6 Monoamine Oxidase Inhibitors (MAOIs)

See

Dosage and Administration ( 2.6 , 2.7 ) , Contraindications ( 4.1 ) , Warnings and Precautions ( 5.2 ) .

7.7 Serotonergic Drugs See Dosage and Administration ( 2.6 , 2.7 ) , Contraindications ( 4.1 ) , Warnings and Precautions ( 5.2 ) .

Co-administration of thioridazine, tizanidine, pimozide, alosetron, or ramelteon with fluvoxamine maleate extended-release capsules is contraindicated [see Warnings and Precautions ( 5.4 to 5.8 )] . Co-administration of thioridazine, tizanidine, pimozide, alosetron, or ramelteon ( 4 ) .

Serotonin

Syndrome and MAOIs: Do not use MAOIs intended to treat psychiatric disorders with fluvoxamine maleate extended-release capsules or within 14 days of stopping treatment with fluvoxamine maleate extended-release capsules. Do not use fluvoxamine maleate extended-release capsules within 14 days of stopping an MAOI intended to treat psychiatric disorders. In addition, do not start fluvoxamine maleate extended-release capsules in a patient who is being treated with linezolid or intravenous methylene blue ( 4.1 ) .

4.1 Monoamine Oxidase Inhibitors (MAOIs) The use of MAOIs intended to treat psychiatric disorders with fluvoxamine maleate extended‑release capsules or within 14 days of stopping treatment with fluvoxamine maleate extended-release capsules is contraindicated because of an increased risk of serotonin syndrome. The use of fluvoxamine maleate extended-release capsules within 14 days of stopping an MAOI intended to treat psychiatric disorders is also contraindicated [ see Dosage and Administration ( 2.5 ) and Warnings and Precautions ( 5.2 )] . Starting fluvoxamine maleate extended-release capsules in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome [ see Dosage and Administration ( 2.6 ) and Warnings and Precautions ( 5.2 )] .

AND PRECAUTIONS Clinical Worsening/Suicide Risk: Monitor for clinical worsening of suicidal thoughts/behaviors especially during the initial months of therapy and at times of dose changes ( 5.1 ) .

Bipolar

Disorder: Screen for bipolar disorder ( 5.1 ) .

Serotonin

Syndrome: Serotonin syndrome has been reported with SSRIs and SNRIs, including fluvoxamine maleate extended-release capsules, both when taken alone, but especially when coadministered with other serotonergic agents. If such symptoms occur, discontinue fluvoxamine maleate extended-release capsules and serotonergic agents and initiate supportive treatment. If concomitant use of fluvoxamine maleate extended-release capsules with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases ( 5.2 ) .

Angle Closure

Glaucoma: Angle closure glaucoma has occurred in patients with untreated anatomically narrow angles treated with antidepressants ( 5.3 ).

Other Potentially Important Drug

Interactions: Benzodiazepines: Use with caution. Coadministration with diazepam is generally not advisable ( 5.9 ) . Clozapine: Clozapine levels may be increased and produce orthostatic hypotension or seizures ( 5.9 ) . Methadone: Coadministration may produce opioid intoxication. Discontinuation of fluvoxamine may produce opioid withdrawal ( 5.9 ) . Mexiletine: Monitor serum mexiletine levels ( 5.9 ) . Theophylline: Clearance decreased; reduce theophylline dose by one-third ( 5.9 ) . Warfarin: Plasma concentrations increased and prothrombin times prolonged; monitor prothrombin time and adjust warfarin dose accordingly ( 5.9 ) . Discontinuation: Symptoms associated with discontinuation have been reported ( 5.10 ) . In the absence of an emergency, abrupt discontinuation not recommended ( 2.7 , 5.2 ) .

Abnormal

Bleeding: May increase bleeding risk, especially when used with NSAIDs, aspirin, warfarin, or other drugs that affect coagulation ( 5.11 ) . Activation of Mania/Hypomania has occurred ( 5.12 ) . Seizures: Avoid administering fluvoxamine in patients with unstable epilepsy; monitor patients with controlled epilepsy; discontinue treatment if seizures occur or frequency increases ( 5.13 ) . Hyponatremia: May occur with SSRIs and SNRIs, including fluvoxamine maleate extended-release capsules. The elderly may be at increased risk. Consider discontinuing in patients with symptomatic hyponatremia ( 5.14 ) .

Concomitant

Illness: Use caution in patients with diseases or conditions that affect hemodynamic responses or metabolism. Patients with impaired liver function may require a lower starting dose and slower titration ( 5.15 ) .

