Evaluation of gastroprotectant administration in hospitalized cats in a tertiary referral hospital.

OBJECTIVES: The primary objective of this study was to evaluate the prescription patterns and appropriateness of the use of gastroprotectant medication in cats. METHODS: Pharmacy dispensation logs from an academic tertiary referral center were reviewed between 1 January 2018 and 31 December 2018. Cats that were administered proton pump inhibitors (PPIs), histamine-2 receptor antagonists (H2RAs), sucralfate, misoprostol, antacids or a combination were included. Data regarding medication, dosage, formulation, duration of administration, completeness of discharge instructions and clinical rationales for administration were obtained from medical records. The appropriateness of gastroprotectant use was assessed according to the American College of Veterinary Internal Medicine consensus statement guidelines. RESULTS: Of the 110 cases, 67 (60.9%) were prescribed a gastroprotectant medication without an appropriate indication. The most common reason for prescription was acute kidney injury in 26/67 (38.8%). PPIs were the most common gastroprotectant medication administered in 95/110 (86.3%) cats, followed by sucralfate in 18/110 (16.4%) and H2RAs in 11/110 (10%). Of the 35 cases in which gastroprotectant therapy was indicated, the medication chosen or dosage administered was considered suboptimal in 16 (45.7%). Instructions regarding the duration of administration, potential adverse effects and timing of administration in relation to meals or other medications were inconsistently provided in discharge instructions to pet owners. Of the 29 cases discharged with omeprazole, only 13 (44.8%) instructions included a duration of administration, while 6 (20.7%) recommended continuing gastroprotectants indefinitely until further notice, 16 (55.2%) discussed the timing of the administration in relation to a meal and six (20.7%) mentioned potential adverse effects; none advised tapering of omeprazole before discontinuation. CONCLUSIONS AND RELEVANCE: When prescribed, gastroprotectant medications were frequently prescribed injudiciously to cats in this referral population over a 12-month period. Discharge instructions to pet owners also often lacked information and recommendations regarding optimal administration, potential adverse effects, and tapering or discontinuation of the medications.

Assessing the urinary concentration of nitrofurantoin and its antibacterial activity against Escherichia coli, Staphylococcus pseudintermedius, and Enterococcus faecium isolated from dogs with urinary tract infections.

Nitrofurantoin, a broad-spectrum nitrofuran class antibiotic, is applied as a first-line antibiotic in treating human urinary tract infections (UTIs) due to its great efficacy and high achievable concentration. The interest in using this antibiotic in companion animals has increased due to the growing demand for effective antibiotics to treat UTIs caused by multidrug-resistant bacteria. Currently, the susceptibility interpretations for nitrofurantoin are based on the breakpoints set for humans, while the canine-specific breakpoints are still unavailable. In this study, we assessed the concentration of nitrofurantoin reaching the dog's urine using the recommended oral dosing regimen. In addition, we examined the efficacy of this breakpoint concentration against the common canine UTI pathogens, Escherichia coli, Staphylococcus pseudintermedius, and Enterococcus faecium. Eight experimental beagle dogs were treated with ~5 mg/kg of nitrofurantoin macrocrystal PO 8qh for 7 days. The urine samples were collected via cystocentesis at 2, 4, and 6 h after administration on day 2 and day 7 and used to quantify nitrofurantoin concentrations by ultra-high performance liquid chromatography. The results showed that 26.13-315.87 µg/mL nitrofurantoin was detected in the dogs' urine with a mean and median concentration of 104.82 and 92.75 µg/mL, respectively. Additionally, individual dogs presented with urinary nitrofurantoin concentrations greater than 64 µg/mL for at least 50% of the dosing intervals. This concentration efficiently killed E. coli, and S. pseudintermedius, but not E. faecium strains carrying an MIC90 value equal to 16, 16, and 128 µg/mL, respectively. Taken together, these results suggest that the value of 64 µg/mL may be set as a breakpoint against UTI pathogens, and nitrofurantoin could be an effective therapeutic drug against E. coli and S. pseudintermedius for canine UTIs.

Drug content on receipt and over time for compounded formulations of famciclovir.

OBJECTIVES: The aim of this study was to determine famciclovir content (strength) in compounded formulations and to determine if potency changed over time. METHODS: Four concentrations of oral oil suspension in three distinct flavors, three concentrations of oral paste, three chew treats and 62.5 mg tablets from one compounding pharmacy were evaluated for famciclovir content. Specific sample preparation procedures were used for each drug formulation prior to determination of famciclovir content through mass spectrometry tandem liquid chromatography. Analysis was performed on arrival from the compounder and on days 7, 14, 28, 56 and 120. Samples were run in triplicate and concentration determined by comparison with a standard curve. Content was considered appropriate if within 90-110% of the labeled concentration. RESULTS: On arrival from the compounding pharmacy, 5/12 oral oil suspensions of varying concentrations were <90% of the labeled concentration and 3/3 oral pastes were >110%. Famciclovir content in oil suspensions ranged from 72% to 118% of the label value while oral pastes ranged from 95% to 202% of the label concentration over the 120 study days, and all concentrations varied in an unpredictable fashion. Tablets contained 90-110% of the labeled value throughout the study period. Chew treats could not be successfully analyzed. CONCLUSIONS AND RELEVANCE: This study found substantial variation in famciclovir content in the compounded products evaluated, which, in turn, raises concerns that substandard dosing could result in lack of efficacy or a failed treatment trial. Drug toxicity might also be encountered. Veterinarians must be aware that while compounded medications can improve compliance, they might not deliver the drug dose expected.