Combination Nicotine Replacement Therapy

The FDA has not approved a combination NRT strategy for treatment of smoking cessation
(Fiore et al., 2000). The Public Health Service Guideline recommends an effective combination of NRT that has produced higher long-term abstinence rates than only one type of NRT.

The combination NRT found effective involves (1) passive dosing (nicotine patch) that produces relatively steady levels of drug in the body, while the (2) second type (either the nicotine gum or nicotine nasal spray) should permit dosing as needed allowing the user to adjust the dose
(Fiore et al., 2000).

Precautions

Before advising tobacco users to quit with combination NRT, review the Treatment Specialist's role.  There is relatively little safety data on the conjoint use of NRTs (Fiore et al., 2000). Combination NRT could increase the risk of nicotine overdose and the Public Health Service Guideline reccomends that it be used only with those people unable to quit using a single type of pharmacotherapy
(Fiore et al., 2000).

However, for a heavily addicted tobacco user who has not been successful in quitting with single drug therapy, some research suggests that use of the nicotine patch plus a short acting form of NRT in addition to bupropion may be prescribed; the risk of adverse affects versus potential benefits must be evaluated by the clinician (Schroeder, 2005).

Cost

Combination NRT is more expensive than single NRT.
 

New Therapies on the Horizon

Several new cessation medications have begun to be tested, but as of  2007 have not been approved by the FDA.

• Rimonobant is a drug that has been studied for treatment of smoking and obesity; this drug targets the endocannabinoid system in the brain
  (Peck n.d., Midlands Therapeutics Review and Advisory Committee (MTRAC) 2006, National Prescribing Center(NPC) 2007). 
    
• Vaccines have been developed that produce antibodies to nicotine and reduce nicotine levels in the body of a tobacco user; however the long-term effects on cessation have not been demonstrated (Schroeder 2005).
   
• Other clinical trials have investigated cytochrome P246 inhibitors which affect metabolism of nicotine in the liver, giving the smoker more nicotine per cigarette; these drugs may have potential use for smokers who are not ready to quit (contemplative stage) or are trying to increase the potency of NRT during a quit attempt (Schroeder 2005).
    

Not Recommended Pharmacotherapy

Antidepressants other than Bupropion SR and Nortriptyline

• There is insufficient data.
• No published articles met selection criteria for review.
• Other antidepressants under investigation include other tricyclics and selective serotonin re-uptake inhibitors (SSRIs).

Anxiolytics / Benzodiazepines / Beta-blockers

• There is insufficient data.
• A few trials have investigated propranolol and diazepam. Both reveal no beneficial effects for smoking cessation.
• Buspirone is under investigation.

Silver Acetate

• There is no proven beneficial effect of silver acetate for smoking cessation.

Mecamylamine

• There is no proven beneficial effect of mecamylamine alone for smoking cessation.
• Mecamylamine and the nicotine patch is under investigation.