Sexual

Dysfunction : Fluvoxamine maleate extended-release capsules may cause symptoms of sexual dysfunction. ( 5.17)

5.1 Clinical Worsening and Suicide Risk Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. There has been a long-standing concern, however, that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. The pooled analyses of short-term placebo-controlled trials of antidepressant drugs (SSRIs and others) showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults (ages 18 to 24) with major depressive disorder (MDD) and other psychiatric disorders. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction with antidepressants compared to placebo in adults age 65 and older. The pooled analyses of placebo-controlled trials in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials of 9 antidepressant drugs in over 4400 patients. The pooled analyses of placebo-controlled trials in adults with MDD or other psychiatric disorders included a total of 295 short-term trials (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across the different indications, with the highest incidence in MDD. The risk differences (drug vs placebo), however, were relatively stable within age strata and across indications. These risk differences (drug-placebo difference in the number of cases of suicidality per 1000 patients treated) are provided in Table 1 . TABLE 1 DRUG-PLACEBO DIFFERENCES IN NUMBER OF CASES OF SUICIDALITY PER 1000 PATIENTS TREATED Age Range Drug-Related Increases <18 14 additional cases 18 to 24 5 additional cases Age Range Drug-Related Decreases 25 to 64 1 fewer case ≥ 65 6 fewer cases No suicides occurred in any of the pediatric trials. There were suicides in the adult trials, but the number was not sufficient to reach any conclusion about the drug effect on suicide. It is unknown whether the suicidality risk extends to longer-term use, i.e., beyond several months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with depression that the use of antidepressants can delay the recurrence of depression. All patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases. The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality. Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse, or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient’s presenting symptoms. If the decision has been made to discontinue treatment, medication should be tapered, as rapidly as is feasible, but with recognition that abrupt discontinuation can be associated with certain symptoms (see DOSAGE AND ADMINISTRATION–Discontinuation of Treatment with Fluvoxamine Maleate Extended-Release Capsules [ 2.7 ] , for a description of the risks of discontinuation of Fluvoxamine Maleate Extended-Release Capsules ). Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to health care providers. Such monitoring should include daily observation by families and caregivers. Prescriptions for fluvoxamine maleate extended-release capsules should be written for the smallest quantity of capsules consistent with good patient management, in order to reduce the risk of overdose.

Screening

Patients for Bipolar Disorder: A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed (though not established in controlled trials) that treating such an episode with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. Whether any of the symptoms described above represent such a conversion is unknown. However, prior to initiating treatment with an antidepressant, patients with depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. It should be noted that fluvoxamine maleate extended-release capsules are not approved for use in treating bipolar depression.

5.2 Serotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including fluvoxamine maleate extended-release capsules, alone but particularly with concomitant use of serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, meperidine, methadone, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. John’s Wort), and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). Patients should be monitored for the emergence of serotonin syndrome. The concomitant use of fluvoxamine maleate extended-release capsules with MAOIs intended to treat psychiatric disorders is contraindicated. Fluvoxamine maleate extended-release capsules should also not be started in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue. All reports with methylene blue that provided information on the route of administration involved intravenous administration in the dose range of 1 mg/kg to 8 mg/kg. No reports involved the administration of methylene blue by other routes (such as oral tablets or local tissue injection) or at lower doses. There may be circumstances when it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking fluvoxamine maleate extended-release capsules. Fluvoxamine maleate extended-release capsules should be discontinued before initiating treatment with the MAOI (see CONTRAINDICATIONS [4.1] and DOSAGE AND ADMINISTRATION [ 2.5 , 2.6 ] ). If concomitant use of fluvoxamine maleate extended-release capsules with other serotonergic drugs, including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, amphetamines, and St. John's Wort, is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases. Treatment with fluvoxamine maleate extended-release capsules and any concomitant serotonergic agents should be discontinued immediately if the above events occur, and supportive symptomatic treatment should be initiated.

5.3 Angle Closure Glaucoma Angle Closure Glaucoma: The pupillary dilation that occurs following use of many antidepressant drugs including fluvoxamine maleate extended-release capsules may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.

5.4 Potential Thioridazine Interaction The effect of fluvoxamine (25 mg immediate-release tablets given twice daily for one week) on thioridazine steady-state concentrations was evaluated in 10 male inpatients with schizophrenia. Concentrations of thioridazine and its two active metabolites, mesoridazine and sulforidazine, increased 3-fold following coadministration of fluvoxamine. Thioridazine administration produces a dose-related prolongation of the QTc interval, which is associated with serious ventricular arrhythmias, such as torsades de pointes-type arrhythmias, and sudden death. It is likely that this experience underestimates the degree of risk that might occur with higher doses of thioridazine. Moreover, the effect of fluvoxamine may be even more pronounced when it is administered at higher doses. Therefore, fluvoxamine maleate extended-release capsules should not be coadministered with thioridazine (see CONTRAINDICATIONS [ 4 ]) .

