Cost comparison of tinzaparin versus enoxaparin as deep venous thrombosis prophylaxis in spinal cord injury: preliminary data.

Thromboembolic events are major causes of morbidity and mortality in patients with spinal cord injuries. Low molecular weight heparins are recommended as prophylaxis against such events. The purpose of the current study was to perform a cost analysis of tinzaparin versus enoxaparin using published efficacy and safety data as deep vein thrombosis and pulmonary embolism prophylaxis in this population. All published English language articles evaluating either tinzaparin or enoxaparin as pharmacoprophylaxis in spinal cord-injured patients were identified. Data from these studies were subjected to cost-effectiveness analyses followed by sensitivity analyses to determine which agent is the most cost-effective in these patients. Results demonstrated that tinzaparin 3500 U daily and enoxaparin 30 mg every 12 h are both cost-effective agents for thromboembolism prophylaxis in patients with spinal cord injuries.

Three Michaelis-Menten pharmacokinetic dosing methods compared with physician dosing of phenytoin in an outpatient neurology practice.

We compared predicted phenytoin serum concentrations using three Michaelis-Menten pharmacokinetic dosing methods with actual concentrations obtained from physician dosing in an outpatient neurology practice. Method 1 used population estimates for the Michaelis-Menten constant (Km) and maximum velocity (Vmax), method 2 used one dose and serum concentration pair to determine Vmax, and method 3 used two dose-concentration pairs to determine both Km and Vmax. In addition, physician doses were compared with pharmacokinetically calculated doses. Records of patients who received at least two phenytoin doses followed by two serum concentration determinations were reviewed. Data on age, gender, weight, physician doses, and resultant serum concentrations were collected. Pearson's correlation coefficient was used to compare physician maintenance doses with pharmacokinetically calculated predicted doses, whereas actual and predicted serum concentration data were used to determine precision and bias associated with each of the three methods. Actual serum concentrations fell into therapeutic range more frequently than predicted values in all but one comparison (method 3). Predicted and actual phenytoin doses were significantly correlated only with method 2. Only one of the three Michaelis-Menten pharmacokinetic dosing methods evaluated (method 3) was more predictive than physician phenytoin dosing.

Improved health-related quality of life with SSRIs and other antidepressants.

STUDY OBJECTIVE: To document the health-related quality of life (HRQOL) of depressed patients receiving antidepressant drugs. DESIGN: Cross-sectional study. SETTING: Community pharmacy-based setting. PATIENTS: Fifty-seven depressed patients. INTERVENTION: Independent pharmacist members of the Community Pharmacists Research Network in Georgia administered the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) to subjects. MEASUREMENTS AND MAIN RESULTS: Sixty-one percent of patients were treated with a selective serotonin reuptake inhibitor (SSRI) and 38.6% were treated with a non-SSRI. Those receiving SSRIs scored higher on the mean physical (PCS) and mental (MCS) health summary scores of the SF-36 than those not receiving the drugs. No significant differences were seen in PCS or MCS scores of men and women. CONCLUSION: Community pharmacists documented better HRQOL in patients receiving SSRIs than in those given other antidepressants.

Achievement of anticoagulation by using a weight-based heparin dosing protocol for obese and nonobese patients.

The need for different heparin dosing protocols for obese and nonobese patients was studied. A chart review was performed for all patients who received heparin over an eight-month period at an acute care hospital. Data collected included age, sex, height, actual body weight (ABW), ideal body weight (IBW), initial activated partial thromboplastin time (aPTT), initial heparin bolus dose, initial heparin i.v. infusion rate, time to initial targeted aPTT, and final infusion rate. Forty patients met criteria for inclusion: 20 obese patients (greater than 30% over IBW) and 20 nonobese patients (less than 20% over IBW). Mean +/- S.D. initial heparin infusion rates for the obese and nonobese groups were 14.44+/-1.29 and 15.04+/-0.42 units/kg/hr, respectively. Times to targeted aPTT for obese and nonobese patients were 25.86+/-12.83 and 25.18+/-14.76 hours, respectively; mean final infusion rates were 12.94+/-2.56 and 12.36+/-2.54 units/kg/hr; and percent changes from initial to final infusion rates were 11.84% and 17.76%. There were no significant differences in initial or final infusion rates or time to targeted aPTT between the two groups. It is appropriate to use ABW in a weight-based heparin dosing protocol for obese patients.

