Management of diabetic neuropathy - abstract

ABSTRACT

Over 50 percent of diabetics have measuable neuropathy, but only about 15 percent have symptoms (Dyck et al, 1993), of which pain is the most distressing. The pain of diabetic neuropathy (DN) is thought to arise from regenerating axons and spontaneously firing small nociceptive fibres. In addition, poor diabetic control (hyperglycaemia) may reduce the individual pain threshold. Ordinary analgesics are usually ineffective and opiates should be used cautiously because both in the depressed and non-depressed but side effects are common, especially in the elderly patient. The starting dose should be 10 - 25 mg given at night to controlnocturnal exacerbations of pain. Imipramine, another tricyclic anti-depressant with less anticholinergic inhibitor, are alternatives to amitriptyline. Pain which is lancinating in quality may repond better to carbamazepine at a starting dose of 200 mg daily. Mexilitene has also been shown to be effective in painful DN. Topical capsaicin which depletes nociceptive C fibres of their neurotransmitter, substance P, may be used as an adjunct to oral therapy. The patient with painless symmetrical polyneuropathy is at risk for the development of foot ulceration at areas of abnormally high pressure which arise as a result of destruction of the small joints of the foot. Patienst education regarding daily obsessive foot care is essential. Specific strategies for the management of plantar foot ulceration include non-weight bearing, redistribution of foot pressure by the use of various plaster-of Paris walking devices, treatment of infection with appropriate antibiotics, and the use of hyperbaric oxygen where available. Some complications of autonomic neuropathy which may respond to pharmacotherapy include gastroparesis (metoclopamide, erthromycin, domperidone), nocturnal diarrhoea (tetracycline), gustatory sweating (preprandial propantheline) and postural hypotension (fludrocortisone). The results of the recently reported multicentre trial (DCCI) clearly show that risk of developing neuropathy can be significantly reduced by intensive glycaemic control. Physicians need to be aware of the various syndromes of DN in order to advise and treat complications if and when they arise (AU)