5.5 Potential Tizanidine Interaction Fluvoxamine is a potent inhibitor of CYP1A2, and tizanidine is a CYP1A2 substrate. The effect of immediate-release fluvoxamine maleate tablets (100 mg daily for four days) on the pharmacokinetics and pharmacodynamics of a single dose of tizanidine has been studied in 10 healthy male subjects. Tizanidine C max was increased approximately 12-fold (range 5-fold to 32-fold), elimination half-life was increased by almost 3-fold, and AUC increased 33-fold (range 14-fold to 103-fold). The mean maximal effect on blood pressure was a 35 mm Hg decrease in systolic blood pressure, a 20 mm Hg decrease in diastolic blood pressure, and a 4 beat/min decrease in heart rate. Drowsiness was significantly increased, and performance on the psychomotor task was significantly impaired. Fluvoxamine maleate extended-release capsules and tizanidine should not be used together (see CONTRAINDICATIONS [ 4 ] ).

5.6 Potential Pimozide Interaction Pimozide is metabolized by the CYP3A4 isozyme and it has been demonstrated that ketoconazole, a potent inhibitor of CYP3A4, blocks the metabolism of this drug, resulting in increased plasma concentrations of parent drug. An increased plasma concentration of pimozide causes QT prolongation and has been associated with torsades de pointes-type ventricular tachycardia, sometimes fatal. As noted below, a substantial pharmacokinetic interaction has been observed for fluvoxamine in combination with alprazolam, a drug that is known to be metabolized by the CYP3A4 isozyme. Although it has not been definitively demonstrated that fluvoxamine is a potent CYP3A4 inhibitor, it is likely to be, given the substantial interaction of fluvoxamine with alprazolam. Consequently, it is recommended that fluvoxamine not be used in combination with pimozide (see CONTRAINDICATIONS [ 4 ] ).

5.7 Potential Alosetron Interaction In a pharmacokinetic study, 40 healthy female subjects received fluvoxamine in escalating doses from 50 to 200 mg/day for 16 days with coadministration of alosetron 1 mg on the last day. Fluvoxamine increased mean alosetron plasma concentrations (AUC) approximately 6-fold and prolonged the half-life by approximately 3-fold. Consequently, it is recommended that fluvoxamine maleate extended-release capsules not be used in combination with alosetron (see CONTRAINDICATIONS [ 4 ] and Lotronex ® (alosetron) package insert).

5.8 Potential Ramelteon Interaction When immediate-release fluvoxamine maleate tablets 100 mg twice daily were administered for 3 days prior to single-dose coadministration of ramelteon 16 mg and immediate-release fluvoxamine maleate tablets, the AUC for ramelteon increased approximately 190-fold and the C max increased approximately 70-fold compared to ramelteon administered alone. Ramelteon should not be used in combination with fluvoxamine maleate extended-release capsules (see CONTRAINDICATIONS [ 4 ] ).

