There are one or two pharmaceuticals for quit-smoking treatment that are marginally effective - assuming that the only alternative is death since otherwise you certainly wouldn't want to mess with them otherwise - and only have around a 90% failure rate. Unfortunately they are the ones that are impossible to describe as safe since they have a significant risk for cardiac and psychotic events. They have side effects such as a 1 in 30 risk for heart attack, and have caused hundreds of suicides, some murders, and an uncountable number of violent psychotic events. So on balance they are unsafe and have marginal efficacy that is not worth the risk if there are better alternatives.
There are plenty of pharmaceuticals for quit-smoking treatment that are known to be safe, with rare incidence of significant health events. Unfortunately they have a failure rate of around 95% to 98% and are only double the effectiveness of a placebo, so 'effective' could not possibly be used to describe them.
There are absolutely no pharmaceutical interventions for smoking cessation that can be described by any honest person as 'safe and effective'. Anyone with medical knowledge who describes pharmaceutical interventions as "safe and effective" is an outright liar. A safe medicine but with chance of success little better than a placebo, or alternatively a chance of a heart attack / suicide / crazy episode but a marginal possibility of success does not equal 'safe and effective' and a medically-qualified person who says it does should have their license removed. Such persons are not fit to practice medicine and certainly not fit to give advice; unless medical licenses are issued for proficiency in being a financially-conflicted mercenary for hire or a complete ignoramus.