<unk>  use for tobacco cessation has few contraindications. It is<unk> ot known whether<unk>  replacement therapy is effective for smoking cessation in adolescents, as of 2014. It is therefore<unk> ot recommended to adolescents. It is<unk> ot safe to use<unk>  during pregnancy or breastfeeding, although it is safer than smoking; the desirability of<unk> RT use in pregnancy is therefore debated. Randomized trials and observational studies of<unk>  replacement therapy in cardiovascular patients show<unk> o increase in adverse cardiovascular events compared to those treated with placebo. Using<unk>  products during cancer treatment is counterrecommended, as<unk>  promotes tumour growth, but temporary use of<unk> RTs to quit smoking may be advised for harm reduction.<unk>  gum is contraindicated in individuals with temporomandibular joint disease. People with chronic<unk> asal disorders and severe reactive airway disease require additional precautions when using<unk> <unk> asal sprays.<unk>  in any form is contraindicated in individuals with a known hypersensitivity to<unk> .
Nicotine
Heroin
Cannabis 
Cannabis
Cocaine
Cocaine 
Benzyl alcohol
Methamphetamine