Bupropion

What is/are Zyban?

BUPROPION is used to help people quit smoking. This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care providers before I take this medicine?

They need to know if you have any of these conditions:

an eating disorder, such as anorexia or bulimia bipolar disorder or psychosis diabetes or high blood sugar, treated with medication head injury or brain tumor heart disease, previous heart attack, or irregular heart beat high blood pressure kidney or liver disease seizures suicidal thoughts or a previous suicide attempt Tourette's syndrome weight loss an unusual or allergic reaction to bupropion, other medicines, foods, dyes, or preservatives breast-feeding pregnant or trying to become pregnant

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. Do not cut, crush or chew this medicine. Take your medicine at regular intervals. If you take this medicine more than once a day, take your second dose at least 8 hours after you take your first dose. To limit difficulty in sleeping, avoid taking this medicine at bedtime. Do not take your medicine more often than directed. If you have been taking this medicine for some time, do not suddenly stop taking it. If your doctor wants you to stop the medicine, the dose will be slowly lowered over time to avoid any side effects.

A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

Note: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, skip the missed dose and take your next tablet at the regular time. There should be at least 8 hours between doses. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following:

medicines called MAO Inhibitors like Nardil, Parnate, Marplan, Eldepryl other medicines that contain bupropion like Zyban procarbazine

This medicine may also interact with the following:

amantadine carbamazepine cimetidine corticosteroids cyclophosphamide efavirenz levodopa or combination drugs containing levodopa linezolid medicines or herbal products for weight control or appetite medicines for mental depression, emotional, or psychotic disturbances nelfinavir nicotine orphenadrine phenobarbital phenytoin ritonavir some medicines for heart rhythm or blood pressure theophylline thiotepa tramadol warfarin

This list may not describe all possible interactions. Give your health care providers a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What side effects may I notice from this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:

allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue breathing problems changes in vision confusion fast or irregular heartbeat hallucinations increased blood pressure redness, blistering, peeling or loosening of the skin, including inside the mouth seizures suicidal thoughts or other mood changes unusually weak or tired vomiting

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

change in sex drive or performance constipation headache loss of appetite nausea tremors weight loss

This list may not describe all possible side effects.

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular checks on your progress. You may have to take this medicine for several days before you start to feel better.

Patients and their families should watch out for depression or thoughts of suicide that get worse. Also watch out for sudden or severe changes in feelings such as feeling anxious, agitated, panicky, irritable, hostile, aggressive, impulsive, severely restless, overly excited and hyperactive, or not being able to sleep. If this happens, especially at the beginning of treatment or after a change in dose, call your doctor.

Alcohol may increase dizziness or drowsiness. Avoid alcoholic drinks while taking this medicine. Drinking excessive alcoholic beverages, using sleeping or anxiety medicines, or quickly stopping the use of these agents while taking this medicine may increase your risk for a seizure.

You may get dizzy or have blurred vision. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells.

Your mouth may get dry. Chewing sugarless gum or sucking hard candy, and drinking plenty of water may help. Contact your doctor if the problem does not go away or is severe.

Do not treat yourself for coughs, colds, or allergies without asking your doctor or health care professional. Also do not take any herbal or non-prescription medicines for weight loss without the advice of your doctor or health care professional. Some ingredients may increase possible side effects.

Do not use nicotine patches or chewing gum without the advice of your doctor or health care professional while taking this medicine. You may need to have your blood pressure taken regularly if your doctor recommends that you use both nicotine and this medicine together.

Where should I keep this medicine?

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.

Mechanism of action

Bupropion affects a number of neurotransmitter systems, and its mechanisms of action are only partly understood. It is a dopamine reuptake inhibitor and releaser, and also a norepinephrine reuptake inhibitor and releaser. It is about twice as potent an inhibitor of dopamine reuptake as of norepinephrine reuptake.

As bupropion is rapidly converted in the body into several metabolites with differing activity, its action cannot be understood without reference to its metabolism. The occupancy of dopamine transporter (DAT) sites by bupropion and its metabolites in the human brain as measured by positron emission tomography was 6–22% in an independent study and 12–35% according to GlaxoSmithKline researchers. Based on analogy with serotonin reuptake inhibitors, higher than 50% inhibition of DAT would be needed for the dopamine reuptake mechanism to be a major mechanism of the drug's action. By contrast, approximately 65% occupancy or greater of DAT is required to achieve euphoria and reach abuse potential. However recent research indicates that dopamine is inactivated by norepinephrine reuptake in the frontal cortex, which largely lacks dopamine transporters, therefore bupropion can increase dopamine neurotransmission in this part of the brain, and this may be one possible explanation for any additional dopaminergic effects.

Bupropion has also been shown to act as a noncompetitive nicotinic antagonist.

Outside the nervous system, both bupropion and its primary metabolite hydrobupropion act in the liver as potent inhibitors of the enzyme CYP2D6, which metabolizes not only bupropion itself but also a variety of other drugs and biologically active substances. This mechanism creates the potential for a variety of drug interactions.

Adverse effects

Epileptic seizures are the most important adverse effect of bupropion. A high incidence of seizures was responsible for the temporary withdrawal of the drug from the market between 1986 and 1989. The risk of seizure is strongly dose-dependent, but also dependent on the preparation. The sustained-release preparation is associated with a seizure incidence of 0.1% at daily dosages of less than 300 mg of bupropion and 0.4% at 300–400 mg. The immediate release preparation is associated with a seizure incidence of 0.4% for dosages below 450 mg; the incidence climbs to 5% for dosages between 450–600 mg per day. For comparison, the incidence of unprovoked seizure in the general population is 0.07 to 0.09%, and the risk of seizure for a variety of other antidepressants is generally between 0 and 0.6% at recommended dosage levels.[30] Given that clinical depression itself has been reported to increase the occurrence of seizures, it has been suggested that low to moderate doses of antidepressants, including bupropion, may not actually increase seizure risk at all.

The prescribing information notes that hypertension, sometimes severe, was observed in some patients, both with and without pre-existing hypertension. The frequency of this adverse effect was under 1% and not significantly higher than found with placebo. A review of the available data carried out in 2008 indicated that bupropion is safe to use in patients with a variety of serious cardiac conditions.

In the UK, more than 7,600 reports of suspected adverse reactions were collected in the first two years after bupropion's approval by the Medicines and Healthcare Products Regulatory Agency as part of the Yellow Card Scheme, which monitored side effects. Approximately 540,000 people were treated with bupropion for smoking cessation during that period. The MHRA received 60 reports of "suspected adverse reactions to Zyban which had a fatal outcome". The agency concluded that "in the majority of cases the individual's underlying condition may provide an alternative explanation." This is consistent with a large, 9,300-patient safety study that showed that the mortality of smokers taking bupropion is not higher than the natural mortality of smokers of the same age.

The most common adverse effects associated with 12-hour sustained-release bupropion are reported to be dry mouth, nausea, insomnia, tremor, excessive sweating and tinnitus. Those that most often resulted in interruption of the treatment were rash (2.4%) and nausea (0.8%).

This article uses material from the Wikipedia article Bupropion, which is released under the Creative Commons Attribution-Share-Alike License 3.0.