5.9 Other Potentially Important Drug Interactions Benzodiazepines: Benzodiazepines metabolized by hepatic oxidation (e.g., alprazolam, midazolam, triazolam, etc.) should be used with caution because the clearance of these drugs is likely to be reduced by fluvoxamine. The clearance of benzodiazepines metabolized by glucuronidation (e.g., lorazepam, oxazepam, temazepam) is unlikely to be affected by fluvoxamine. Alprazolam - When immediate-release fluvoxamine maleate tablets (100 mg given once daily) and alprazolam (1 mg given 4 times per day) were coadministered to steady state, plasma concentrations and other pharmacokinetic parameters (AUC, C max , T ½ ) of alprazolam were approximately twice those observed when alprazolam was administered alone; oral clearance was reduced by about 50%. The elevated plasma alprazolam concentrations resulted in decreased psychomotor performance and memory. This interaction, which has not been investigated using higher doses of fluvoxamine, may be more pronounced if a 300 mg daily dose is coadministered, particularly since fluvoxamine exhibits non-linear pharmacokinetics over the dosage range 100 to 300 mg. If alprazolam is coadministered with fluvoxamine maleate extended-release capsules, the initial alprazolam dosage should be at least halved and titration to the lowest effective dose is recommended. No dosage adjustment is required for fluvoxamine maleate extended-release capsules. Diazepam - The coadministration of fluvoxamine maleate extended-release capsules and diazepam is generally not advisable. Because fluvoxamine reduces the clearance of both diazepam and its active metabolite, N-desmethyldiazepam, there is a strong likelihood of substantial accumulation of both species during chronic coadministration. Evidence supporting the conclusion that it is inadvisable to coadminister fluvoxamine and diazepam is derived from a study in which healthy volunteers taking 150 mg/day of immediate-release fluvoxamine maleate tablets were administered a single oral dose of 10 mg of diazepam. In these subjects (N=8), the clearance of diazepam was reduced by 65% and that of N-desmethyldiazepam to a level that was too low to measure over the course of the 2-week-long study. It is likely that this experience significantly underestimates the degree of accumulation that might occur with repeated diazepam administration. Moreover, as noted with alprazolam, the effect of fluvoxamine may even be more pronounced when it is administered at higher doses. Accordingly, diazepam and fluvoxamine should not ordinarily be coadministered. Clozapine: Elevated serum levels of clozapine have been reported in patients taking immediate-release fluvoxamine maleate tablets and clozapine. Since clozapine-related seizures and orthostatic hypotension appear to be dose related, the risk of these adverse reactions may be higher when fluvoxamine and clozapine are coadministered. Patients should be closely monitored when fluvoxamine maleate extended-release capsules and clozapine are used concurrently. Methadone: Significantly increased methadone (plasma level: dose) ratios have been reported when immediate-release fluvoxamine maleate tablets were administered to patients receiving maintenance methadone treatment, with symptoms of opioid intoxication in one patient. Opioid withdrawal symptoms were reported following fluvoxamine maleate discontinuation in another patient. Mexiletine: The effect of steady-state fluvoxamine (50 mg given twice daily for 7 days) on the single dose pharmacokinetics of mexiletine (200 mg) was evaluated in 6 healthy Japanese males. The clearance of mexiletine was reduced by 38% following coadministration with fluvoxamine compared to mexiletine alone. If fluvoxamine and mexiletine are coadministered, serum mexiletine levels should be monitored. Theophylline: The effect of steady-state immediate-release fluvoxamine maleate tablets (50 mg tablets given twice daily) on the pharmacokinetics of a single dose of theophylline (375 mg as 442 mg aminophylline) was evaluated in 12 healthy non-smoking, male volunteers. The clearance of theophylline was decreased approximately 3-fold. Therefore, if theophylline is coadministered with fluvoxamine maleate, its dose should be reduced to one-third of the usual daily maintenance dose and plasma concentrations of theophylline should be monitored. No dosage adjustment is required for fluvoxamine maleate extended-release capsules. Warfarin and Other Drugs That Interfere With Hemostasis (NSAIDs, Aspirin, etc.): Serotonin release by platelets plays an important role in hemostasis. Epidemiological studies of the case-control and cohort design have demonstrated an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of upper gastrointestinal bleeding. These studies have also shown that concurrent use of an NSAID or aspirin may potentiate this risk of bleeding. Thus, patients should be cautioned about the use of such drugs concurrently with fluvoxamine (see WARNINGS AND PRECAUTIONS-Abnormal Bleeding [ 5.11 ] ). Warfarin - When immediate-release fluvoxamine maleate tablets (50 mg given three times daily) were administered concomitantly with warfarin for two weeks, warfarin plasma concentrations increased by 98% and prothrombin times were prolonged. Thus patients receiving oral anticoagulants and fluvoxamine maleate extended-release capsules should have their prothrombin time monitored and their anticoagulant dose adjusted accordingly. No dosage adjustment is required for fluvoxamine maleate extended-release capsules.

5.10 Discontinuation of Treatment with Fluvoxamine Maleate Extended-Release Capsules During marketing of immediate-release fluvoxamine maleate tablets and other SSRIs and SNRIs (serotonin and norepinephrine reuptake inhibitors), there have been spontaneous reports of adverse reactions occurring upon discontinuation of these drugs, particularly when abrupt, including the following: dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g., paresthesias, such as electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, and hypomania. While these reactions are generally self-limiting, there have been reports of serious discontinuation symptoms. Patients should be monitored for these symptoms when discontinuing treatment with fluvoxamine maleate extended-release capsules. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the health care provider may continue decreasing the dose but at a more gradual rate (see DOSAGE AND ADMINISTRATION [ 2.7 ] ).

