August 06, 2007

Quitting Tobacco: An Easy Way For The Blind To Go!

Its really hard to quit smoking. So much so, that its quitting has been compared to that of cocaine or even heroin. First and foremost, a resolute and firm mental preparation is required. Once a decision has been made, it can be set forth into action. However, there are certain drugs which make quitting easier. For example, nicotine may be supplemented as a gum, nasal spray or as a dermal patch, so that a small amount of it will be released and weaning off may be easier (guess you remember, fight fire with fire).

Apart from that, clonidine, bupropion, varenicline (Chantix) and many other drugs have been tried. Bupropion (Wellbutrin, Zyban) is a dopamine and norepinephrine reuptake inhibitor (DNRI). Dopamine, the reward chemical, and norepinephrine are secreted by nerve terminals in the brain. They then exert their effects, till they are metabolized or they are recalled back (reuptake) to the originating cells. Thus, actions cease once they are uptaken by the secreting cells themselves. Bupropion, by preventing their (dopamine and nor-epinephrine) reuptake, lets them remain in the synapse for alonger time, thereby making the person feel the high, even while they are not on tobacco. Varenicline, on the other hand, acts as a partial agonist at nACh (nicotinic acetyl cholinergic) receptors. A partial agonist is one substance (ligand) that can bind with a receptor and can elicit an action, though milder. Thus when varenicline is given, it stimulates the same nACh receptor that nicotine of tobacco smoke used to bind and stimulate. Thus, the craze for the crazy puff is gone. But, no matter what therapy you are on, as long as you are resolute, you can win, and nothing else matters!!

Recently, a vaccine is being developed that would bind nicotine and thus will not allow nicotine to bind to the nicotinic receptors. This is expected to wean away smokers since they will no longer be able to get the 'kick'. Normally a vaccine is given to boost immunity to pathogens. Here however its properties will be exploited for another noble purpose.

N.B. Recently (July 1, 2009) the US Food and Drug Administration (FDA) has announced that bupropion and varenicline manufacturers must carry a 'boxed warning' in their labels, that use of these drugs has been associated with serious neuropsychiatric events. They can cause symptoms ranging from mood changes to suicidal tendencies, hostilities and agitation. Whether they were the effects of nicotine withdrwal or the effects of the drugs themselves were not clear.

However, the site concluded with the following advice: "Any adverse events associated with varenicline or bupropion should be communicated to the FDA's MedWatch reporting program by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at http://www.fda.gov/medwatch, or by mail to 5600 Fishers Lane, Rockville, Maryland 20852-9787."

Last updated: 2nd July 2009
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