Combined therapy with a long acting form of NRT (such as the patch) and a shorter acting form (such as the gum) is a viable treatment for some smokers. If you are continuing to have cravings while on the patch, it is possible that such an approach would be appropriate for you. You should always discuss the use of more than one form of NRT with your doctor before starting combined therapy.
Source: Croghan G, Sloan J, Croghan I, Novotny P, Hurt R, DeKrey W, Mailliard J, Ebbert L, Swan D, Walsh D, Wiesenfeld M, Levitt R, Stella P, Johnson P, Tschetter L , Loprinzi C. Comparison of nicotine patch alone versus nicotine nasal spray alone versus a combination for treating smokers: A minimal intervention, randomized multicenter trial in a nonspecialized setting. Nicotine Tob Res 2003;5:181-187.