Comment on "Efficacy of azithromycin in the treatment of cyclosporine-induced gingival hyperplasia in renal transplant recipients" by Nash and Zaltzman

Comparison of Azithromycin and Oral Hygiene Program in the Treatment of Cyclosporine-Induced Gingival Hyperplasia

BACKGROUND

It has been shown that azithromycin improves cyclosporine-induced gingival hyperplasia (GH), but its efficacy was never compared against an efficient oral hygiene program (OHP). The aim of this study was to analyze the effects of azithromycin plus OHP versus OHP alone in patients with cyclosporine-induced GH.

METHODS

After periodontal evaluation, 20 renal transplant recipients received detailed oral hygiene instructions and a complete OHP, and were randomized to control (OHP) or azithromycin groups (OHP plus azithromycin). Patients were re-evaluated after 15 and 30 days. Both groups were similar in time after transplant, age, gender, cyclosporine dose, and cyclosporine through level and serum creatinine. The control group had fewer patients using calcium cannel blockers (10% vs. 70%, p = 0.02).

RESULTS

All patients improved in pain, halitosis, and gum bleeding after OHP. The control group did not improve plaque index (PI) or GH. In contrast, baseline PI decreased from 1.52 +/- 0.28 to 0.50 +/- 0.16 on day 15 (p < 0.01) and to 0.46 +/- 0.14 on day 30 (p < 0.01) in the azithromycin group, and the GH score decreased from 1.9 +/- 0.27 to 0.90 +/- 0.27 on day 15 (p < 0.05) and to 0.70 +/- 0.21 on day 30 (p < 0.01).

CONCLUSION

Azithromycin associated to efficient OHP induced a striking reduction in cyclosporine-induced GH, while efficient OHP alone improved oral symptoms but did not decrease cyclosporine-induced GH.

Efficacy of AZM therapy in patients with gingival overgrowth induced by Cyclosporine A: a systematic review

BACKGROUND

In daily clinical practice of a dental department it's common to find gingival overgrowth (GO) in periodontal patients under treatment with Cyclosporine A (CsA). The pathogenesis of GO and the mechanism of action of Azithromycin (AZM) are unclear. A systematic review was conducted in order to evaluate the efficacy of Azithromycin in patients with gingival overgrowth induced by assumption of Cyclosporine A.

METHODS

A bibliographic search was performed using the online databases MEDLINE, EMBASE and Cochrane Central of Register Controlled Trials (CENTRAL) in the time period between 1966 and September 2008.

RESULTS

The literature search retrieved 24 articles; only 5 were Randomised Controlled Trials (RCTs), published in English, fulfilled the inclusion criteria. A great heterogeneity between proposed treatments and outcomes was found, and this did not allow to conduct a quantitative meta-analysis. The systematic review revealed that a 5-day course of Azithromycin with Scaling and Root Planing reduces the degree of gingival overgrowth, while a 7-day course of metronidazole is only effective on concomitant bacterial over-infection.

CONCLUSION

Few RCTs on the efficacy of systemic antibiotic therapy in case of GO were found in the literature review. A systemic antibiotic therapy without plaque and calculus removal is not able to reduce gingival overgrowth. The great heterogeneity of diagnostic data and outcomes is due to the lack of precise diagnostic methods and protocols about GO. Future studies need to improve both diagnostic methods and tools and adequate classification aimed to determine a correct prognosis and an appropriate therapy for gingival overgrowth.

Inhibition of cyclosporin A-induced gingival overgrowth by azithromycin through phagocytosis: an in vivo and in vitro study

BACKGROUND

The objective of the present study was to investigate the effect of cyclosporin A (CsA) and azithromycin (AZI) on collagen metabolism in the gingiva of rats.

METHODS

Fifty 6-week-old male Sprague-Dawley (SD) rats (weight 120 to 150 g) were randomly distributed into five groups. All groups received various drugs via gastric feeding for 7 weeks. The first group (Mo group) received mineral oil for 7 weeks as a control; the CsA group received CsA in mineral oil for 7 weeks (dosage 30 mg/kg); the CsA/Mo group received CsA in mineral oil for 6 weeks and mineral oil only for the seventh week; the CsA/AZI group received CsA in mineral oil for 6 weeks and AZI (dosage 10 mg/kg) in mineral oil simultaneously with CsA in the seventh week; and the Mo/AZI group received mineral oil for 6 weeks and AZI in mineral oil for the seventh week. All animals were sacrificed for clinical and histological analyses. Gingival fibroblasts were cultured at the fourth passage, and the amount of collagen was measured. Type I collagen and collagenase mRNA were measured by reverse transcription-polymerase chain reaction. Collagen phagocytosis assay also was performed.

RESULTS

Clinically, CsA induced gingival overgrowth in rats, whereas AZI reduced gingival overgrowth. Histological results of the CsA group showed a marked increase of tissue volume compared to the other groups. High collagen amounts were found when gingival overgrowth was induced. However, type I collagen mRNA and collagenase mRNA expressions did not statistically differ among groups. Phagocytosis assay showed that CsA decreased phagocytic activity of gingival fibroblasts, whereas AZI increased the activity. These results suggest that the induction and reduction of CsA-induced gingival overgrowth were closely associated with phagocytic activity.

CONCLUSION

Cyclosporin A decreases collagen degradation by lowering phagocytic activity of rat gingival fibroblasts. Azithromycin partially compensates for this lowered phagocytic activity.

Possible interaction between intravenous azithromycin and oral cyclosporine

A 42-year-old man who had received a cadaveric kidney transplant 9 years earlier was admitted to the hospital with pneumonia. His oral cyclosporine dosage for the past 2 years was stabilized at 100 mg twice/day; his cyclosporine whole blood trough levels 15 days earlier and on the day he was admitted were both 178 ng/ml. The patient was treated with intravenous ceftriaxone and intravenous azithromycin and continued to receive the same dosage of oral cyclosporine. On hospital day 3, his cyclosporine trough level rose to 400 ng/ml and his dosage was reduced by 50%. Trough levels were 181 ng/ml and 175 ng/ml on hospital days 6 and 9, respectively On hospital day 9, the patient stopped receiving azithromycin. On hospital day 14, his cyclosporine trough level dropped to 76 ng/ml, and his cyclosporine dosage was increased back to 100 mg twice/day. The dosage produced trough levels consistent with those before he had been admitted. The patient was discharged on day 20, and a follow-up cyclosporine trough level determined 3 weeks later was 175 ng/ml. Administration of azithromycin may have caused the increased cyclosporine concentrations in this patient through p-glycoprotein inhibition and/or competition for biliary excretion. Azithromycin's interference may be inferred by the increase in cyclosporine levels after administration of this drug and the decrease in cyclosporine levels after its discontinuation-both consistent with the pharmacokinetic properties of cyclosporine. Ceftriaxone and acute-phase reactant activation during infection, however, also may have interfered with the patient's cyclosporine elimination. Azithromycin generally is considered unlikely to interact with cyclosporine. Nonetheless, practitioners should be aware of this possibility and should monitor cyclosporine levels closely, especially in critically ill patients who have other complications.