5.11 Abnormal Bleeding SSRIs and SNRIs, including fluvoxamine maleate extended-release capsules, may increase the risk of bleeding events. Concomitant use of aspirin, nonsteroidal anti-inflammatory drugs, warfarin, and other anticoagulants may add to this risk. Case reports and epidemiological studies (case-control and cohort design) have demonstrated an association between use of drugs that interfere with serotonin reuptake and the occurrence of gastrointestinal bleeding.Based on data from the published observational studies, exposure to SSRIs, particularly in the month before delivery, has been associated with a less than 2-fold increase in the risk of postpartum hemorrhage <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 ) ]</span>. Bleeding events related to SSRIs and SNRIs use have ranged from ecchymoses, hematomas, epistaxis, and petechiae to life-threatening hemorrhages. Patients should be cautioned about the increased risk of bleeding associated with the concomitant use of fluvoxamine maleate extended-release capsules and NSAIDs, aspirin, or other drugs that affect coagulation (see WARNINGS AND PRECAUTIONS [ 5.9 ] ).

5.12 Activation of Mania/Hypomania During premarketing studies of immediate-release fluvoxamine maleate tablets involving primarily depressed patients, hypomania or mania occurred in approximately 1% of patients treated with fluvoxamine. In a 10-week pediatric OCD study, 2 out of 57 patients (4%) treated with fluvoxamine experienced manic reactions, compared to none of 63 placebo patients. Activation of mania/hypomania has also been reported in a small proportion of patients with major affective disorder who were treated with other marketed antidepressants. As with all antidepressants, fluvoxamine maleate extended-release capsules should be used cautiously in patients with a history of mania.

5.13 Seizures During premarketing studies with immediate-release fluvoxamine maleate tablets, seizures were reported in 0.2% of fluvoxamine-treated patients. Caution is recommended when the drug is administered to patients with a history of convulsive disorders. Fluvoxamine should be avoided in patients with unstable epilepsy, and patients with controlled epilepsy should be carefully monitored. Treatment with fluvoxamine should be discontinued if seizures occur or if seizure frequency increases.

5.14 Hyponatremia Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including fluvoxamine maleate extended-release capsules. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Cases with serum sodium lower than 110 mmol/L have been reported. Elderly patients may be at greater risk of developing hyponatremia with SSRIs and SNRIs (see USE IN SPECIFIC POPULATIONS, Geriatric Use [ 8.5 ] ). Also, patients taking diuretics or who are otherwise volume depleted may be at greater risk. Discontinuation of fluvoxamine maleate extended-release capsules should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted. Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls. Signs and symptoms associated with more severe and/or acute cases have included hallucination, syncope, seizure, coma, respiratory arrest, and death.

5.15 Use in Patients with Concomitant Illness Closely monitored clinical experience with fluvoxamine maleate extended-release capsules in patients with concomitant systemic illness is limited. Caution is advised in administering fluvoxamine maleate extended-release capsules to patients with diseases or conditions that could affect hemodynamic responses or metabolism. Fluvoxamine maleate extended-release capsules or immediate-release fluvoxamine maleate tablets have not been evaluated or used to any appreciable extent in patients with a recent history of myocardial infarction or unstable heart disease. Patients with these diagnoses were systematically excluded from many clinical studies during premarketing testing of these products. Evaluation of the electrocardiograms for patients with depression or OCD who participated in premarketing studies revealed no differences between fluvoxamine and placebo in the emergence of clinically important ECG changes. Patients with Hepatic Impairment - In patients with liver dysfunction, following administration of immediate-release fluvoxamine maleate tablets, fluvoxamine clearance was decreased by approximately 30%. Patients with liver dysfunction should begin with a low dose of fluvoxamine maleate extended-release capsules and increase it slowly with careful monitoring.

5.16 Laboratory Tests There are no specific laboratory tests recommended.

5.17 Sexual Dysfunction Use of SSRIs, including fluvoxamine maleate extended-release capsules, may cause symptoms of sexual dysfunction (see ADVERSE REACTIONS [6.1 ] ) . In male patients, SSRI use may result in ejaculatory delay or failure, decreased libido, and erectile dysfunction. In female patients, SSRI use may result in decreased libido and delayed or absent orgasm. It is important for prescribers to inquire about sexual function prior to initiation of fluvoxamine maleate extended-release capsules and to inquire specifically about changes in sexual function during treatment, because sexual function may not be spontaneously reported. When evaluating changes in sexual function, obtaining a detailed history (including timing of symptom onset) is important because sexual symptoms may have other causes, including the underlying psychiatric disorder. Discuss potential management strategies to support patients in making informed decisions about treatment.