Impact of a limited fluoroquinolone reimbursement policy on antimicrobial prescription claims.

OBJECTIVE: To examine the influence on administrative pharmacy claims of a policy that limited the reimbursement of the fluoroquinolones and other antimicrobials in the senior population within Nova Scotia, Canada. METHODS: The administrative claims database of the Nova Scotia Seniors' Pharmacare Program was used to identify all prescription claims for orally administered antibiotics and urinary antiinfectives. The number of beneficiaries receiving antimicrobials and the number, duration, and cost of prescriptions for antimicrobials were measured monthly. Descriptive time-series plots were used to compare antimicrobial use for two 12-month periods before the institution of the policy (December 1, 1994-November 30, 1995, and December 1, 1995-November 30, 1996) and the 12 months after the policy took effect (January 1, 1997-December 31, 1997). RESULTS: Following the implementation of the fluoroquinolone reimbursement policy, the number of patients using antimicrobials decreased by 2.2% and the number of prescriptions for antimicrobials decreased by 3.4%. Fluoroquinolone prescriptions decreased by 80.2%; prescriptions for sulfonamides and trimethoprim increased by 34.9%, cephalosporins by 17.0%, and macrolides and lincosamides by 16.5%. The only prescription duration to change was the fluoroquinolones, which increased by 25%. The average cost per antimicrobial user/year decreased from $35.24 during prepolicy period 2 to $27.51 during the postpolicy period. CONCLUSIONS: Prescription claims for fluoroquinolones in seniors decreased following the introduction of the policy. Total antimicrobial use also decreased, although this may be related to other factors. The effect of this policy change on patient outcomes requires further study.

Acid neutralization capacity of Canadian antacid formulations.

A study was designed to determine the acid neutralization capacities (ANCs) of the new Canadian antacid formulations and to compare these products with standard antacid products in terms of lot-to-lot consistency, ANC, sodium and "calorie" contents, and price to the pharmacist. Twenty-three liquid and 18 tablet antacids were tested. The concentrated liquid antacids (Mylanta-2 Extra Strength, Amphojel 500, Gelusil Extra Strength, Maalox TC and Diovol Ex) were found to have the highest ANCs. Six of the tablet antacids (Amphojel, Amphojel Plus, Camalox, Gelusil-400, Maalox and Mylanta-2) were found to have greater ANCs than 15 of the liquid antacids. Between-lot variation exceeded that of within-lot variation in 10 of the 14 liquid antacids for which this variation could be tested. The concentrated liquid antacids provide the highest ANCs with the lowest dosage volume and sodium and calorie contents. Some tablet antacids have the potential to be used as alternatives to liquid antacids because of their high ANC and patient convenience. The inclusion of ANC on the labels of antacid products would assist in the rational determination of the dose of these products.

Is there a problem with benzodiazepine prescribing in maritime Canada?

The benzodiazepine prescribing habits of 64 maritime doctors were studied through collection and examination of carbon copies of all prescriptions over a 22 week period. Diazepam was the most frequently prescribed anxiolytic benzodiazepine, followed by chlordiazepoxide, then oxazepam. These three drugs accounted for almost 60% of all benzodiazepine prescriptions. Triazolam and flurazepam were prescribed eight times more frequently than the other hypnotics, nitrazepam and temazepam. The number of prescriptions judged to be inappropriately excessive was small (3.3% of 7,066). Efforts by drug manufacturers, pharmaceutical sales representatives and CME providers are needed to make the practicing physician aware of the phamacokinetics of the different benzodiazepines, so that an appropriate choice of drug and frequency of daily doses can be made.

In vitro effect of new penicillins and aminoglycosides on tests for glycosuria.

The effect of newer penicillins (azlocillin, mezlocillin, cyclacillin, and piperacillin) a 6 beta-amidinopenicillanic acid derivative (amdinocillin), and newer aminoglycosides (netilmicin and sisomicin) on the accuracy of tests for glycosuria was studied. Solutions of each of the drugs were prepared in urine in a range of clinically obtainable drug concentrations. In addition, urine solutions were prepared that contained the same drug concentrations and 0.5, 1, and 2% glucose. All solutions were tested in triplicate using the five-drop Clinitest method and two glucose oxidase methods (Diastix and Tes-Tape). Falsely elevated Clinitest readings of approximately 0.25% were obtained with the penicillins. These readings were influenced by the concentration of the penicillins and of glucose. Neither amdinocillin nor the aminoglycosides had an effect on Clinitest determinations. None of the drugs interfered with Diastix or Tes-Tape readings. Because the Clinitest-penicillin interaction is unpredictable, Clinitest results should be rechecked using one of the qualitative glucose oxidase tests when Clinitest is used as a quantitative test for glycosuria in patients receiving penicillins. All three tests studied can be used to test for glycosuria in patients receiving amdinocillin or one of the aminoglycosides.

