BUPROPION

 BUPROPION

BRAND NAME:- SMOQUIT 150mg tab .

BUPROPION is a inhibitors of DA and NA uptake has excitant rather than sedative property ,is an atypical antidepressant primarily used to treat major depressive disorder and to support smoking cessation. It is also popular as an add-on medication in the cases of "incomplete response" to the first-line selective serotonin reuptake inhibitor (SSRI) antidepressant .

PHARMACODYNAMIC:-

Bupropion is chemically unrelated to tricyclic, tetracyclic, selective serotonin re-uptake inhibitors, or other known antidepressant agents. Compared to classical tricyclic antidepressants, Bupropion is a relatively weak inhibitor of the neuronal uptake of norepinephrine and dopamine. In addition, Bupropion does not inhibit monoamine oxidase. Bupropion has been found to be essentially inactive at the serotonin transporter (SERT)(IC50 >10 000 nM),12 however both bupropion and its primary metabolite hydroxybupropion have been found to block the function of cation-selective serotonin type 3A receptors (5-HT3ARs).

Bupropion produces dose-related central nervous system (CNS) stimulant effects in animals, as evidenced by increased locomotor activity, increased rates of responding in various schedule-controlled operant behaviour tasks, and, at high doses, induction of mild stereotyped behaviour Label. Due to these stimulant effects and selective activity at dopamine and norepinephrine receptors, bupropion has been identified as having an abuse potential.Label,17 Bupropion has a similar structure to the controlled substance Cathinone, and has been identified as having mild amphetamine-like activity, particularly when inhaled or injected.

Bupropion is also known to lower the seizure threshold, making any pre-existing seizure conditions a contraindication to its use. This risk is exacerbated when bupropion is combined with other drugs or substances that lower the seizure threshold, such as cocaine, or in clinical situations that would increase the risk of a seizure such as abrupt alcohol or benzodiazepine withdrawal.Label As norepinephrine has been shown to have anticonvulsant properties, bupropion's inhibitory effects on NET are thought to contribute to its pro-convulsant activity. 

Bupropion has been shown to increase blood pressure and pose a risk for exacerbation of unmanaged or pre-existing hypertension,18,Label however, clinical trials of bupropion in smokers with CVD have not identified an increased incidence of CV events including stroke or heart attack.19 In clinical trials, the mean increase in systolic blood pressure associated with the use of bupropion was found to be 1.3 mmHg. 

MECHANISM OF ACTION:-

BUPROPION is three main metabolites (hydroxybupropion, threohydrobupropion , and  erythrohydrobupropion ) have significant central  noradrenergic  activity  at clinically  relevant doses. 

The mechanism of action is also uniquely defferent to other antidepressant . It enhances monoaminergic  neurotransmission not through binding to pre or post - synaptic serotonin respestor but by reducing the reuptake of  dopamine and norepinephrine .

• Bupropion is classed as a dual  norepinephrine and dopamine reuptake inhibitor (NDRI).

• Bupropion's activity increases intracellular dopamine and norepinephrine concentration in both the nucleus  accumbens and the prefrontal cortex.

•It has no affinity for post - synaptic histamine , alpha or beta adrenergic serotonin , dopamine acetylcholine respestors , differentiating it form most other antidepressant . 

USES:-

Bupropion is used to treat depression and prevent seasonal affective disorder (SAD). With SAD, people have episodes of depression that occur in the fall and winter.

Bupropion is also used to help people stop smoking. 

SIDE EFFECTS:-

Some common side effects:-

Insomnia (difficulty in sleeping), Headache, Nausea, Dryness in mouth, Agitation, Constipation, Weight loss, Tachycardia, Diaphoresis, Nasopharyngitis (inflammation of the throat and nasal passages), Blurred vision. 

SOME SERIOUS SIDE EFFECTS ARE:-

•High blood pressure (hypertension)

•Unusual thoughts or behaviors (hallucinations, paranoia, feeling confused.

DOSE:- 150-300mg Daily