Long-term safety and efficacy of combination gemfibrozil and HMG-CoA reductase inhibitors for the treatment of mixed lipid disorders

BACKGROUND

Combinations of gemfibrozil and a 3-hydroxy-3-methylglutaryl (HMG) coenzyme A reductase inhibitor show promise in treating mixed lipid abnormalities. However, concern regarding the risk of myopathy and hepatic toxicity has limited the use of this combination. To determine the long-term safety and efficacy of this combination, we prospectively identified all patients placed on a combination of gemfibrozil and any HMG reductase inhibitor.

METHODS

Pravastatin, simvastatin, fluvastatin, lovastatin, or atorvastatin at incremental doses was combined with gemfibrozil (600 mg twice daily). Lipid profiles, creatine kinase levels, and aminotransferase levels were monitored. Two hundred fifty-two patients with established atherosclerosis receiving combination therapy for a mean of 2.36 +/- 1.52 years spanning a total of 593.6 patient-years were monitored.

RESULTS

In 148 patients, gemfibrozil was started before an HMG was added. The pretreatment total cholesterol level fell from 222 +/- 34 mg/dL to 181 +/- 26 mg/dL (P <.001) on combination therapy. HDL cholesterol level rose from 30 +/- 5 mg/dL to 36 +/- 7 mg/dL (P <.01), triglyceride level fell from 361 +/- 141 mg/dL to 212 +/- 101 mg/dL (P <.03). The ratio of total cholesterol to HDL fell from 7.6 +/- 1. 7 to 5.3 +/- 1.6 (P <.001). In 104 patients an HMG was begun before gemfibrozil was added. Pretreatment total cholesterol level fell from 246 +/- 54 mg/dL to 192 +/- 40 mg/dL on combination therapy (P <.01). HDL level rose from 33 +/- 9 mg/dL to 38 +/- 9 mg/dL (P <.03) and triglyceride level fell from 314 +/- 183 mg/dL to 183 +/- 93 mg/dL (P <.001). The ratio of total cholesterol to HDL fell from 7.9 +/- 3.6 to 5.2 +/- 1.4 (P <.001). In both groups the lipid profile on combination therapy was significantly better than that obtained on single-agent therapy. One episode of myopathy (0.4%) and one episode of aminotransferase level elevation (0.4%) of greater than 3 times upper limit of normal occurred. Both resolved with cessation of therapy without consequence.

CONCLUSIONS

Combinations of gemfibrozil and an HMG, compared with either agent alone, results in improved long-term control of lipid abnormalities in mixed lipid disorders. The low incidence of toxicity permits the use of combination therapy in patients at high risk of atherosclerotic complications.

Diplopia in the emergency department

Normal binocular vision requires that all involved structures; ocular, muscular, and neuronal; be intact and all of the intricate processes controlling conjugate gaze and cortical fusion be functioning. Diplopia may represent pathology at any point in this complex system. A careful history and physical examination may reveal a relatively benign etiology or may compel rapid diagnostic studies to evaluate the patient for neurological catastrophe.

Liquid chromatographic determination of thiamine in infant formula products by using ultraviolet detection

A liquid chromatographic (LC) method has been developed for determination of thiamine in infant formula products. The method involves the following steps: (a) dissolution of the formula with water, (b) pH adjustment to induce protein precipitation, (c) filtration, (d) concentration of thiamine by using a cation exchange column and extraction system, (e) cleanup of adsorbed thiamine and other contaminants on the ion exchange column by washing with water and then methanol, (f) elution of thiamine with a mixture of methanol-2M potassium chloride buffer, (g) analysis for thiamine by liquid chromatography. Thiamine is separated from its phosphate esters, the mono-, di-, and triphosphates, as well as its antagonists oxythiamine and pyrithiamine on a 6 micron particle size column and a mobile phase of 40mM triethyl-ammonium phosphate buffer-methanol (pH 7.7) (90 + 10). The method is reproducible, with relative standard deviations ranging from +/- 0.76 to +/- 1.2%, depending on the infant formula product tested. Recovery of thiamine from various infant formula products is greater than 99%. Analysis for thiamine of several commercially available infant formulas at different levels of fortification gave results that ranged from 122 to 216% of the declared levels. These results agree well with those obtained using the AOAC fluorometric method.