THIAMINE IS USED IN THE TREATMENT AND PREVENTION OF THIAMINE DEFICIENCY. IT IS GIVEN BY MOUTH, THE PREFERRED ROUTE, OR IF NECESSARY BY THE INTRAMUSCULAR OR INTRAVENOUS ROUTES (BUT SEE HYPERSENSITIVITY); INTRAVENOUS INJECTIONS SHOULD BE GIVEN SLOWLY OVER 10 MINUTES. IN THE TREATMENT OF MILD CHRONIC THIAMINE DEFICIENCY USUAL DOSES OF 10 TO 25 MG DAILY BY MOUTH, IN SINGLE OR DIVIDED DOSES, HAVE BEEN RECOMMENDED. IN SEVERE THIAMINE DEFICIENCY DOSES OF UP TO 300 MG DAILY ARE GIVEN, AND EVEN HIGHER DAILY DOSES MAY BE USED IN WERNICKE-KORSAKOFF SYNDROME BY THE INTRAVENOUS ROUTE.
THIAMINE IS USUALLY GIVEN AS EITHER THE HYDROCHLORIDE OR NITRATE SALTS ALTHOUGH OTHER SALTS SUCH AS THE DICAMSYLATE, DISULFIDE, MONOPHOSPHATE (MONOPHOSPHOTHIAMINE) OR PYROPHOSPHATE (COCARBOXYLASE) MAY BE USED.
OTHER COMPOUNDS THAT POSSESS VITAMIN B1 ACTIVITY AND MAY BE GIVEN AS ALTERNATIVES TO THIAMINE INCLUDE BENFOTIAMINE, CYCOTIAMINE, OCTOTIAMINE, PROSULTIAMINE, AND SULBUTIAMINE. ACETIAMINE, BISBENTIAMINE, AND FURSULTIAMINE HAVE ALSO BEEN USED.
DIABETIC NEUROPATHY.
IN A SMALL PLACEBO-CONTROLLED STUDY, BENFOTIAMINE 100 MG GIVEN FOUR TIMES DAILY BY MOUTH SIGNIFICANTLY IMPROVED NEUROPATHIC PAIN IN PATIENTS WITH DIABETIC POLYNEUROPATHY .
WERNICKE-KORSAKOFF SYNDROME.
THE WERNICKE-KORSAKOFF SYNDROME IS A MANIFESTATION OF THIAMINE DEFICIENCY SEEN PARTICULARLY IN ALCOHOLICS, BUT WHICH MAY ACCOMPANY OTHER CONDITIONS INCLUDING STARVATION OR PROLONGED FASTING, OR PERSISTENT VOMITING. IT WAS ORIGINALLY CLASSIFIED AS TWO SEPARATE DISORDERS, WERNICKE'S ENCEPHALOPATHY AND KORSAKOFF'S SYNDROME, BUT THESE ARE NOW THOUGHT TO REPRESENT ASPECTS OF A SINGLE PATHOLOGICAL PROCESS.
CLASSICAL WERNICKE'S SYMPTOMS COMPRISE CONFUSION, ATAXIA, OPHTHALMOPLEGIA, AND NYSTAGMUS. OPHTHALMOPLEGIA AND ATAXIA MAY PRECEDE THE MENTAL SYMPTOMS BY SOME DAYS. HYPOTHERMIA MAY BE SEEN, AND COLLAPSE AND SUDDEN DEATH MAY OCCUR IN SOME PATIENTS. THE MANIFESTATIONS OF KORSAKOFF'S SYNDROME ARE SHORT-TERM MEMORY LOSS, LEARNING DEFICITS, AND CONFABULATION. THE CONDITIONS ARE ASSOCIATED WITH DEMYELINATION AND GLIAL PROLIFERATION, AS WELL AS HAEMORRHAGIC LESIONS, MAINLY IN THE PERIVENTRICULAR REGIONS OF THE BRAIN; CHARACTERISTIC BIOCHEMICAL ABNORMALITIES INCLUDE RAISED SERUM-PYRUVATE CONCENTRATION, WHICH HAS BEEN POSTULATED AS A CAUSE OF ENCEPHALOPATHY.
EARLY RECOGNITION AND TREATMENT IS IMPORTANT, BOTH BECAUSE OF THE RISK OF COLLAPSE AND SUDDEN DEATH, AND TO PREVENT IRREVERSIBLE DAMAGE TO THE CNS. KORSAKOFF SYMPTOMS RESPOND LESS WELL TO TREATMENT THAN THOSE ASSOCIATED WITH WERNICKE'S ENCEPHALOPATHY, AND MAY INDEED ONLY BECOME EVIDENT ON TREATMENT.
TREATMENT IS WITH PARENTERAL THIAMINE, PREFERABLY INTRAVENOUSLY, TO ENSURE ADEQUATE ABSORPTION; ANY RISKS OF PARENTERAL TREATMENT ARE CONSIDERED JUSTIFIABLE. ALTHOUGH AS LITTLE AS 2 OR 3 MG MAY BE ENOUGH TO REVERSE THE OCULAR SYMPTOMS, WHICH GENERALLY BEGIN TO IMPROVE IN 1 TO 6 HOURS, DOSES OF AT LEAST 100 MG SHOULD BE GIVEN INITIALLY. (IN PRACTICE A TYPICAL DOSE IS 500 MG GIVEN INTRAVENOUSLY WITH OTHER VITAMINS EVERY 8 HOURS, FOR 2 DAYS IF SYMPTOMS PERSIST, AND FOLLOWED BY 100 MG TWICE DAILY BY MOUTH, OR 250 MG DAILY INTRAVENOUSLY UNTIL THE PATIENT CAN TAKE ORAL THIAMINE.) THE ATAXIA AND ACUTE CONFUSIONAL STATE MAY ALSO RESOLVE DRAMATICALLY ALTHOUGH IMPROVEMENT MAY NOT BE NOTED FOR DAYS OR MONTHS. EVEN SEVERAL MONTHS AFTER THE ONSET OF SYMPTOMS, TREATMENT WITH HIGH DOSES OF THIAMINE HAS OCCASIONALLY RESULTED IN RECOVERY. THE EFFECTS OF THE SYNDROME ON MEMORY ARE MUCH HARDER TO REVERSE. SOME 25% OF PATIENTS MAKE A FULL, AND 50% A PARTIAL, RECOVERY. DYSMENORRHOEA - 100 MG DAILY FOR 3-4 MTHS.