-
The Netherlands Journal of Medicine Oct 1987
Topics: Adult; Dextrothyroxine; Female; Humans; Hyperlipoproteinemia Type II; Hyperthyroidism
PubMed: 3683682
DOI: No ID Found -
Journal of Endocrinological... Feb 1987Serum levels of thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3) and TSH were measured in euthyroid subjects after a single dose of 4 mg D-thyroxine...
Serum levels of thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3) and TSH were measured in euthyroid subjects after a single dose of 4 mg D-thyroxine (DT4) or of 0.25 mg L-thyroxine (LT4). The same parameters and TSH response to TRH were also evaluated in 7 dyslipidemic patients before and after one month of treatment with 6 mg DT4. T4 levels increased about 165% at h 4 after DT4 and only 47% after LT4; T3 levels remained unchanged until h 10 both after DT4 and after LT4; rT3 levels increased almost 179% after DT4 and only 32% after LT4. TSH levels decreased about 30% after both DT4 and LT4. In the long term study similar variations of the same parameters were observed: basal TSH levels decreased and TSH response to TRH was inhibited in all patients but one; T4 levels increased 62%, T3 levels increased 35%, while rT3 levels increased 545%. Our results show that: both acute and long-term treatment with DT4 suppress TSH secretion; DT4 both in acute and in long-term administration, is preferentially dealogenated in the alaninic ring with production of rDT3, instead of in the phenolic ring with production of DT3. This may contribute to explain its lower metabolic activity.
Topics: Adult; Dextrothyroxine; Humans; Middle Aged; Pituitary Gland; Thyroid Gland; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse
PubMed: 3598077
DOI: 10.1007/BF03347158 -
Medical Toxicology 1987Cholestyramine, colestipol, clofibrate, gemfibrozil, nicotinic acid (niacin), probucol, neomycin, and dextrothyroxine are the most commonly used drugs in the treatment... (Clinical Trial)
Clinical Trial Comparative Study Review
Cholestyramine, colestipol, clofibrate, gemfibrozil, nicotinic acid (niacin), probucol, neomycin, and dextrothyroxine are the most commonly used drugs in the treatment of hyperlipoproteinaemic disorders. While adverse reaction data are available for all of them, definitive data regarding the frequency and severity of potential adverse effects from well-controlled trials using large numbers of patients (greater than 1000) are available only for cholestyramine, clofibrate, nicotinic acid and dextrothyroxine. In adult patients treated with cholestyramine, gastrointestinal complaints, especially constipation, abdominal pain and unpalatability are most frequently observed. Continued administration along with dietary manipulation (e.g. addition of dietary fibre) and/or stool softeners results in diminished complaints during long term therapy. Large doses of cholestyramine (greater than 32 g/day) may be associated with malabsorption of fat-soluble vitamins. Most significantly, osteomalacia and, on rare occasions, haemorrhagic diathesis are reported with cholestyramine impairment of vitamin D and vitamin K absorption, respectively. Paediatric patients have been reported to experience hyperchloraemic metabolic acidosis or gastrointestinal obstruction. Concurrent administration of acidic drugs may result in their reduced bioavailability. Serious adverse reactions to clofibrate will probably limit its role in the future. Of particular concern are ventricular arrhythmias, induction of cholelithiasis and cholecystitis, and the potential for promoting gastrointestinal malignancy which far outweigh the reported benefits in preventing new or recurrent myocardial infarction, cardiovascular death and overall death. Patients with renal disease are particularly prone to myositis, secondary to alterations in protein binding and impaired renal excretion of clofibrate. Drug interactions with coumarin anticoagulants and sulphonylurea compounds may produce bleeding episodes and hypoglycaemia, respectively. Nicotinic acid produces frequent adverse effects, but they are usually not serious, tend to decrease with time, and can be managed easily. Dermal and gastrointestinal reactions are most common. Truncal and facial flushing are reported in 90 to 100% of treated patients in large clinical trials. Significant elevations of liver enzymes, serum glucose, and serum uric acid are occasionally seen with nicotinic acid therapy. Liver enzyme elevations are more common in patients given large dosage increases over short periods of time, and in patients treated with sustained release formulations.(ABSTRACT TRUNCATED AT 400 WORDS)
