From the Guidelines

No, nicotine does not decrease nicotine levels.

Nicotine acts on the body by stimulating the cholinergic anti-inflammatory response, which can modulate the immune response and reduce systemic inflammation 1.
The activation of the α7 nAChR by nicotine suppresses nuclear factor-κB-dependent transcriptional events, leading to downregulation of cytokine production and an attenuated response to inflammatory triggers.

Nicotine has been shown to have anti-inflammatory effects in animal studies, including reducing lung vascular permeability and leukocyte infiltration in models of acute lung injury 1.
However, the effects of nicotine in humans are not well established, and its use is highly addictive and has several adverse cardiopulmonary effects.

The potential therapeutic use of nicotine-containing medications or nicotine replacement drugs at doses without strong cardiopulmonary effects and with little risk of addiction warrants further investigation 1.
Nicotine replacement therapy or drugs such as varenicline or cytisine may be considered as a step towards tobacco and nicotine use cessation in smokers with COVID-19, due to their potential anti-inflammatory effects.

From the FDA Drug Label

Use reduces withdrawal symptoms, including nicotine craving, associated with quitting smoking The FDA drug label does not answer the question.

The concept of reducing nicotine levels in cigarettes to make them less addictive has been explored in several studies 2, 3, 4.
Research suggests that reducing nicotine levels in cigarettes could lead to lower intake of nicotine and a lower level of nicotine dependence 2, 4.
A study found that gas chromatography experiments showed that nicotine levels in the brain decreased by 75% after 150 min, which may indicate that dopamine is more susceptible to lower levels of nicotine than other neurotransmitters 5.

Nicotine has been shown to increase the release and turnover of neurotransmitters such as dopamine, serotonin, and norepinephrine in brain areas involved in cognitive processes 5.
The increase in dopamine and its metabolites was found to be greater than the increase in other neurotransmitters, and this increase was potentiated by reuptake blockers 5.
The effects of nicotine on neurotransmitter levels were found to be shorter in duration for serotonin and norepinephrine compared to dopamine 5.

Nicotine is highly addictive and is primarily responsible for the maintenance of cigarette smoking 2, 6.
The role of nitric oxide in cigarette smoking and nicotine addiction has been explored, with findings suggesting that nitric oxide may contribute to the development of cigarette smoking and nicotine addiction 6.
Reducing the nicotine content in cigarettes may reduce nicotine absorption and make cigarettes less addictive 2, 3, 4.