Oral presentation of minocycline-induced black bone disease

Tetracyclines and bone: Unclear actions with potentially lasting effects

Tetracyclines are a broad-spectrum class of antibiotics that have unclear actions with potentially lasting effects on bone metabolism. Initially isolated from Streptomyces, tetracycline proved to be an effective treatment for Gram +/- infections. The emergence of resistant bacterial strains commanded the development of later generation agents, including minocycline, doxycycline, tigecycline, sarecycline, omadacycline, and eravacycline. In 1957, it was realized that tetracyclines act as bone fluorochrome labels due to their high affinity for the bone mineral matrix. Over the course of the next decade, researchers discerned that these compounds are retained in the bone matrix at high levels after the termination of antibiotic therapy. Studies during this period provided evidence that tetracyclines could disrupt prenatal and early postnatal skeletal development. Currently, tetracyclines are most commonly prescribed as a long-term systemic therapy for the treatment of acne in healthy adolescents and young adults. Surprisingly, the impact of tetracyclines on physiologic bone modeling/remodeling is largely unknown. This article provides an overview of the pharmacology of tetracycline drugs, summarizes current knowledge about the impact of these agents on skeletal development and homeostasis, and reviews prior work targeting tetracyclines' effects on bone cell physiology. The need for future research to elucidate unclear effects of tetracyclines on the skeleton is addressed, including drug retention/release mechanisms from the bone matrix, signaling mechanisms at bone cells, the impact of newer third generation tetracycline antibiotics, and the role of the gut-bone axis.

Medication-Induced Oral Hyperpigmentation: A Systematic Review

BACKGROUND

Medication-induced oral hyperpigmentation is an oral condition that impacts patients' quality of life and has been linked to many systemic therapeutic agents. The exact pathogenesis of tissue pigmentation varies greatly and is not completely known. This systematic review aimed to present data on the causal association between medications and the development of oral/mucosal pigmentation as an adverse drug reaction.

METHODS

A systematic review and analysis of literature were conducted using the following databases: PubMed, Science Direct, ProQuest, Web of Science, and Scopus. The systematic review included original articles written in English and published between January 1982 and June 2020. Following the PRISMA statement, eligible articles were systematically reviewed, and data were extracted from eligible studies and analyzed.

RESULTS

A total of 235 articles were identified, of which 57 met the inclusion criteria and were included in this review. The mean age of included patients was 46.2±16.38 years (range: 10-90 years) with a male to female ratio of 1:1.45. Oral mucosal hyperpigmentation was reported following the use of several classes of medications such as antiviral (eg, zidovudine), antibiotic (eg, minocycline), antimalarial (eg, chloroquine), anti-fungal (eg, ketoconazole), antileprotic (eg, clofazimine), antihypertensive (eg, amlodipine), chemotherapeutic, and antineoplastic drugs. The risk of developing oral pigmentation was significantly higher with antimalarial medications, antibiotics, antineoplastic and chemotherapeutic agents. Medication-induced oral hyperpigmentation was most frequent among women and in the hard palate.

CONCLUSION

Future research is warranted to better understand the pathogenesis and risk factors for medication-induced oral hyperpigmentation in order to reassure patients during prescription and management.

Rusty green stained temporal bone associated with exposure to tetracycline: an unusual presentation of black bone disease

OBJECTIVE

To review the phenomenon and implications of temporal bone and craniofacial bone staining in the context of prolonged exposure to tetracycline antibiotic.

METHODS

Case report and literature review.

RESULTS

A 52-year-old male with a 5-year history of tetracycline use presented to undergo tympanomastoidectomy and was found to have an unusual rusty green pigmentation of the entire aspect of the exposed temporal bone. A literature review revealed more than 20 cases of tetracycline-induced pigmentation of intraoral maxillary and mandibular bone, and 2 prior cases involving the cranial bones.

CONCLUSION

Tissue and organ pigmentation is an unexpected and unfavourable consequence of the use of tetracyclines, particularly minocycline. Tetracycline is contraindicated in children because of the risk for dysosteogenesis and enamel hypoplasia. In adults, although the unusual staining may present as an unexpected dilemma upon surgical exposure, current research shows no significant clinical consequences for this type of pigmentation.