Topics: Adult; Child; Clinical Trials as Topic; Drug Interactions; Humans; Hypolipidemic Agents
PubMed: 3547004
DOI: 10.1007/BF03259858 -
Journal of the American College of... Dec 1986The Coronary Drug Project was conducted between 1966 and 1975 to assess the long-term efficacy and safety of five lipid-influencing drugs in 8,341 men aged 30 to 64... (Clinical Trial)
Clinical Trial
The Coronary Drug Project was conducted between 1966 and 1975 to assess the long-term efficacy and safety of five lipid-influencing drugs in 8,341 men aged 30 to 64 years with electrocardiogram-documented previous myocardial infarction. The two estrogen regimens and dextrothyroxine were discontinued early because of adverse effects. No evidence of efficacy was found for the clofibrate treatment. Niacin treatment showed modest benefit in decreasing definite nonfatal recurrent myocardial infarction but did not decrease total mortality. With a mean follow-up of 15 years, nearly 9 years after termination of the trial, mortality from all causes in each of the drug groups, except for niacin, was similar to that in the placebo group. Mortality in the niacin group was 11% lower than in the placebo group (52.0 versus 58.2%; p = 0.0004). This late benefit of niacin, occurring after discontinuation of the drug, may be a result of a translation into a mortality benefit over subsequent years of the early favorable effect of niacin in decreasing nonfatal reinfarction or a result of the cholesterol-lowering effect of niacin, or both.
Topics: Adult; Aspirin; Clofibrate; Dextrothyroxine; Estrogens; Follow-Up Studies; Humans; Male; Middle Aged; Myocardial Infarction; Niacin; Time Factors
PubMed: 3782631
DOI: 10.1016/s0735-1097(86)80293-5 -
Rational Drug Therapy Oct 1986
Topics: Cholestyramine Resin; Clofibrate; Colestipol; Dextrothyroxine; Female; Fish Oils; Gemfibrozil; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipoproteinemias; Hypolipidemic Agents; Male; Neomycin; Niacin; Pentanoic Acids; Probucol
PubMed: 3472266
DOI: No ID Found -
Disease-a-month : DM May 1986
Review
Topics: Adolescent; Adult; Child; Child, Preschool; Cholesterol; Cholestyramine Resin; Chylomicrons; Clofibrate; Colestipol; Coronary Disease; Dextrothyroxine; Dietary Fats; Gemfibrozil; Humans; Hyperlipidemia, Familial Combined; Hyperlipidemias; Hyperlipoproteinemia Type I; Hyperlipoproteinemia Type II; Hyperlipoproteinemia Type III; Hyperlipoproteinemia Type IV; Hyperlipoproteinemia Type V; Lipoproteins; Lipoproteins, LDL; Neomycin; Niacin; Pentanoic Acids; Probucol; Receptors, LDL; Triglycerides
PubMed: 3519132
DOI: 10.1016/s0011-5029(86)80011-6 -
Clinical Pharmacy Feb 1986The biochemistry, etiology, and evaluation of hyperlipidemia and its management, including dietary and drug therapies, are discussed. Strong evidence supports the role... (Review)
Review
The biochemistry, etiology, and evaluation of hyperlipidemia and its management, including dietary and drug therapies, are discussed. Strong evidence supports the role of increased cholesterol concentrations as an independent risk factor for coronary artery disease (CAD); however, evidence that elevated triglyceride concentrations are also an independent risk factor remains questionable. The cornerstone of the laboratory diagnosis of hyperlipidemia involves repeated measurement of serum or plasma cholesterol and triglyceride concentrations. The goals of therapy should be to reduce cholesterol or triglyceride concentrations or both to below the 75th percentile, modify co-existing risk factors, individualize the treatment, and minimize any adverse effects. Specific interventions must be determined on the basis of patient age, gender, etiology of hyperlipidemia, presence of other risk factors, and degree of lipid abnormality. The majority of patients may be managed with dietary therapy alone. The three-phase diet developed by the American Heart Association emphasizes a gradual reduction in cholesterol and fats with the substitution of polyunsaturated for saturated fats. Patients at risk for CAD with sustained elevations in plasma cholesterol concentrations above the 95th percentile or a triglyceride concentration above 500 mg/dL after an adequate dietary trial should be considered for drug therapy. The effects of cholestyramine and colestipol hydrochloride, niacin, dextrothyroxine, clofibrate, neomycin sulfate, probucol, gemfibrozil, and mevinolin and compactin on lipids and lipoproteins are reviewed. Hyperlipidemia should be managed systematically using information about the association between increased lipid concentrations and CAD, patient risk factors, and limitations of both diet and drug therapy.
