This may be seen as a way of 'hedging your bets' but it is not recommended by the manufacturers. If combined in an inappropriate and excessive fashion the user may place themselves at risk, however small, of nicotine overdose. It is possible, though, that a medical professional may recommend that patches be used in combination with the gum or the inhaler but this would be only be relevant to that specific case. Sometimes such 'nicotine rescue' techniques are used target a particular time of the day when the smoker experiences strong nicotine withdrawal. They may need to supplement a steady form of NRT, like the patch, with a more immediate form of NRT, like the gum, in order to stop a relapse into smoking. Use of another NRT is preferable to even one cigarette that can commonly result in a return to the smoking habit.