Extravasation: a hazard of intravenous therapy.

Tissue damage due to extravasation does not occur frequently, but the consequences can be severe. Certain factors are important in determining the likelihood of extravasation injury. These include the age, state of consciousness, and venous circulation of the patient and the type, location, and placement of the intravenous cannula. Extravasation injury is induced most frequently by drugs that have high osmolalities, vesicant properties, or the ability to induce ischemia. Treatment includes elevation of the extremity, application of heat or cold, and the administration of an appropriate antidote. Prevention of extravasation injury requires recognition of potentially hazardous drugs and good technique in administering drugs intravenously.

Tartrazine: a potentially hazardous dye in Canadian drugs.

The literature was reviewed to determine the incidence of idiosyncratic reactions to tartrazine. From 4% to 14% of individuals with asthma or allergies or both and from 7% to 20% of persons who are sensitive to acetylsalicylic acid may react to this dye. The mechanism of such reactions is unknown. Pharmaceutical manufacturers and distributors were surveyed and a list was prepared of approximately 450 Canadian pharmaceuticals that contain tartrazine. The 53 pharmaceutical and manufacturers and distributors whose drug products do not contain this dye were also listed. It is recommended that information concerning the tartrazine content of drugs be included on package labels.

In vitro effect of penicillins and aminoglycosides on commonly used tests for glycosuria.

The effect of penicillins (ampicillin, carbenicillin, penicillin G, and penicilloic acid) and aminoglycosides (amikacin, gentamicin, streptomycin, and tobramycin) on the accuracy of Clinitest, Diastix, and TesTape determinations of glycosuria was studied. Solutions of each of the drugs were prepared in urine in a range of clinically obtainable drug concentrations. In addition, urine solutions were prepared that contained the same drug concentrations and sufficient glucose to give final concentrations of 0.5, 1, and 2%. All solutions were tested in triplicate using the five-drop Clinitest method, Diastix, and TesTape. Falsely elevated and falsely decreased Clinitest readings were obtained with the penicillins. These readings were influenced by the concentration of the penicillins and of glucose. The aminoglycosides had no effect of Clinitest determinations. Neither drug class interfered with Diastix or TesTape readings. The Clinitest-penicillin interaction is unpredictable. If Clinitest is used as a quantitative test for glycosuria in patients receiving penicillins, the results should be rechecked using a qualitative method such as the glucose oxidase tests, Diastix or TesTape. All three tests can be used to test for glycosuria in patients receiving aminoglycosides.

Compatibility of diazepam with intravenous fluid containers and administration sets.

The effect of i.v. containers (plastic and glass) and plastic administration sets (with and without inline filters) on diazepam availability was studied. Solutions (50 mg diazepam/500 ml fluid and 25 mg/500 ml) of diazepam in dextrose 5% in water and lactated Ringer's injection were stored in glass i.v. bottles or plastic burette chambers and then infused (2.5 and 5 mg/hr) through plastic i.v. administration sets with or without 0.45-micron inline filters. Concentrations of the solutions were measured spectrophotometrically after two and four hours in the containers and in the administration sets. Solutions were inspected visually for compatibility, and pH was measured. No visual incompatibilities were observed, and pH remained constant. Solutions stored in glass bottles and infused through plastic sets retained greater than 90% of initial potency after four hours. Solutions stored in plastic burette chambers and administered through plastic sets lost greater than 38% of potency after two hours; the loss occurred principally in the plastic chamber and increased with increasing drug concentration and time. Drug availability was not affected by type of i.v. fluid, pH, flow rate, or filtration. If diazepam is to be infused, it should be diluted to at least a 1:10 dilution in glass i.v. bottles and administered through plastic administration sets not having burette chamgers. Inline filters (0.45 micron) may be used without a loss of potency.