Topics: Clofibrate; Dextrothyroxine; Gemfibrozil; Humans; Hyperlipidemias; Hypolipidemic Agents; Lipids; Lipoproteins; Lovastatin; Naphthalenes; Neomycin; Niacin; Pentanoic Acids; Phenotype; Probucol
PubMed: 3514084
DOI: No ID Found -
The Medical Letter on Drugs and... Aug 1985
Topics: Anticholesteremic Agents; Cholestyramine Resin; Clofibrate; Colestipol; Dextrothyroxine; Gemfibrozil; Humans; Hypolipidemic Agents; Lipoproteins; Neomycin; Niacin; Pentanoic Acids; Probucol; Triglycerides
PubMed: 3860714
DOI: No ID Found -
Journal of the American Academy of... Jul 1985The ability to recognize diverse clinical forms of xanthomas, such as tuberous, planar, eruptive and tendinous, is important in the detection of underlying systemic...
The ability to recognize diverse clinical forms of xanthomas, such as tuberous, planar, eruptive and tendinous, is important in the detection of underlying systemic disease. A variety of primary genetic disorders, as well as numerous secondary conditions such as diabetes, obstructive liver disease, thyroid disease, renal disease, and pancreatitis, can lead to hyperlipoproteinemia that results in the formation not only of xanthomas but also of life-threatening vascular atherosclerosis. An understanding of the pathogenesis of the underlying lipoprotein alterations provides a rational approach to therapy utilizing dietary manipulations and drugs. Such treatment is capable of correcting most disorders of lipid metabolism, and, if appropriate therapy is initiated at the first sign of xanthoma evolution, it may prevent progression of atherosclerosis, provide resolution of xanthomas, and in some instances prevent serious pancreatitis.
Topics: Apoproteins; Arteriosclerosis; Cholestasis; Cholestyramine Resin; Clofibrate; Colestipol; Dextrothyroxine; Diabetes Complications; Female; Humans; Hyperlipidemias; Hyperlipoproteinemia Type III; Hyperlipoproteinemia Type IV; Hyperlipoproteinemias; Hypolipidemic Agents; Hypothyroidism; Kidney Diseases; Lipoproteins; Male; Neomycin; Niacin; Obesity; Pancreatitis; Xanthomatosis
PubMed: 4031142
DOI: 10.1016/s0190-9622(85)70139-9 -
Stereospecific determination and in vivo monodeiodination of thyroxine enantiomers in euthyroid man.Metabolism: Clinical and Experimental Mar 1985To compare in man the absorption, serum disappearance, and peripheral monodeiodination of the thyroxine enantiomers, we studied six euthyroid subjects who, on separate...
To compare in man the absorption, serum disappearance, and peripheral monodeiodination of the thyroxine enantiomers, we studied six euthyroid subjects who, on separate occasions, orally ingested 3 mg of either dextrothyroxine (DT4) or levothyroxine (LT4). We measured the serum concentrations of total T4 (TT4), total T3, and reverse T3 (rT3) by nonstereospecific radioimmunoassay and we determined serum DT4 and LT4 by stereospecific chromatography. Mean serum TT4 levels from 4 hours were significantly greater after LT4 administration. After DT4 administration, stereospecific analysis of serum revealed two T4 peaks that persisted from 2 to 48 hours. The mean serum LT4 level did not significantly change during the 48 hours after DT4 administration. Increases in serum T3 and rT3 were seen from 2 hours after administration of either enantiomer. From 12 hours the levels of both triiodothyronines after LT4 were significantly higher than after DT4. In this short term study we found no evidence that in man DT4 is converted to LT4, nor is it preferentially deiodinated to rT3. The greater and more persistent increases in serum T4 and T3 observed after LT4 probably contribute to the known higher bioactivity of that enantiomer.
Topics: Absorption; Administration, Oral; Adult; Dextrothyroxine; Humans; Radioimmunoassay; Stereoisomerism; Thyroid Diseases; Thyroxine; Time Factors; Triiodothyronine
PubMed: 3974453
DOI: 10.1016/0026-0495(85)90011-3