Formulary management of low molecular weight heparins.

Low molecular weight heparins (LMWHs) are increasingly being utilised as anticoagulants in healthcare settings. These agents offer several advantages over standard unfractionated heparin. Indications for LMWHs include deep vein thrombosis and pulmonary embolism prophylaxis, deep vein thrombosis treatment, use in coronary procedures associated with a high risk for bleeding, and in acute coronary syndromes. Prior to being added to formularies, LMWHs should be evaluated for efficacy, safety and economic benefits over other anticoagulants. Institutions should be prepared to conduct their own economic assessments in the absence of readily available studies. There is clear evidence that LMWHs are cost saving or are at least cost effective as thromboprophylactic agents in major orthopaedic surgery. The economic benefits of LMWHs in other surgical situations is less clear. Consistent evidence from several countries indicate that LMWHs are cost saving as anticoagulants for the initial treatment of DVT. Further studies are needed to evaluate the efficacy, safety and economics of LMWHs in other conditions besides hip and knee arthroplasty and general surgery.

Cost analysis of the American College of Chest Physicians guidelines for deep vein thrombosis prophylaxis in patients undergoing orthopedic arthroplastic surgery.

Guidelines for prophylaxis of deep vein thrombosis secondary to orthopedic surgery have been developed. In selecting a specific drug for formulary inclusion, it is ideal for an individual institution to determine the cost of therapy, as well as the frequency of adverse events and the cost of treating them for each agent undergoing consideration. Cost-effectiveness analysis using incremental cost-effectiveness ratios and sensitivity analyses are useful for determining which drug may be most cost effective.

The expanding role of pharmacy and therapeutics committees. The 1990s and beyond.

Traditionally, pharmacy and therapeutics (P&T) committees have been responsible for overseeing the drug use process, using formulary systems to control drug costs. Primarily, these committees act in an advisory capacity as policy-recommending bodies within healthcare systems, for the specific purpose of promoting rational drug therapy. Methodologies utilised by these committees include drug use evaluation, medical staff education, continuous quality improvement, formulary restriction and therapeutic interchange. Future roles of P&T committees will include the evaluation of clinical outcomes information, including quality-of-life issues, to establish policies governing the use of drugs at all levels and in all types of healthcare.

Depression associated with antihypertensive drugs.

BACKGROUND: Depression is a potential side effect of antihypertensive drug therapy. Consideration of this side effect is a reason often cited by physicians for not choosing certain drugs. METHODS: In this prospective study the relative rates of depression were measured by the Zung Self-Rating Depression Scale (SDS) in patients from four hypertension treatment groups. Treatment groups consisted of 466 patients receiving: (1) no drug therapy, (2) diuretics only, (3) diuretics plus reserpine, and (4) diuretics plus beta-blockers. Demographic data including age, sex, and race were collected. Analysis of variance was used to compare the rate of depression among the treatment groups, as well as among age, sex, and racial groups. RESULTS: Using a Zung SDS index of greater than or equal to 50, 35.4% of the hypertensive population was depressed. Age and sex were not significant factors in the frequency of depression. Blacks scored higher than whites in all drug treatment groups except those treated with high lipophilic beta-blockers, but the rate of depression was not higher. Whites on the lowest dose of reserpine had the lowest rate of depression. The rate of depression among those taking reserpine or beta-blockers was no different than that among those receiving either no treatment or diuretics. CONCLUSIONS: Reserpine or beta-blocker therapy did not cause any more depression than any other antihypertensive treatment.

