R. M. Finder, R. N. Brogden, T. Speight
2012
Citations
2
Influential Citations
22
Citations
Quality indicators
Journal
Drugs
Abstract
SummaryViloxazine1, 2-(2-ethoxyphenoxymethyl)-2,3,5,6-tetrahydro-1, 4-oxazine, is structurally distinct from conventional tri- or tetra-cyclic antidepressants. In contrast to imipramine, it has minimal sedative anticholinergic or adrenergic effects in man; it acts in part like an amphetamine-type central stimulant though there is little evidence of dependence or non-durability of drug effects. Viloxazine is indicated for use in the treatment of all types of depression, and may be especially useful in the elderly if they have no history of proneness to nausea or if they have a tendency to delirium.Viloxazine is rapidly and almost completely absorbed following oral administration. Unchanged drug is the major component in blood at all times and it is probably the pharmacologically active moiety. It has a short plasma half-life and is extensively metabolised and rapidly eliminated in the urine.Controlled trials in hospital inpatients, outpatients attending hospital clinics, and in depressed patients in general practice, have generally failed to find a significant difference between the antidepressant effects of viloxazine and imipramine. Viloxazine produces significant improvement in about two-thirds of patients but no attempt has usually been made to relate response to the type of depression. Only a minority of trials have suggested that viloxazine is more rapid in its action than imipramine or amitriptyline, and none has indicated that viloxazine has any advantage in terms of alleviation of anxiety or other symptoms often associated with depression. In a controlled trial in depressive patients with a clear anxiety component, viloxazine alone was preferable to a combination of viloxazine with perphenazine or diazepam, because the combination did not produce an enhanced therapeutic effect and the incidence of side-effects was possibly increased. Some other trials have included the routine use of an anxiolytic or minor tranquilliser.Withdrawals due to side-effects have been similar with viloxazine and imipramine, but most controlled trials have found a significant advantage for viloxazine in terms of the overall incidence of side-effects. Controlled comparisons have not been made with other antidepressants also claimed to have fewer unwanted effects. In general, viloxazine is well tolerated, and there have been no reports of major toxicity during short- or long-term studies. Anticholinergic-like effects and sedation have been less marked and less persistent than those of imipramine, but nausea and vomiting have been common complaints and appear to be dose-related.Viloxazine is usually given in oral doses of 50 to 100mg, 3 times daily. Higher doses, up to 400mg daily, have been used, but nausea and vomiting may be more frequent. Twice-daily dosage of 100mg (morning and noon) may offer some advantage in efficacy, and the severity of side-effects may be minimised by beginning treatment with 100 to 150mg daily for a few days.