Evaluation and assessment of prescribing patterns in elderly patients using two explicit criteria based screening tools: [the priscus list and stopp/start criteria]

Background and Objectives: Rational prescribing can prevent medication errors and the associated harm, especially in old age patients, as they are being frequently prescribed with drugs for various ailments .Moreover, polypharmacy is a common practice in them. Therefore, a significant threat of potential drug interactions and adverse effects exist. Current study focuses on assessment of Potentially Inappropriate Medication [PIM] in medication prescribed to old age patients

Methods: It was a forty days, descriptive and observational study conducted from August 15th 2017 to September 25th 2017 in which prescriptions given to elderly patients were reimbursed for collecting various sets of information. In order to assess PIMs [in Pakistani Set-up], STOPP/START addition 2008 [including examples of misprescribing, overprescribing and under prescribing] and the PRISCUS list [misprescribing and overprescribing] was used. Statistical analysis of results was performed using SPSS version 20

Results: One hundred forty six cases of PIMs [including incorrect prescribing, overprescribing and under prescribing] were detected. It included incorrect prescriptions 104, under prescription 28 and over prescriptions 14. NSAIDS accounted for most incorrect prescriptions followed by benzodiazepines. Mostly NSAIDS were used for myalgia, backache and rheumatoid disorders

Conclusion: Current findings highlighted Potentially Inappropriate Prescribing [PIP], particularly of NSAIDs and under prescribing of statins in cardiovascular diseases. Study findings suggest introducing pertinent interventions at the stages involved in prescribing, prescription review and its follow up to reduce the PIP and PIMs

Comparative pharmacokinetics of omeprazole and its metabolites in poor and extensive metabolizer Pakistani healthy volunteers and a review of different studies

This study was designed to evaluate a comparative single dose [40mg] pharmacokinetics [PK] of Omeprazole [OMP] and its two metabolites, 5-hydroxy Omeprazole [5-OH-OMP] and Omeprazole sulphone [OMP-S] in poor [PM] and extensive [EM] metabolizer Pakistani healthy adult volunteers. The frequency of CYP2C19 and CYP3A4 varies widely in different populations. The present study was conducted to evaluate the PK of OMP and its two metabolites in Pakistani population and to review different studies conducted after administration of single dose of OMP. Twenty two subjects were enrolled in this study and divided into two groups. The CYP2C19 phenotyping was evaluated by the metabolic ratio of OMP to 5-OH-OMP. It was a single dose, open label study and the blood samples from subjects were collected at different time intervals until 24 hours. The PK parameters were calculated using the PK-summit software. The metabolic ratio of area under the plasma concentration-time curve AUCOMP/5-OH-OMP was 1.86 +/- 0.572 and13.84 +/- 2.504 for EM and PM, respectively; maximum plasma concentration [Cmax] of OMP was increased by two folds for PM while the AUC? was increased by 3 folds; the Cmax and AUC? of 5-OH-OMP decreased for PM by 2 folds while there was 3 fold increase observed in the Cmax and AUC? of OMP-S. The PK of OMP and its metabolites in different populations were also discussed, and issues regarding CYP2C19 and CYP3A4 genotyping were also extensively reviewed. In EM of CYP2C19 the concentration of 5-OH-OMP is higher while that of OMP-S is lower. This study as well as reported studies reveals that in PM of CYP2C19 more drugs are available for CYP3A4 to be metabolized. A correlation between CYP2C19 EM and PM activity with CYP3A4 needs to be established

Variation in pharmacokinetics of omeprazole and its metabolites by gender and CYP2C19 genotype in Pakistani male and female subjects

Pharmacokinetics [PK] variation of drugs in males and females may affect therapeutic effectiveness and safety. In current study the PK differences for omeprazole and its metabolites5-hydroxy-omeprazole and omeprazole-sulphone were evaluated in males and females. The current study also considered PK comparison of Pakistani subjects using the CYP2C19 genotype as variable. A single oral dose [40mg omeprazole], open-labeland, non-controlled clinical trial was arranged. Samples were quantified using reversed phase HPLC-UV method. CYP2C19 genotype of subjects was determined by tetra primer polymerization chain reaction [PCR] assay. There was a significant increase in Cmax [from 2 to 2.9microg/ml, p=0.004], [from 6.67 to 8.74microg-hr/ml, p=0.05] and elimination half-life [from 1.05 to 2.1 hr, p=0.0001] of omeprazole in females compared with males. Cmax and of 5-hydroxy-omeprazole [0.0248 and 0.0001, respectively] and omeprazole-sulphone [0.0001 and 0.001, respectively] was significantly higher in females than males when compared at 95 onfidence interval. The Cmax and AUC of omeprazole showed a significant raise [p=0.01 and 0.04, respectively] in Homz PMs [Homozygous Poor Metabolizers] compared with Homz EMs [Homozygous Extensive Metabolizers] and Htrz PMs [Heterozygous Poor Metabolizers] while Cmax and AUC of 5-hydroxy-omeprazolewas significantly higher [p=0.01 and 0.04, respectively] in Homz EMs compared with Homz PMs and HtrzPMs. AUC of omeprazole was significantly higher in females while its elimination also took longer compared with males. AUC of omeprazole was significantly higher in Homz PMs indicating that CYP2C19 displayed genetically deficient metabolism in its homozygous state