Health care utilization in patients with migraine: demographics and patterns of care in the ambulatory setting.

BACKGROUND: Migraine affects people of all races and both sexes. Migraineurs suffer both financial losses and impaired quality of life. Recent progress in the treatment of migraine has not been made readily available to all who suffer the condition. OBJECTIVE: To assess outpatient health care delivery patterns for migraine sufferers in the United States. METHODS: National Ambulatory Medical Care Survey data from 1990 to 1998 was used to assess the demographics of patients seen with a diagnosis of migraine, the types of physicians they saw, and the medications used to treat migraine. RESULTS: Women accounted for 79% of visits for migraines and whites for 91% of the visits. There was a dramatic increase in the number of migraine visits during the study period, from 9.4 visits per 1000 people in 1990 to 18 visits per 1000 in 1998. Primary care physicians saw the majority of patients (72.2%). Butalbital ( Fioricet )/aspirin/caffeine was the drug most commonly prescribed for migraine treatment, followed by acetaminophen/dichloralphenazone/isometheptene mucate, propranolol, and sumatriptan. CONCLUSION: Perhaps in part due to newer treatment options, the number of visits for the treatment of migraine doubled over the study interval. Even so, most patients with migraine continue to be treated with older and presumably less effective medications.

Mechanistic studies on the use of 2H- and 13C-analogues as internal standards in selected ion monitoring GC-MS quantitative determination--Butalbital ( Fioricet ) example.

As a part of our study on the use of isotopic analogues as the internal standard (IS) for the quantitation of drug analytes, this article reports on the performance characteristics of 2H5-Butalbital ( Fioricet ) and 13C4-Butalbital ( Fioricet ) with particular focus on (1) determining and comparing the effectiveness of the 2H- and 13C-analogues in serving as the ISs for quantitation; (2) understanding the "cross-contribution" phenomenon underlying the effectiveness of selected ion pairs used for quantitation purpose; and (3) examining whether the same characteristics, observed in our preliminary report for the secobarbital/2H5-secobarbital/13C4-secobarbital system, also exist in the Butalbital ( Fioricet )/2H5-Butalbital ( Fioricet )/13C4-Butalbital ( Fioricet ) system. Adapting similar procedures applied to our previous study on the secobarbital system, we observed that (1) both labeled analogues (13C4-Butalbital ( Fioricet ) and 2H5-Butalbital ( Fioricet )) cause more significant cross-contributions to ions designated for Butalbital ( Fioricet ) than Butalbital ( Fioricet ) to the labeled analogues; (2) compared to 2H5-Butalbital ( Fioricet ), 13C4-Butalbital ( Fioricet ) appears to cause less cross-contributions to ions designated for Butalbital ( Fioricet ); (3) cross-contribution between the following ion pairs are minimal: m/z 200/196, 199/195, 185/181 (13C4-Butalbital ( Fioricet ) as the IS) and m/z 201/196 (2H5-Butalbital ( Fioricet ) as the IS). It is also concluded that the Butalbital ( Fioricet )/2H5-Butalbital ( Fioricet ) system exhibits the same concentration dependency phenomenon observed in the secobarbital/ 2H5-secobarbital system, that is, ratios of ion pairs designated for these two isotopic analogues (resulting from routine gas chromatography-mass spectrometry protocol) increase as their concentrations are diluted. (In parallel with the secobarbital/13C4-secobarbital system, the Butalbital ( Fioricet )/13C4-Butalbital ( Fioricet ) system does not exhibit this phenomenon.)

Isotopic analogues as internal standards for quantitative analyses of drugs and metabolites by GC-MS--nonlinear calibration approaches.

In order to achieve accurate quantitation of drugs and metabolites (analytes) in complex matrices, 2H- (and less commonly 13C-) labeled analogues of the analytes are now routinely adapted as the internal standards (IS) using linear calibration models to fit data generated by selected ion monitoring gas chromatography-mass spectrometry (GC-MS) protocols. In this study, the effects of cross-contribution (contribution of the IS to the intensity of the ion designated for the analyte and vice versa) on the linearity of the calibration data are examined. Nonlinear approaches that may address this problem are also studied. Two ion pairs (one with least and one with significant cross-contribution) from each of the following analyte/IS pairs are used as the exemplar systems for this study: Butalbital ( Fioricet )/13C4-Butalbital ( Fioricet ), Butalbital ( Fioricet )/2H5-Butalbital ( Fioricet ), secobarbital/13C4-secobarbital, and secobarbital/2H5-secobarbital. Analyte/IS ion intensity ratios of a series of standard solutions are correlated with the analyte/IS concentration ratios using one-point, multiple-point (unweighted and weighted) linear, and hyperbolic functions. The one-point calibration approach produces excellent calibration results in treating data derived from ion pairs with no significant cross contribution. In cases where significant cross-contribution exists, results derived from the one-point approach show, as expected, significant deviations at both ends of the concentration range. With the cross-contribution phenomenon accounted for, the hyperbolic calibration model is clearly more effective in fitting calibration data at both the lower and higher analyte concentration ends, thus significantly lowering the detection limit and extending the calibration range to a higher level. However, the calibration range cannot be extended indefinitely. At the low concentration end, noise-to-signal ratio and the cross-contribution of the IS to the intensity of the ion designated for the analyte, however insignificant, will incrementally reduce the quality of the observed ion intensity and intensity ratio data. At the high concentration end, detection saturation and the cross-contribution of the analyte to the intensity of the ion designated for the IS, however insignificant, will incrementally decrease the "slope" of the calibration curve. Thus, acceptable sensitivity (increase in analyte/IS ion-pair intensity ratio per unit increase in analyte concentration) of the calibration curve will become the limiting factor.

GC/MS confirmation of barbiturates in blood and urine.

A gas chromatography-mass spectrometric method is described for the quantitative measurement of 6 commonly used barbiturates in blood and urine specimens. The targeted barbiturates are Butalbital ( Fioricet ), amobarbital, pentobarbital, secobarbital, mephobarbital and phenobarbital. They are recovered along with the internal standard, tolybarb, from blood and urine using liquid extraction then alkalated to form the N-ethyl derivatives. The ethylated barbiturates have symmetrical peaks which are well separated from each other on a non-polar methylsilicone capillary column.