|
Page: Additional Warnings
Main article
| Home > Cancer > Additional Warnings |
May cause false-positive for amphetamine
Bupropion contains a similar pharmacological structure to that of amphetamines. In most cases prescription medications that contain bupropion (Wellbutrin, Zyban) will cause urinary drug tests to read a positive result in both amphetamines and occasionaly, methamphetamine categories. It is imperative that the patient receiving bupropion treatment inform any administrators and interpreters of drug use tests of this.
Abuse liability
In animal studies and small studies with persons having experience with the use of amphetamines or cocaine, bupropion caused drug-seeking behaviour (animal experiments) and was recognized as an amphetamine-like drug by humans. Dopamine reuptake inhibition is responsible for the euphoria promoted by Cocaine, and Norepinephrine reuptake inhibition is responsible for the energizing effects of Cocaine. Because of this, there has been concern and controversy regarding the abuse liability of bupropion. In a scale ranging from placebo on the lower side to amphetamine, it was given an intermediate score indicating moderate likelihood of abuse. The stimulant effect reliably produced in mice however, has not been reliably seen in humans. There are isolated reports of patients crushing and insufflating bupropion and increasing dosages to attain a cocaine-like stimulant effect; however this often results in seizures and other severe side effects. In clinical practice, bupropion has been shown that the dose required for significant abuse would cause seizures in most patients. Bupropion is the only dopamine reuptake inhibitor/enhancer not classified as a scheduled stimulant, since reliable euphoria is not produced by the drug in doses that do not commonly induce seizures. While abuse has not become a significant problem in clinical usage, the drug should be given with caution to patients with a history of drug or alcohol abuse or dependence.
Chronic hepatotoxicity in animals
In rats receiving large doses of bupropion chronically, there was an increase in incidence of hepatic hyperplastic nodules and hepatocellular hypertrophy. In dogs receiving large doses of bupropion chronically, various histologic changes were seen in the liver, and laboratory tests suggesting mild hepatocellular injury were noted.
Use in pediatric patients
Bupropion has been shown to increase the incidence of suicidal thoughts and attempts in children and adolescents with depression. When treating major depressive disorder in this group of patients, clinical benefits should be weighed carefully against therapeutic hazards. Usually, bupropion is not indicated for pediatric patients under age 18.
Potential indications of bipolar and schizoaffective disorder
The effects of bupropion in treating eleven patients with bipolar or schizoaffective disorder were examined in an open trial. Most patients had been intolerant of or showed minimal to moderate improvement on lithium, neuroleptics, antidepressants, or a combination of these drugs. All patients were maintained on bupropion alone or bupropion in combination with low-dose neuroleptics or anxiolytics for one year or more, with little or no relapse and few side effects. Although these results are encouraging, additional larger studies need to be conducted to confirm this indication.
Alleged risks with certain treatments
In the UK, more than 7,000 reports of potential hazardous side effects have been collected. There have been 44 reports of suspected adverse reactions where there was a fatal outcome while taking Zyban. In reviewing these cases the MHRA stated that in the majority of cases the individual’s underlying condition may provide an alternative explanation. More than two thirds of reported deaths were from cardio-vascular or cerebro-vascular causes. A case-series analysis showed increased risk of seizure in the population taking bupropion, but no increase in the risk of sudden death. At least 107 cases of serious side effects have been reported in Germany.
In the UK, bupropion should only be prescribed as an aid in quitting smoking to smokers who have committed to a definite quit date and a prescription will not last more than 4 weeks after this target date. NICE has issued guidance to the effect that if the attempt to quit is unsuccessful the NHS will not provide funding for a further course, for at least 6 months.
In some countries, such as the UK, bupropion is approved only as a smoking cessation aid and not for treatment of depression.
Studies of juveniles with depression
A large study gathered the results of twenty-four studies of juveniles with depression. Patients were to take either a placebo (sugar pill) or an antidepressant (SSRIs and others, including bupropion) for one to four months. According to the results, nobody committed suicide in these studies, although two out of every hundred patients became suicidal on a placebo and four out of every hundred become suicidal on antidepressants. Results indicated that the risks of suicidal actions become high for some juveniles. These kinds of juveniles may include patients with:
* Bipolar illness, previously known as manic-depressive illness
* A family history of bipolar illness
* A personal or family history of attempting or committing suicide
|
Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
|