Minocycline-induced black bone disease encountered during total knee arthroplasty

Finding discolored bone intraoperatively can be confusing and concerning to orthopedic surgeons. Multiple causes of pigmented bone exist, including ochronosis, metabolic bone diseases, metal deposits, sequestrum, metastatic disease, and minocycline use. Bone quality is an important consideration in intraoperative decision making with respect to components and fixation options in total joint arthroplasty. Abnormal bone encountered in routine arthroplasty can raise concerns over the integrity and healing potential of the bone when the etiology is uncertain.Minocycline is a drug routinely used for the treatment of acne, rosacea, and rheumatoid arthritis. Pigmentation is a commonly recognized adverse reaction associated with most of the drugs in the tetracycline family, affecting the skin, nails, teeth, oral mucosa, bones in the oral cavity, ocular structures, cartilage, thyroid, and other visceral structures.This article describes a case of pigmented bone secondary to minocycline use in a 55-year-old woman undergoing total knee arthroplasty. This entity has rarely been documented in the orthopedic literature; however, orthopedic surgeons should be aware of this side effect secondary to the widespread use of minocycline. Questions concerning the effect of minocycline on bone metabolism and structural integrity have yet to be fully answered, but an understanding and recognition of the entity will help guide surgeons with intraoperative decision making.

[Black bone disease of the skull and facial bones]

INTRODUCTION

We report the case of a patient with a craniofacial black bone disease. This was discovered accidentally during a coronal approach.

CASE REPORT

A 38-year-old patient was referred to our unit for facial palsy having appeared 10 years before. Rehabilitation of the facial palsy was performed with a lengthening temporal myoplasty and lengthening of the upper eyelid elevator. An unusual black color of the skull was observed at incision of the coronal approach. Subperiostal dissection of skull and malars confirmed the presence of a black bone disease. A postoperative history revealed minocycline intake (200mg per day) during 3 years.

DISCUSSION

This craniofacial black bone disease was caused by minocycline intake. The originality of this case is to see directly the entire craniofacial skeleton black. This abnormal pigmentation may affect various organs or tissues. Bone pigmentation is irreversible unlike that of the mouth mucosa or of the skin. This abnormal pigmentation is usually discovered accidentally.

Corneal staining after treatment with topical tetracycline

PURPOSE

The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline.

METHODS

A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of bacterial sensitivity testing. After 3 weeks of intensive treatment, the donor cornea was stained with a brownish hue, which was ascribed to the tetracycline drops.

RESULTS

One patient with crystalline keratopathy developed corneal staining after intensive treatment with topical tetracycline eye drops. After a year of follow-up, the staining of the cornea had not changed significantly.

CONCLUSION

Hourly topical tetracycline eye drops may induce corneal pigmentation. To our knowledge, this is the first published case report of corneal staining caused by tetracycline eye drops.

Safety of doxycycline and minocycline: a systematic review

OBJECTIVE

The goal of this review was to summarize the available literature covering the safety profiles of oral doxycycline and minocycline.

METHODS

Scientific literature published between 1966 and August 2003 was searched using the MEDLINE, EMBASE, and Biosis databases (search terms: minocycline or doxycycline, each paired with adverse reaction, adverse event, and side effect, and doxycycline or minocycline with the limits English language, human, and clinical trials). Safety information was collected from case reports and clinical trials. Adverse event (AE) rates in the United States were calculated by comparing data from the MedWatch AE reporting program used by the US Food and Drug Administration (FDA) with the number of new prescriptions dispensed for each drug from January 1998 to August 2003.

RESULTS

Between 1966 and 2003, a total of 130 and 333 AEs were published in case reports of doxycycline and minocycline, respectively. In 24 doxycycline clinical trials (n = 3833) and 11 minocycline trials (n = 788), the ranges in incidence of AEs were 0% to 61% and 11.7% to 83.3%, respectively. Gastrointestinal AEs were most common with doxycycline; central nervous system and gastrointestinal AEs were most common with minocycline. From January 1998 to August 2003, the FDA MedWatch data contained 628 events for doxycycline and 1099 events for minocycline reported in the United States. Approximately 47,630,000 doxycycline and 15,234,000 minocycline new prescriptions were dispensed in the United States during that period, yielding event rates of 13 per million for doxycycline and 72 per million for minocycline, based on FDA data.

CONCLUSIONS

Between 1998 and 2003, doxycycline was prescribed 3 times as often as minocycline. The incidence of AEs with either drug is very low, but doxycycline had fewer reported AEs. Although more head-to-head clinical trials are needed for a direct comparison of AE frequency, these preliminary data from separate reports suggest the possibility that AEs may be less likely with doxycycline than minocycline.

Minocycline-induced cutaneous hyperpigmentation: confocal laser scanning microscope analysis

BACKGROUND

Minocycline has a characteristic yellow-green fluorescent emission. This fluorescence has been previously demonstrated only in type 1 minocycline-induced skin hyperpigmentation.

