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Dumirox (fluvoxamine maleate) is an antidepressant which functions pharmacologically as a selective serotonin reuptake inhibitor. Though it is in the same class as other SSRI drugs, it is most often used to treat obsessive-compulsive disorder.
Dumiorx potential interaction with Monoamine Oxidase Inhibitors
In patients receiving another serotonin reuptake inhibitor drug in combination with monoamine oxidase inhibitors (MAOI), there have been reports of serious, sometimes fatal, reactions including hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, and mental status changes that include extreme agitation progressing to delirium and coma. These reactions have also been reported in patients who have discontinued that drug and have been started on a MAOI. Therefore, it is recommended that Dumirox not be used in combination with MAOIs, or within 14 days of discontinuing treatment with a MAOI. After stopping Dumirox, at least 2 weeks should be allowed before starting a MAOI.
Dumiorx potential interaction with Terfenadine, Astemizole, and Cisapride
Terfenadine, astemizole and cisapride are all metabolized by the cytochrome P450IIIA4 isozyme, and it has been demonstrated that ketoconazole, a potent inhibitor of IIIA4, blocks the metabolism of these drugs, resulting in increased plasma concentrations of parent drug. Increased plasma concentrations of terfenadine, astemizole, and cisapride cause QT prolongation and have been associated with torsades de pointes-type ventricular tachycardia, sometimes fatal. Consequently, it is recommended that fluvoxamine not be used in combination with either terbinafine, astemizole, or cisapride.
Dumiorx potential interaction with other drugs:
Benzodiazepines: Benzodiazepines metabolized by hepatic oxidation (e.g., alprazolam, midazolam, triazolam elc.) 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: This interaction, which has not been investigated using higher doses of fluvoxamine, may be more pronounced if a 300 mg daily dose is co-administered, particularly since fluvoxamine exhibits non-linear pharmacokinetics over the dosage range 100-300 mg. If alprazolam is co-administered with Dumirox, the initial alprazolam dosage should be at least halved and titration to the lowest effective dose is recommended. No dosage adjustment is required for Dumirox.
Diazepam: The co-administration of Dumirox 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 co-administration.
Theophylline: If theophylline is co-administered with fluvoxamine maleate, its dose should be reduced to one third of the usual daily maintenance dose and plasma concentrations of theophylline should to monitored. No dosage adjustment is required for Dumirox.
Warfarin: Patients receiving oral anticoagulants and Dumirox should have their prothrombin time monitored and their anticoagulant dose adjusted accordingly. No dosage adjustment is required for Dumirox.
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