Nicorandil: from ulcer to fistula into adjacent organs

Nicorandil-induced colovesical fistula in a patient with diverticular disease

Nicorandil's adverse effects can cause severe patient morbidity and can present to any specialty. Those with underlying diverticular disease are most susceptible. Medication reviews are vital for patients presenting with ulcer or fistula symptoms.

Genetic Risk of Diverticular Disease Predicts Early Stoppage of Nicorandil

Gastrointestinal fistulation has been widely reported as an adverse effect of nicorandil therapy in Europe. People who have underlying diverticular disease are most at risk of this side effect. In Western countries, diverticular disease is highly prevalent and can be clinically silent. This study aimed to identify diverticular disease genetic risk scores (GRSs) associated with early nicorandil stoppage, a surrogate marker for drug intolerance. A case-control study was carried out on 1,077 patients from the Genetics of Diabetes Audit and Research Tayside Scotland (GoDARTS) database. Cases were defined as having < 9 nicorandil prescriptions with no identifiable reason for stopping (n = 230). Controls had either ≥ 9 prescriptions, treatment continuation to death/study end or stoppage post-myocardial infarction. Two diverticular GRSs were created and used in logistic regression models. Isosorbide mononitrate was used as a control analysis. Patients with a raised diverticular GRS, based on 23 replicable loci, had increased risk of stopping nicorandil therapy early (univariate (odds ratio (OR) 2.26; P = 0.04], multivariate (OR 3.96; P = 0.01)). Similar trends were noted when using the full 42 variant diverticular score but statistical significance was not reached. The isosorbide control analysis did not reach statistical significance. Our analysis demonstrates a novel positive association between a raised diverticular GRS and early stoppage of nicorandil therapy.

Nicorandil, Gastrointestinal Adverse Drug Reactions and Ulcerations: A Systematic Review

INTRODUCTION

Nicorandil is a popular anti-anginal drug in Europe and Japan. Apart from some common adverse drug reactions (ADR), its safety is satisfactory. Several reports have suggested a link between nicorandil, gastrointestinal (GI) ulceration and fistulas. The review aims to critically appraise, synthesize and present the available evidence of all known GI ADR per anatomical location.

METHODS

The study complied with the PRISMA statement. Literature and pharmacovigilance databases were used to provide rate and/or calculate parameters (median age, median dose, history of symptoms, length of therapy and healing time after withdrawal of the drug). Differences in distribution of quantitative variables were analyzed via Mann-Whitney test. Correlation between quantitative variables was assessed with a Spearman's correlation coefficient. A p value <0.05 was significant.

RESULTS

Oral ulcerations occur in 0.2% of the subjects, anal ulcerations are present between 0.07% and 0.37% of patients. Oral and distal GI involvements are the most common ADR (28-29% and 27-31% of all GI ADR, respectively). The hepatobiliary system, the pancreas and salivary glands are not affected by nicorandil exposure. The time to develop oral ulcerations is 74 weeks among people on <30 mg/day compared to only 7.5 weeks in individuals on higher regimens (p = 0.47). There is a significant correlation between dose and ulcer healing time (Spearman's 0.525, p < 0.001).

CONCLUSIONS

Ulcerative disease is a very commonly reported GI ADR. A delayed ulcerative tendency supports the hypothesis of an ulcerogenic metabolite. Nicorandil seems to act as a cause of the ulcerations, but appears to also work in synergy with other promoting factors. Whether the action of the metabolites relies on a specific mechanism or a simple chemical ulceration is still to be established.

Role of nicotinic acid and nicotinamide in nicorandil-induced ulcerations: from hypothesis to demonstration

Nicorandil, a nicotinamide ester, was first reported to be involved in the induction of oral ulcers in 1997. Since then, many reports of single or multiple nicorandil-induced ulcerations (NIUs) have been reported. We hypothesised that in the case of high-dosage nicorandil or after an increased dosage of nicorandil, nicotinic acid and nicotinamide (two main metabolites of nicorandil) cannot appropriately merge into the endogenous pool of nicotinamide adenine dinucleotide/phosphate, which leads to abnormal distribution of these metabolites in the body. In recent or maintained trauma, nicotinamide increases blood flow at the edge of the raw area, inducing epithelial proliferation, while nicotinic acid ulcerates this epithelial formation, ultimately flooding the entire scar. We demonstrate, by comparison to a control patient non-exposed to nicorandil, an abnormal amount of nicotinic acid (×38) and nicotinamide (×11) in the ulcerated area in a patient with NIUs. All practitioners, especially geriatricians, dermatologists and surgeons, must be aware of these serious and insidious side effects of nicorandil. It is critical to rapidly reassess the risk-benefit ratio of this drug for any patient, and not only for those with diverticular diseases.

A case of nicorandil-induced unilateral corneal ulceration

Nicorandil, a second-generation nitro derivative, has been reported to induce single or multiple ulcerations in many locations, including oral, anal, perianal, vulvovaginal, perivulval, penile, gastrointestinal, colic, peristomal and skin locations. Ocular locations are now highly suspected. Herein, we report the case of a 78-year-old woman who experienced corneal ulceration at second cataract surgery (right eye) while being treated with nicorandil for 3 years. Four years before, she had had an uneventful first cataract surgery (left eye). The ulcers healed within 6 weeks after simple withdrawal of nicorandil, an expected delay for this type of chemical ulcer. The substitution of nicorandil with classic nitric oxide donors has already been done without complication. Surgical intervention is unnecessary and inappropriate. Case reports of ocular side effects induced by nicorandil are rare and probably underestimated.