Management of Macrocytosis in Smokers
The primary treatment for macrocytosis caused by smoking is complete smoking cessation, which should be implemented using a combination of evidence-based pharmacotherapy and behavioral therapy. 1
Evaluation of Macrocytosis in Smokers
Before initiating treatment, a proper evaluation should include:
- Vitamin B12 level assessment
- Reticulocyte count
- Peripheral blood smear examination
- Liver function tests
- Assessment of alcohol use
- Medication review
Macrocytosis (mean corpuscular volume >100 fL) in smokers can be directly related to smoking itself, but it's important to rule out other common causes including:
- Alcohol use (most common cause in many populations) 2
- Vitamin B12 or folate deficiencies
- Medications (anticonvulsants, immunosuppressants)
- Liver disease
- Reticulocytosis from hemolysis or hemorrhage
- Myelodysplastic syndromes 3
Smoking Cessation Treatment Plan
Step 1: Pharmacotherapy (First-Line Options)
Combination Nicotine Replacement Therapy (NRT): Use of both a long-acting form (patch) plus a short-acting form (gum, lozenge, inhaler, or nasal spray) is more effective than monotherapy 1
Varenicline: More effective than single NRT products or bupropion alone, increasing abstinence rates from 12% to 28% compared to placebo 1
Bupropion SR: Increases abstinence rates from 11% to 19% compared to placebo, but should be avoided in patients with seizure disorders 1
Step 2: Behavioral Therapy
- Minimum of 4 sessions during each 12-week treatment course
- Total contact time of 90-300 minutes
- Focus on coping strategies for nicotine withdrawal symptoms
- Identify smoking triggers and address patient-specific barriers to quitting 1
Even brief advice (3 minutes) by healthcare providers is effective, but more intensive counseling yields better results 1.
Follow-up Protocol
- Initial follow-up assessment within 2-3 weeks of starting therapy
- Continued support throughout the duration of therapy (minimum 12 weeks)
- Additional follow-up at 6 and 12 months 1
- Monitor MCV values to track improvement after smoking cessation
Managing Relapse
Smoking is a chronic relapsing disorder, and patients may slip or relapse. This should be expected and managed with continued support and treatment adjustments as needed 4. Do not view smoking slips as a failure requiring an alternative method - it may take more than one quit attempt with the same therapy to achieve long-term cessation 4.
Special Considerations
- Smoking cessation should be offered regardless of cancer status or prognosis, as it improves cancer treatment outcomes, reduces disease recurrence, and decreases secondary cancers 4
- Smoking increases all-cause mortality, cancer-specific mortality, and treatment-related toxicity 1
- Avoid e-cigarettes as an alternative to conventional cigarettes as they are not harm-free 4
- Patients should also be encouraged to discontinue use of all combustible products (cigars, hookah, marijuana) and smokeless tobacco products 4
Common Pitfalls to Avoid
- Using monotherapy instead of combination therapy
- Providing insufficient behavioral support
- Premature discontinuation due to minor side effects
- Failing to address smoking relapse 1
- Not recognizing that smoking cessation may unmask vitamin B12 deficiency that requires treatment
By implementing this comprehensive approach to smoking cessation, macrocytosis related to smoking can be effectively managed, leading to improved overall health outcomes and reduced mortality risk.