A researcher has a timeworn message for smokers who use medication to help them quit: if at first you don't succeed, try, try again.

Reuters reported Feb. 24 that medications like Chantix (varenicline) and Zyban (bupropion) can be effective even if they don't result in abstinence during the first few weeks. David Gonzales, director of the smoking-cessation program at Oregon Health & Science University, said that it can take that long for many smokers to wean themselves off tobacco.

"If smokers on medication don't quit in the first week or two following their target quit date, clinicians often will instruct their patients to discontinue their medication. Clinicians consider this a failed attempt," said Gonzales.

Gonzales' research showed that 24 percent of patients taking Chantix were able to quit right away, compared to 18 percent taking Zyban and 10 percent given a placebo. However, another 20 percent of those taking Chantix and 11 percent of the Zyban group were able to quit if they kept taking the drugs for three months.

Gonzales presented his work at a recent meeting of the Society for Research on Nicotine and Tobacco.