Clarithromycin Health Dictionary

Also known as Hansen’s disease, this is a chronic bacterial infection caused by Mycobacterium leprae affecting the skin, mucous membranes, and nerves. Infection is now almost con?ned to tropical and subtropical countries – mostly in Africa and India. There are two distinct (polarised) clinical forms: tuberculoid and lepromatous. The former usually takes a benign course and frequently burns out, whereas the latter is relentlessly progressive; between these two polar forms lies an intermediate/dimorphous group. Susceptibility may be increased by malnutrition. Nasal secretions (especially in lepromatous disease) are teeming with M. leprae and constitute the main source of infection; however, living in close proximity to an infected individual seems necessary for someone to contract the disease. M. leprae can also be transmitted in breast milk from an infected mother.

Only a small minority of those exposed to M. leprae develop the disease. The incubation period is 3–5 years or longer. The major clinical manifestations involve skin and nerves: the former range from depigmented, often anaesthetic areas, to massive nodules; nerve involvement ranges from localised nerve swelling(s) to extensive areas of anaesthesia. Advanced nerve destruction gives rise to severe deformities: foot-drop, wrist-drop, claw-foot, extensive ulceration of the extremities with loss of ?ngers and toes, and bone changes. Eye involvement can produce blindness. Laryngeal lesions produce hoarseness and more serious sequelae. The diagnosis is essentially a clinical one; however, skin-smears, histological features and the lepromin skin-test help to con?rm the diagnosis and enable the form of disease to be graded.

Although the World Health Organisation had originally hoped to eliminate leprosy worldwide by 2000, that has proved an unrealistic target. The reason is an absence of basic information. Doctors are unable to diagnose the disorder before a patient starts to show symptoms; meanwhile he or she may have already passed on the infection. Doctors do not know exactly how transmission occurs or how it infects humans – nor do they know at what point a carrier of the bacterium may infect others. The incidence of new infections is still more than 650,000 cases a year or about 4.5 cases per 10,000 people in those countries worst affected by the disease.

Treatment Introduction of the sulphone compound, dapsone, revolutionised management of the disease. More recently, rifampicin and clofazimine have been added as ?rst-line drugs for treatment. Second-line drugs include minocycline, o?oxacin and clarithromycin; a number of regimens incorporating several of these compounds (multi-drug regimens – introduced in 1982) are now widely used. A three-drug regime is recommended for multi-bacillary leprosy and a two-drug one for parcibacillary leprosy. Dapsone resistance is a major problem worldwide, but occurs less commonly when multi-drug regimens are used. Older compounds – ethionamide and prothionamide

– are no longer used because they are severely toxic to the liver. Corticosteroids are sometimes required in patients with ‘reversal reaction’. Supportive therapy includes physiotherapy; both plastic and orthopaedic surgery may be necessary in advanced stages of the disease. Improvement in socio-economic conditions, and widespread use of BCG vaccination are of value as preventive strategies. Early diagnosis and prompt institution of chemotherapy should prevent long-term complications.... leprosy

A group of ANTIBIOTICS. The original macrolide, ERYTHROMYCIN, was discovered in the early 1950s and used successfully as an alternative to PENICILLIN. The name ‘macrolide’ derives from the molecular structure of this group, three others of which are clarithromycin, azithromycin and spiramycin. Macrolides check PROTEIN synthesis in BACTERIA and the latest ones are, like erythromycin, active against several bacterial species including gram-positive COCCI and rods. In addition, they act against Haemophilus in?uenzae. Clarithromycin is potent against Helicobacter pylori; azithromycin is e?ective against infections caused by Legionella spp. (see LEGIONNAIRE’S DISEASE) and GONOCOCCI. Spiramycin is a restricted-use macrolide prescribed for pregnant patients with TOXOPLASMOSIS.... macrolides