Drug therapy used in treatment of Wernick's encephalopathy:
Thiamine ( vit B, )- It is present in the outer layers of cereals (rice polishing), pulses, nuts, green Vegetables, yeasts, egg and meat. Absorption and fate- Physiological amounts are absorbed by active transpo. When large doses are given orally, passive diffusion also occurs. Limited amounts are Stored in tissues. About 1 mg/day is degraded in the Body excess is rapidly excreted in the urine. Physiological role After conversion in the body to Thiamine pyrophosphate, it acts as a coenzyme in carbohydrate metabolism: decarboxylation of ketoacids and hexose monophosphate shunt. The requirement is dependent upon carbohydrate intake-about 0.3 mg/ 1000 Kcal. It also plays some role in neuromuscular transmission. Deficiency symptoms -The syndrome of thiamine deficiency beriberi is seen in dry and wet forms: Dry beriberi: Neurological symptoms are prominent-polyneuritis with numbness, tingling, hyperesthesia, muscular weakness and atrophy resulting in 'wrist drop', 'foot drop', paralysis of the whole limb, mental changes, sluggishness, poor memory, loss of appetite and constipation. Wet beriberi: Cardiovascular system is primarily affected-palpitation, breathlessness, high out- put cardiac failure and ECG changes. Therapeutic uses 1. Prophylactically (2-10 mg daily) in infants, pregnant women, chronic diarrheas, patients on parenteral alimentation. Glucose infusion unmasks marginal thiamine deficiency. 2. Beriberi-100 mg/day i.m. or i.v. till symptoms regress-then maintenance doses orally. 3. Acute alcoholic intoxication: thiamine 100 mg is added to each vac of glucose solution infused. Most neurological symptoms in chronic alcoholics are due to thiamine deficiency-peripheral neuritis, Wernick's encephalopathy, Korsakoff's psychosis: give 100 mg/ day parenterally. 4. In neurological and cardiovascular disorders, hyperemesis gravidarum, chronic anorexia, and obstinate constipation-thiamine has been used even without definite proof of its deficiency- symptoms improve dramatically if thiamine deficiency has been causative. Adverse effects Thiamine is nontoxic. Sensitivity reactions sometimes occur ESSENTIALS of medical PHARMACOLOGY SEVENTH EDITION KD TRIPATHI Page:912 913 914
Diazepam
Disulfiram
Thiamine
Cynocobalamine
Other topics and Adverse effects