You should follow your doctor's advice when using Zyban.
Once you've bought the Zyban, you should set a quit date. This date should be in week two of your treatment. Continue smoking as normal in the first week of treatment, because it takes about one week for bupropion to start working properly.
Not smoking at all after your quit date gives you the best chance of stopping for good. If you slip up and have a cigarette after your quit date, you may still succeed at quitting if you keep taking your course of Zyban and recommit to stopping smoking.
Your doctor will tell you how many tablets you should take. The usual dose is one tablet in the morning for the first three days, then two tablets per day for the rest of the treatment. Tablets must be taken at least eight hours apart; one in the morning and the second in the evening. However, your doctor might decide to reduce the number of tablets you take. No-one should take more than two tablets per day. Usually treatment lasts for at least seven weeks.
If you miss a tablet by a few hours, you should just skip the dose you missed, and take one tablet at your next usual time. Never take more than one tablet of Zyban in an eight hour period.
Tablets should be swallowed whole - do not crush, break or chew the tablets (this releases the medicine too quickly and increases your risk of side effects). They can be taken with or without food. It is best not to drink alcohol while using Zyban. If you drink a lot of alcohol or suddenly stop drinking heavily, you may increase your chance of seizure.
There is no clear evidence that taking Zyban while using a nicotine replacement product would increase your chance of quitting compared to taking either product by itself.