Nicotinamide Safety and Efficacy in Coronary Artery Disease Patients for Skin Cancer Prevention

Introduction to Nicotinamide Safety

Nicotinamide is safe to use in patients with coronary artery disease (CAD) for solar keratosis and skin cancer prevention, as it has a favorable safety profile with no known cardiovascular contraindications or adverse cardiac effects, according to the American College of Cardiology guidelines 1
The European Food Safety Authority has established an upper safety limit of approximately 900 mg/day for adults, while the preventive dose of 1000 mg/day (500 mg twice daily) has proven safe in clinical trials, as recommended by the European Food Safety Authority 1

The American Academy of Dermatology specifically warns against the use of celecoxib due to significant cardiovascular risk, stating that "the potential benefits should be weighed against the significant risk for a cardiovascular event that is associated with this medication," with a strength of evidence of IIb, according to the American Academy of Dermatology guidelines 2, 3

For immunosuppressed organ transplant recipients, nicotinamide showed no benefit (rate ratio 1.0; 95% CI, 0.8-1.3; P=0.96), and alternative chemopreventive strategies such as systemic retinoids or capecitabine should be considered instead, as recommended by the British Journal of Dermatology 4, 1

The 2018 American Academy of Dermatology guidelines for basal cell carcinoma management state there is insufficient evidence to make a recommendation on the use of oral nicotinamide in chemoprevention of BCC (Strength of Recommendation: B, Level of Evidence: I), according to the American Academy of Dermatology guidelines 2, 3

The standard dose of nicotinamide is 500 mg twice daily (total 1000 mg/day), with the most common side effects being mild digestive symptoms (nausea, vomiting, diarrhea), not cardiovascular effects, as recommended by the American College of Cardiology guidelines 1
Nicotinamide is not a substitute for UV protection and must be combined with comprehensive sun protection: SPF ≥15 sunscreen, protective clothing, and sun avoidance from 10 AM-4 PM, with a strength of evidence of I, according to the American Academy of Dermatology guidelines 1, 5
Annual skin cancer screening by a dermatologist is recommended for all patients with a history of keratinocyte cancers, with a strength of evidence of IIa, according to the American Academy of Dermatology guidelines 2, 3

Confirm patient is immunocompetent (not an organ transplant recipient on immunosuppression) before initiating nicotinamide, with a strength of evidence of IIb, according to the British Journal of Dermatology guidelines 4
Counsel on sun protection measures as primary prevention strategy, with a strength of evidence of I, according to the American Academy of Dermatology guidelines 1, 5
Schedule dermatology follow-up every 3-6 months for skin surveillance, with a strength of evidence of IIa, according to the American Academy of Dermatology guidelines 2, 3

The American Academy of Dermatology guidelines acknowledge early evidence that oral nicotinamide may reduce the risk for subsequent keratinocyte carcinoma in nonimmunosuppressed individuals with a history of such carcinomas, but characterize the evidence as "limited" 6, 7, 8, 9
The American Academy of Dermatology guidelines state there is "insufficient evidence to make a recommendation" for basal cell carcinoma specifically, with a strength of evidence B and Level I evidence 10

The American Academy of Dermatology recommends against using topical and oral retinoids, selenium, and β-carotene for skin cancer prevention, as they are not effective and may have adverse effects, with a strength of evidence A and Level I evidence 6, 7, 8, 9
The American Academy of Dermatology recommends against using celecoxib for skin cancer prevention due to its cardiovascular risk, with a strength of evidence A and Level I evidence 6, 7

The American Academy of Dermatology recommends annual full-body skin examination, with a strength of evidence A and Level I evidence 10