Pharmacy counselling models: a means to improve drug use.

BACKGROUND AND OBJECTIVE: Failure to achieve the intended benefit of medical treatment is recognized as an immense problem. The study objective was to examine the usefulness of counselling models containing key questions to facilitate the identification of drug-related problems (DRPs), and to follow up on both pharmacy practitioner and patient experiences. METHODS: Fifty-one pharmacies in Sweden were recruited, along with matching controls. Patients of six therapeutic groups were selected for the counselling model intervention. DRPs were documented in the Swedish DRP database. A telephone follow-up with the patients and a questionnaire survey with the pharmacy practitioners were conducted. An additional follow-up was made in patients sending a representative to pick up their prescribed medications at the pharmacy. RESULTS AND DISCUSSION: In all, 880 DRPs were documented in patients with 8100 prescriptions (10·9%). The DRP documentation rates in study pharmacies were, in general, superior to the control pharmacy rates. DRPs were identified in 24·8% of the non-steroidal anti-inflammation drug (NSAID) patients using a representative to pick up their medications, compared with 9·2% in patients visiting the pharmacy themselves. Of the patients who took part in the follow-up, 94% said that they received suggestions on problem resolution, and twice as many DRPs were reported resolved vs. unresolved. Most patients and pharmacy practitioners were pleased with the new practice. CONCLUSION: The practice of counselling models appears to be a means to improve drug use. More DRPs were found in patients sending a representative to pick up their medications than in patients visiting the pharmacy themselves.

Correlation of human jejunal permeability (in vivo) of drugs with experimentally and theoretically derived parameters. A multivariate data analysis approach.

The effective permeability (Peff) in the human jejunum (in vivo) of 22 structurally diverse compounds was correlated with both experimentally determined lipophilicity values and calculated molecular descriptors. The permeability data were previously obtained by using a regional in vivo perfusion system in the proximal jejunum in humans as part of constructing a biopharmaceutical classification system for oral immediate-release products. pKa, log P, and, where relevant, log Pion values were determined using the pH-metric technique. On the basis of these experiments, log D values were calculated at pH 5.5, 6.5, and 7.4. Multivariate data analysis was used to derive models that correlate passive intestinal permeability to physicochemical descriptors. The best model obtained, based on 13 passively transcellularly absorbed compounds, used the variables HBD (number of hydrogen bond donors), PSA (polar surface area), and either log D5.5 or log D6.5 (octanol/water distribution coefficient at pH 5.5 and 6.5, respectively). Statistically good models for prediciting human in vivo Peff values were also obtained by using only HBD and PSA or HBD, PSA, and CLOGP. These models can be used to predict passive intestinal membrane diffusion in humans for compounds that fit within the defined property space. We used one of the models obtained above to predict the log Peff values for an external validation set consisting of 34 compounds. A good correlation with the absorption data of these compounds was found.