Pharmacokinetics of methotrexate administered by intramuscular and subcutaneous injections in patients with rheumatoid arthritis.

The serum concentrations and the pharmacokinetics of low-dose methotrexate (MTX) were compared after both intramuscular (IM) and subcutaneous (SQ) injections in 5 patients with rheumatoid arthritis. Values for the observed peak concentration, the time to the observed peak concentration, and the area under the time versus concentration curve for IM injections were not significantly different from these values for SQ injections. These results suggest that IM and SQ are interchangeable routes of administration. SQ administration may be a more convenient and less painful way of administering low-dose MTX.

The use of aerosolized tobramycin in the treatment of a resistant pseudomonal pneumonitis.

Aerosolized tobramycin was given to a 68-year-old man with resistant Pseudomonas aeruginosa pneumonitis at a dose of 100 mg every 8 h via a tracheostomy, after the patient failed to respond adequately to parenteral aminoglycoside and ticarcillin therapy. Minimum inhibitory concentration and minimum bactericidal concentration for tobramycin and gentamicin were 16 micrograms/ml and greater than 16 micrograms/ml, which necessitated aerosol administration. Tracheal concentrations 15 min and 4 h after a dose were 1,560 and 930 micrograms/ml. The patient responded and eventually was discharged from the hospital. Thus, monotherapy with an aerosolized aminoglycoside may be effective in some patients with resistant Pseudomonas aeruginosa pneumonitis.

Lack of theophylline assay interference from pentoxifylline and its metabolites.

Pentoxifylline, a hemorheologic agent, and its metabolites are structurally similar to theophylline and other xanthines; therefore, they have the potential to interfere with serum assays for theophylline. Any false elevation of theophylline serum concentrations could have a significant impact on drug therapy decisions. Serum was obtained from six elderly subjects who had been taking 400 mg of pentoxifylline three times daily for at least six months. A serum assay using the TDx fluorescence polarization immunoassay failed to detect any measurable amount of theophylline. Normal doses of pentoxifylline and the resulting metabolites do not appear to interfere with the TDx method of serum assay for theophylline.

In vitro inactivation of tobramycin by cephalosporins.

The in vitro inactivation of tobramycin when combined with each of six cephalosporins in samples of human serum was investigated. Each of six cephalosporins (cefazolin sodium, cefoxitin sodium, cefamandole nafate, moxalactam disodium, cefoperazone sodium, and cefotaxime sodium) was added to human serum samples containing tobramycin sulfate 8 micrograms/mL to produce final cephalosporin concentrations of approximately 250 and 1000 micrograms/mL. Duplicate solutions were prepared and stored at either 0 or 21 degrees C. Solutions containing tobramycin 8 micrograms/mL alone and with carbenicillin disodium in four concentrations were prepared as controls. Samples were assayed using a fluorescence polarization immunoassay (TDX) at 0, 2, 4, 8, 12, 24, and 48 hours to determine tobramycin concentration; two of the carbenicillin-tobramycin solutions were frozen immediately for assay 53 hours later. Tobramycin concentrations in the admixtures were compared with those in tobramycin reference samples. At both temperatures, samples containing tobramycin with cefamandole 250 micrograms/mL or cefotaxime 250 micrograms/mL showed less than 10% inactivation of tobramycin for at least 48 hours. At 0 degrees C, tobramycin retained greater than 90% activity when combined with cefoperazone 250 and 1000 micrograms/mL. In samples containing cefazolin 250 micrograms/mL at 0 degrees C and cefoperazone 250 micrograms/mL at 21 degrees C, tobramycin was stable for 24 hours. Only samples containing moxalactam stored at 21 degrees C showed greater than 16% inactivation of tobramycin at 48 hours. Under these study conditions, tobramycin is only moderately inactivated in vitro when combined with clinically achievable concentrations of the tested cephalosporins (excluding moxalactam) and then stored for up to 48 hours.(ABSTRACT TRUNCATED AT 250 WORDS)