Gene polymorphism in amlodipine induced gingival hyperplasia: a case report

Large Anterior Oronasal Fistula Repair Using Pedicled Buccal Fat Pad and Fibroepithelial Tissue

Oronasal fistula (ONF) is the most common complication after palatoplasty in patients with cleft lip and palate (CLP). When left untreated, it may negatively affect the quality of life, leading to development of other comorbidities. This study reports for the first time, the use of a portion of a hyperplasic tissue associated with pedicled buccal fat pad flap to repair a large anterior ONF in a 60-year-old man. The hyperplasic tissue may have developed due to the combination of a loose fitting upper denture and long-term use of dihydropyridine calcium channel blocker (amlodipine besylate). There is controversy in the literature about use of pedicled buccal fat pad flap in the anterior region. However, in this study, we report successful repair of a large anterior ONF using a portion of a fibroepithelial hyperplasic tissue associated with pedicled buccal fat pad flap.

Allele-specific polymerase chain reaction for the detection of single nucleotide polymorphism in amlodipine-induced gingival enlargement

WHAT IS KNOWN AND OBJECTIVE

Studies indicate that there is an increased serum concentration of amlodipine (a calcium channel blocker used to treat hypertension and angina) in patients having mutant multidrug resistance 1 (MDR1) gene. Hence, genetic factors may play a very significant role in amlodipine-induced complications including gingival enlargement.

CASE DESCRIPTION

Three patients with amlodipine-induced gingival enlargement showed improvement following drug substitution of amlodipine with enalapril (an angiotensin-converting enzyme inhibitor) and non-invasive periodontal therapy. Using allele-specific polymerase chain reaction, single nucleotide polymorphism of MDR1 gene of heterozygous mutant type (CT genotype) was identified in all three cases.

WHAT IS NEW AND CONCLUSION

Drug-induced complications can potentially be a result of genetic factors, in combination with various local and systemic factors. Identifying genetic polymorphisms early might help predict adverse reactions and determine prognosis.

Drug-induced gingival overgrowth: A critical insight into case reports from over two decades

Drug-induced gingival overgrowth (DIGO) is a well-recognized adverse effect of certain systemic medications. Calcium channel blockers, anticonvulsants, and immunosuppressants are frequently implicated drugs in the etiology of DIGO. Drug variables, plaque-induced inflammation, and genetic factors are the three important factors in the expression of gingival changes after systemic medication use. Careful clinical examination and thorough history taking form the basis for diagnosis of DIGO. Histopathological examination is often neglected; however, it is an important aid that helps in differential diagnosis. Cessation or change of drug and meticulous plaque control often leads to regression of the lesion, which however might need surgical correction for optimal maintenance of gingival health. The purpose of the present article is to review case reports and case series published in the last two decades and to assimilate and compile the information for clinical applications such as diagnosis and therapeutic management of DIGO.

Multidrug resistance 1 gene polymorphism in amlodipine-induced gingival enlargement

Gingival enlargement comprises any clinical condition in which an increase in the size of the gingiva is observed. It is a side effect associated with some distinct classes of drugs, such as anticonvulsants, immunosuppressant, and calcium channel blockers. Among calcium channel blockers, nifedipine causes gingival enlargement in about 10% of patients, whereas the incidence of amlodipine, a third-generation calcium channel blocker, induced gingival enlargement is very limited. Because the calcium antagonists, albeit to a variable degree, act as inhibitors of P-glycoprotein (P-gp), the gene product of multidrug resistance 1 (MDR1), and inflammation may modify P-gp expression. We hereby, report a case of amlodipine-induced gingival enlargement with MDR1 3435C/T polymorphism, associated with inflammatory changes due to plaque accumulation, in a 50-year-old hypertensive male patient. The genotype obtained for the polymorphism was a heteromutant genotype, thus supporting the contention that the MDR1 polymorphism may alter the inflammatory response to the drug.

Drug-induced gingival overgrowth: the genetic dimension

Background:

Currently, the etiology of drug-induced gingival overgrowth is not entirely understood but is clearly multifactorial. Phenytoin, one of the common drugs implicated in gingival enlargement, is metabolized mainly by cytochrome P450 (CYP)2C9 and partly by CYP2C19. The CYP2C9 and CYP2C19 genes are polymorphically expressed and most of the variants result in decreased metabolism of the respective substrates.

Aims:

The present study was undertaken to investigate the influence of the CYP2C9*2 and *3 variant genotypes on phenytoin hydroxylation in subjects diagnosed with epilepsy from South India, thus establishing the genetic polymorphisms leading to its defective hydroxylation process.

Materials and Methods:

Fifteen epileptic subjects, age 9 to 60 years were included in the study. Among the study subjects, 8 were males and 7 were females. Genomic DNA was extracted from patients’ blood using Phenol-chloroform method and genotyping was done for CYP2C9 using customized TaqMan genotyping assays on a real time thermocycler, by allelic discrimination method. The genetic polymorphisms *1, *2 and *3 on CYP2C9 were selected based on their function and respective allele frequencies in Asian subcontinent among the Asian populations.

Results:

CYP2C9*1*2 and CYP2C9*3/*3 were identified with equal frequency in the study population. There were seven subjects with CYP2C9*1/*2 genotype (heterozygous mutant), one subject with CYP2C9*1/*1 (wild type) and seven study subjects with CYP2C9*3/*3 (homozygous mutant).

Conclusion:

The results obtained in the present study will be helpful in the medical prescription purposes of phenytoin, and a more personalized patient approach with its administration can be advocated.

Is periodontal health a predictor of drug-induced gingival overgrowth? A cross-sectional study

BACKGROUND

Gingival overgrowth is a common side-effect of amlodipine regimen on the oral cavity. There is controversy regarding the cause and effect relationship of periodontal health and drug induced gingival overgrowth. Therefore, this study was conducted to investigate and to assess the relationship between the periodontal health and the onset and severity of gingival overgrowth in hypertensive patients receiving amlodipine.

MATERIALS AND METHODS

A total of 99 known hypertensive patients on amlodipine regimen were included in this study. Probing pocket depth (PPD) and clinical attachment loss (CAL) were noted on four sites of maxillary and mandibular anterior teeth. Gingival enlargement scores were assessed for each patient by employing the hyperplastic index. Oral hygiene status was evaluated using the calculus index (CI). Patients were divided into H, E and L groups based on their periodontal status and responders and non-responders based on their hyperplastic index scores. Differences in means of different periodontal variables in different groups were tested for significance by using ANOVA and unpaired Student t-test. Pearson's correlation coefficient was calculated to assess the correlation between different variables. For all analyses, P < 0.05 was considered to be significant.

RESULTS

All the periodontal parameters were statistically highly significant (P = 0.00) amongst H, E and L groups and between responders and non-responders. Statistically highly significant Pearson correlation coefficients were found between mean PPD and mean hyperplastic score, mean CAL and mean hyperplastic score and mean calculus and mean hyperplastic score.

CONCLUSION

The results of this study indicated a definite association between periodontal health and development and severity of amlodipine-induced gingival overgrowth.