Detailed Drug Information:

DRUG CLASS AND MECHANISM: Bupropion is an antidepressantmedication that affects chemicals within the brain that nerves use to sendmessages to each other. These chemical messengers are calledneurotransmitters. The neurotransmitters that are released by nerves aretaken up again by the nerves that release them for reuse. (This isreferred to as reuptake.) Many experts believe that depression is causedby an imbalance among the amounts of neurotransmitters that are released.Bupropion is unrelated to other antidepressants. It works by inhibitingthe reuptake of dopamine, serotonin, and norepinephrine, an action whichresults in more dopamine, serotonin, and norepinephrine to transmitmessages to other nerves. Bupropion is unique in that its major effect ison dopamine, an effect which is not shared by the selective serotoninreuptake inhibitors or SSRIs (e.g. paroxetine, Paxil; fluoxetine, Prozac;sertraline, Zoloft) or the tricyclic antidepressants or TCAs (e.g.amitriptyline, Elavil; imipramine, Tofranil; desipramine, Norpramin).

PREPARATIONS: Wellbutrin, round tablets: 75 mg (orange), 100mg (red). Zyban, round tablets: 100 mg (blue), 150 mg (purple). Wellbutrin SR, round tablets: 100 mg (blue), 150 mg (purple). Wellbutrin XL, tablets: 150 and 300 mg.

STORAGE: Tablets should be kept at room temperature, 15-25°C(59-77°F).

PRESCRIBED FOR: Wellbutrin, Wellbutrin SR, and Wellbutrin XL are used for the management ofdepression. Zyban has been approved as an aid topatients who want to quit smoking.

DOSING: Bupropion usually is given in two or three daily doses.When used for smoking cessation, bupropion usually is started as 150 mgonce daily for three days, and then the dose is increased if the patienttolerates the starting dose. Smoking is discontinued two weeks afterstarting bupropion therapy. Wellbutrin SR is given as two daily doses. Wellbutrin XL is given as one dose daily.

DRUG INTERACTIONS: Although no systematic studies have been doneto assess the potential of bupropion to interact with other drugs,bupropion should be used cautiously in patients receiving drugs thatreduce the threshold for seizures. Such drugs include prochlorperazine(Compazine), chlorpromazine (Thorazine), and other antipsychoticmedications of the phenothiazine class. Additionally, persons who arewithdrawing from benzodiazepines (e.g. diazepam, Valium; alprazolam,Xanax) are at increased risk for seizures.

PREGNANCY: Although there are no adequate studies of bupropionin pregnant women, studies in pregnant animals using doses much higherthan those used in humans, have demonstrated that bupropion is safe.Bupropion, therefore, can be used in pregnancy if the physician feels thatit is necessary.

NURSING MOTHERS: It is not known if bupropion is secreted in breast milk.

SIDE EFFECTS: The most commonly noted side effects associatedwith bupropion are agitation, dry mouth, insomnia, headache, nausea,constipation, and tremor. In some people, the agitation or insomnia ismost marked shortly after starting therapy. Some patients may experienceweight loss. Uncommonly, patients may experience manic episodes orhallucinations. Four of every 1000 persons who receive bupropion in dosesless than 450 mg/day experience seizures. When doses exceed 450 mg/day,the risk increases ten-fold. Other risk factors for seizures include pastinjury to the head and medications which can lower the threshold forseizures. (See drug interactions.)

"If antidepressants are discontinued abruptly, symptoms may occur such as dizziness, headache, nausea, changes in mood, or changes in the sense of smell, taste, etc. (Such symptoms even may occur when even a few doses of antidepressant are missed.) Therefore, it is recommended that the dose of antidepressant be reduced gradually when therapy is discontinued."

It has been suggested that bupropion and SSRIs may cause depression to worsen and even lead to suicide in a small number of patients. These potential side effects are difficult to evaluate in depressed patients because depression can progress with or without treatment, and suicide is itself a consequence of depression. Moreover, the evidence supporting these potential side effects is weak. Therefore, no conclusions can yet be drawn about the relationship between bupropion and SSRIs and worsening depression and suicide. Until better information is available, patients receiving bupropion or SSRIs should be monitored for worsening depression and suicidal tendencies.