Biomedical subjects

A Cheng-Lai

Publications and source records attributed to A Cheng-Lai.

5 recordsLinked to original sources

PubMedDate not supplied

Cardiovascular drug highlight: hirudin.

Hirudin is a polypeptide of 65 to 66 amino acids derived from the saliva of the medicinal leech Hirudo medicinalis. It is the most potent naturally occurring specific inhibitor of thrombin. Through genetic engineering, recombinant forms of hirudin (r-hirudin) have been made available in sufficient quantities for therapeutic use. Because hirudin is capable of inhibiting clot-bound thrombin and fluid-phase thrombin, it has great potential for management of patients with various types of thromboembolic complications. Clinical trials with hirudin have been conducted in patients with coronary artery disease, heparin-induced thrombocytopenia, and in patients undergoing orthopedic surgery. The results of selected clinical trials in each of these areas are reviewed here. At present, most clinical benefits of r-hirudin have been demonstrated in the management of patients with heparin-induced thrombocytopenia. For this reason, lepirudin (a form of r-hirudin) has recently been approved by the United States Food and Drug Administration (FDA) for anticoagulation in patients with heparin-induced thrombocytopenia and associated thromboembolic disease.

Anticoagulants↗

PubMedDate not supplied

Cerivastatin.

Cerivastatin is a synthetic and enantiomerically pure 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. It has been recognized for its high pharmacologic potency, uncomplicated pharmacokinetic profile, and low drug-interaction potential. The efficacy of cerivastatin has been demonstrated in a number of clinical trials involving patients with primary hypercholesterolemia and mixed dyslipidemia. Cerivastatin was found to have dose-dependent reduction in total cholesterol and low-density lipoprotein (LDL) cholesterol. At the 0.4 mg daily dose, cerivastatin was found to lower LDL cholesterol by approximately 35% (mean reductions of 33-39%). The triglyceride-lowering effect of cerivastatin is also dose dependent; however, there is a much stronger association between baseline triglyceride levels and the triglyceride-lowering effect of cerivastatin. A dosage of 0.4 mg daily has been shown to reduce triglycerides by a mean of 28% in patients with baseline triglyceride levels of > 300 mg/dL. At the time of its initial approval by the US Food and Drug Administration (FDA) in 1997, cerivastatin was available only in 0.2 mg and 0.3 mg strengths. The recent FDA approval of the 0.4-mg strength dose has made cerivastatin a more competitive drug in lipid-lowering efficacy among the HMG-CoA reductase inhibitors.

Clinical Trials as Topic↗

PubMedDate not supplied

Cardiovascular drug therapy in the elderly.

Cardiovascular diseases of various etiologies are most prevalent in the elderly, and there are many pharmacologic issues that need to be considered when prescribing drug therapies to this population. Aging itself alters the absorption, distribution, metabolism, and excretion of many drugs. Certain drugs, such as digoxin, lidocaine, and warfarin, need to be used with great caution in older patients because of a greater potential for drug toxicity. Elderly patients often are prescribed multiple drugs for different conditions, making them susceptible to major drug-drug interactions. Recommendations are provided to help ensure safe prescribing practices of cardiac drugs in older patients.

Age Factors↗

PubMedDate not supplied

Orlistat.

Obesity is a risk factor for cardiovascular disease. Orlistat is a gastric and pancreatic lipase inhibitor indicated for the management of obesity. It is the first antiobesity agent that is not a centrally acting appetite suppressant; instead, it decreases absorption of dietary fat in the gastrointestinal tract. The effects of orlistat on weight loss, weight regain, and on a number of obesity-related risk factors have been assessed in large clinical trials of 1 to 2 years' duration. Compared with subjects who received placebo and a hypocaloric diet alone, weight loss of at least 5 to 10% of initial body weight was observed in a significantly larger number of subjects who were treated with orlistat plus a hypocaloric diet during the first year of treatment. Subjects who received orlistat 120 mg three times daily regained significantly less weight than subjects who received placebo during the second year of treatment. In addition, orlistat was found to have favorable effects on blood pressure and concentrations of serum lipid, glucose, and insulin. Gastrointestinal events are the most common adverse effects experienced by patients who received orlistat; however, most of these events were mild to moderate in intensity, transient in duration, and decreased considerably during the second year of treatment.

Anti-Obesity Agents↗

PubMedDate not supplied

Rosiglitazone: an agent from the thiazolidinedione class for the treatment of type 2 diabetes.

Great advances have been made in the management of diabetes during the past decade. Whereas only one class of oral medications (the sulfonylureas) was available for the treatment of type 2 diabetes in the early 1990s, we now have five classes of oral antidiabetic agents from which to choose. The thiazolidinedione class of medications was first introduced to the United States when troglitazone was marketed during early 1997. Rosiglitazone, approved by the FDA during the spring of 1999, was the second thiazolidinedione to be marketed in the United States. Similar to troglitazone, rosiglitazone improves insulin sensitivity in patients with type 2 diabetes by activating peroxisome proliferator-activated receptor-gamma (PPARgamma) receptors in adipose tissues, skeletal muscles, and the liver. The efficacy and safety of rosiglitazone therapy in patients with type 2 diabetes have been demonstrated in a number of clinical studies, which are summarized in this article. Selected characteristics of rosiglitazone are compared with those of pioglitazone--the other thiazolidinedione currently available in the United States. Edema of mild to moderate severity has been reported in approximately 5% of patients treated with rosiglitazone during clinical trials. Therefore, caution must be taken when this agent is administered to patients with heart failure. Rosiglitazone has also been associated with elevations of total, LDL, and HDL cholesterol during clinical trials. However, the LDL:HDL cholesterol ratio or the total:HDL cholesterol ratio has mostly been observed to be unchanged. Although liver toxicity has not been observed with rosiglitazone during clinical trials, the safety of this drug for long-term usage and in larger patient populations remains to be established in further clinical studies and in postmarketing experience.

Diabetes Mellitus, Type 2↗