Drug-induced palatal pigmentation

In Vivo Activity of Repurposed Amodiaquine as a Host-Targeting Therapy for the Treatment of Anthrax

Anthrax is caused by Bacillus anthracis and can result in nearly 100% mortality due in part to anthrax toxin. Antimalarial amodiaquine (AQ) acts as a host-oriented inhibitor of anthrax toxin endocytosis. Here, we determined the pharmacokinetics and safety of AQ in mice, rabbits, and humans as well as the efficacy in the fly, mouse, and rabbit models of anthrax infection. In the therapeutic-intervention studies, AQ nearly doubled the survival of mice infected subcutaneously with a B. anthracis dose lethal to 60% of the animals (LD₆₀). In rabbits challenged with 200 LD₅₀ of aerosolized B. anthracis, AQ as a monotherapy delayed death, doubled the survival rate of infected animals that received a suboptimal amount of antibacterial levofloxacin, and reduced bacteremia and toxemia in tissues. Surprisingly, the anthrax efficacy of AQ relies on an additional host macrophage-directed antibacterial mechanism, which was validated in the toxin-independent Drosophila model of Bacillus infection. Lastly, a systematic literature review of the safety and pharmacokinetics of AQ in humans from over 2 000 published articles revealed that AQ is likely safe when taken as prescribed, and its pharmacokinetics predicts anthrax efficacy in humans. Our results support the future examination of AQ as adjunctive therapy for the prophylactic anthrax treatment.

Oral-maxillofacial adverse events related to antimalarials

Malaria is a worldwide parasitic disease, which affects millions of lives every year. Various medications are recommended by WHO for prevention and treatment of malaria. However, adverse events caused by antimalarials were frequently reported, some of which were severe and fatal. Disorders of many organs related to antimalarials have been well recognized, whereas few studies concentrated on the relationship between antimalarials and oral-maxillofacial system health. Current review generalized the relevance of antimalarials to the health of oral-maxillofacial part and raised an urgent need to form a standard management for antimalarial-related oral-maxillofacial adverse events.

Adverse Drug Reactions in the Orofacial Region

A wide spectrum of drugs can sometimes give rise to numerous adverse orofacial manifestations, particularly dry mouth, taste disturbances, oral mucosal ulceration, and/or gingival swelling. There are few relevant randomized double-blind controlled studies in this field, and therefore this paper reviews the data from case reports, small series, and non-peer-reviewed reports of adverse drug reactions affecting the orofacial region (available from a MEDLINE search to April, 2003). The more common and significant adverse orofacial consequences of drug therapy are discussed.

Diagnosis of oral pigmentations and malignant transformations

BACKGROUND

Oral pigmentation is a common finding in the mouth. Pigmentation can be either normal or abnormal discoloration of oral mucous membrane. The purpose of this review mainly focuses on the main oral pigmented lesions, in order to help the clinicians establish a better approach towards the patients with pigmented oral lesions and to provide thorough knowledge regarding such lesions for patient reassurance, early definitive diagnosis and prompt treatment.

METHODS

Relevant data concerning oral pigmented lesions, clinical features and the possibility of malignant transformation of such lesions were reviewed thoroughly from pubmed literature published in English. Pigmented lesions affecting the skin were not included in our review.

RESULTS

Few pigmented lesions have been identified and their tendency to become malignant has been reported in the literature. The oral lesions showing malignant transformation reported were mostly case series. Unfortunately, due to lack of long-term studies, follow ups and randomized controlled studies in this respect it was difficult to draw a statistical analysis. This information is quite crucial for general dental practitioners to improve their understanding regarding oral lesions and to differentiate between normal and diseased conditions, so that they can master the skill of differential diagnosis, definitive diagnosis and prompt treatment.

CONCLUSION

Oral pigmentation may present as focal, multifocal or diffused macular or tumefactive lesions. They may greatly vary in color as blue, purple, brown, gray or black depending on the quantity and site of melanin in the tissues [1]. Etiology of pigmentation can be multi factorial. Mostly pigmentation is physiologic but at times it can be a precursor of severe diseases. Lesions may be caused by localized harmless accumulations of melanin, hemosiderin or exogenous metals or they may be a sign of underlying systemic or genetic disease. A few lesions may be associated with life-threatening medical conditions that require immediate intervention. The differential diagnosis for any pigmented lesion is extensive, as it includes examples of endogenous and exogenous pigmentations. Although biopsy is a helpful and necessary aid in the diagnosis of focally pigmented lesions, with diffuse pigmentation lesions require a thorough dental and medical history and laboratory investigations.

Pigmentary changes in rat oral mucosa following antimalarial therapy

Pharmacogenic pigmentation of the oral mucosa has been reported following the use of a number of anti-malarial drugs. The nature and distribution of the pigment is inconclusive in the literature. The aim of the present study was to document pigment deposition within the oral mucosa of DA rats following prolonged chloroquine and pyrimethamine administration. The drugs were given as a combined dosage and separately to different groups via stomach gavage tube. After 12 weekly administrations the palatal mucosa was examined histochemically and ultrastructurally for changes in numbers and size of active melanocytes using the dopa-oxidase technique. The serum was analysed for changes in ACTH and testosterone levels. Morphometric analysis of cells incubated for dopa-oxidase showed a significant increase in the size of dopa positive cells with both drugs but an increase in the number of active melanocytes with chloroquine only. Serum levels of ACTH remained unchanged with both drugs but pyrimethamine caused an elevation in testosterone.