OBJECTIVE

To investigate whether the fluorescence can be detected in other types of minocycline-induced cutaneous hyperpigmentation, and to study the possible mechanisms.

METHODS

Biopsies of pigmented and nonpigmented skin from 3 patients with different types of skin hyperpigmentation induced by minocycline were analysed by light microscopy and Confocal Laser Scanning Microscope (CLSM).

RESULTS

A yellow-green fluorescence was observed in the hyperpigmented skin of two patients with type 2, and one patient with type 4 minocycline-induced cutaneous hyperpigmentation. No fluorescence was detected in the non-pigmented skin.

CONCLUSION

Minocycline can possibly serve as a fluorescent probe in the diagnosis of all types of minocycline-induced cutaneous hyperpigmentation.

Black pigmentation of bone due to long-term minocycline use

Minocycline-induced dark pigmentation has been described affecting the oral cavity (teeth, mucosa, alveolar bone), skin, nails, eyes and thyroid. To date, there is no report of other bones being affected. We report a case of black pigmentation of the acromian in a patient who had used minocycline on a long-term basis for acne rosecea. Biopsy of the iliac crest revealed that the pelvis was also affected.

Oral mucosal pigmentation secondary to minocycline therapy: report of two cases and a review of the literature

Minocycline is a semisynthetic broad-spectrum antimicrobial agent that was first introduced into clinical practice in 1967. The most common use of minocycline is for the long-term treatment of acne vulgaris. A well-recognized side effect of minocycline treatment is pigmentation, which has been reported in multiple tissues and fluids including thyroid, skin, nail beds, sclera, bone, and teeth. While there have been several reports of oral pigmentation following minocycline therapy, these have been, for the most part, pigmentation of the underlying bone with the overlying oral mucosa only appearing pigmented. We report two cases of actual pigmented oral mucosal lesions on the hard palate secondary to minocycline therapy with the accompanying histopathology, followed by a discussion of minocycline-induced oral pigmentation and a differential diagnosis of these lesions.

Coptidis rhizoma inhibits growth and proteases of oral bacteria

OBJECTIVE

The aim of this study was to investigate the antibacterial effect of Coptidis Rhizoma (CR), a traditional medicinal plant, on oral bacteria.

MATERIALS AND METHODS

CR extract was prepared by boiling CR in water for 2 h. Alkaloids contained in CR extract were assayed by high performance liquid chromatography (HPLC). Antibacterial activity of CR extract was estimated from the lowest concentration that did not permit bacterial growth (minimum inhibitory concentration, MIC) and the concentrations that inhibited 50% of bacterial proteolytic activity (IC50).

RESULTS

CR extract inhibited the growth of Actinomyces naeslundii, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Actinobacillus actinomycetemcomitans at MIC of 0.031-0.25 mg ml(-1), whereas it had less inhibitory effect (MIC: 0.5-2 mg ml(-1)) on the growth of Streptococcus and Lactobacillus. The major active component of CR extract was berberine (Ber), an alkaloid, and its inhibiting specificity to bacterial growth was similar to that of CR extract. CR extract and Ber were bacteriostatic at the MICs against most of the bacteria, and bacteriocidal at the concentrations higher than the MICs. Ber inhibited the activities of collagenase from P. gingivalis and A. actinomycetemcomitans.

CONCLUSION

CR extract and Ber had an inhibitory effect on periodontopathogenic bacteria. These results suggest the possibility of their clinical application for the treatment of periodontal diseases.

Minocycline and oral pigmentation

Minocycline is a semisynthetic tetracycline used in the treatment of inflammatory acne because of its broad spectrum of activity, less common development of resistant organisms, and its anti-inflammatory effects. A number of adverse reactions are reported, including skin and oral pigmentation. This paper details the pharmacology of minocycline and describes the pigmentation and likely mechanisms active in both hard and soft tissues. Oral pigmentation usually involves the hard tissues only and presents typically as a discrete band occupying the central zone of the alveolar mucosa and palate. As with other sites, it may persist following withdrawal of the drug. Early recognition by the dental practitioner may allow an alternative form of therapy to be sought, minimizing the likelihood of a long-term aesthetic problem.

Lesions associated with drug reactions

Several of the more common oral lesions secondary to medication use have been presented in this article. Although some of these conditions are specific to the oral tissues, some are not. Numerous cutaneous reactions to medications have mucosal counterparts. It is important for the clinician to recognize that many oral lesions are simply a manifestation of a systemic condition and should be managed with that in mind.