Pharmacokinetic drug-drug interaction and their implication in clinical management.

Drug-drug interactions (DDIs) are one of the commonest causes of medication error in developed countries, particularly in the elderly due to poly-therapy, with a prevalence of 20-40%. In particular, poly-therapy increases the complexity of therapeutic management and thereby the risk of clinically important DDIs, which can both induce the development of adverse drug reactions or reduce the clinical efficacy. DDIs can be classify into two main groups: pharmacokinetic and pharmacodynamic. In this review, using Medline, PubMed, Embase, Cochrane library and Reference lists we searched articles published until June 30 2012, and we described the mechanism of pharmacokinetic DDIs focusing the interest on their clinical implications.

The Risk of Drug Interactions in Older Primary Care Patients after Hospital Discharge: The Role of Drug Reconciliation.

INTRODUCTION: Drug-drug interactions (DDIs) represent an important clinical problem, particularly in older patients, due to polytherapy, comorbidity, and physiological changes in pharmacodynamic and pharmacokinetic pathways. In this study, we investigated the association between drugs prescribed after discharge from the hospital or clinic and the risk of DDIs with drugs used daily by each patient. METHODS: We performed an observational, retrospective, multicenter study on the medical records of outpatients referred to general practitioners. DDIs were measured using the drug interaction probability scale. Potential drug interactions were evaluated by clinical pharmacologists (physicians) and neurologists. Collected data were analyzed using the Statistical Package for the Social Sciences. RESULTS: During the study, we evaluated 1772 medical records. We recorded the development of DDIs in 10.3% of patients; 11.6% of these patients required hospitalization. Logistic regression showed an association among DDIs, sex, and the number of drugs used (p = 0.023). CONCLUSIONS: This observational real-life study shows that the risk of DDIs is common in older patients. Physicians must pay more attention after hospital discharge, evaluating the treatment to reduce the risk of DDIs.

Is there a Link between Non Melanoma Skin Cancer and Hydrochlorothiazide?

AIMS: Here in we evaluated the association between the use of Hydrochlorothiazide (HCTZ) and the risk of NMSC both, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). BACKGROUND: Even though the use of HCTZ is not linked with the development of serious adverse drug reactions, non-melanoma skin cancer (NMSC) has been reported in patients treated with the drug in recent years, most likely due to its photosensitizing ability. OBJECTIVE: To evaluate the statistically significant difference (P<0.05) in the development of NMSC between HCTZ users and non-users and the correlation (P<0.05) between HCTZ use and NMSC. METHODS: We performed a retrospective study on patients referred to general practitioners who developed skin cancer or NMSC whether or not they were treated with antihypertensive drugs. Controls were matched with the test by age and sex. We calculated odds ratios (ORs) for skin cancer and NMSC associated with hydrochlorothiazide using conditional logistic regression. RESULTS: We enrolled 19,320 patients in the present study, out of a total of 10,110 (52.3%) who were treated with antihypertensive drugs. Of 10,110 patients, 3,870 were treated with HCTZ (38.3%). During the study, we failed to report an increased risk of NMSC in HCTZ-treated vs. untreated patients. Gender stratification revealed an OR for NMSC of 1.36 for men and 0.56 for women. We did not find a dose-response relationship between HCTZ use and NMSC. CONCLUSION: In the present study, we failed to report an association between the use of HCTZ and the development of NMSC.

Anti-vascular endothelial growth factor drugs safety and efficacy in ophthalmic diseases.

Macular degeneration is the leading cause of blindness in developed countries. In the treatment of neovascular age-related macular degeneration, vascular endothelial growth factor (VEGF) has emerged as a key target for therapy. The intravitreal injection of anti-VEGF drugs has been widely employed to reduce the disease progression and improve the visual outcomes of the affected patients. However, each intravitreal inoculation poses a risk of several complications as infection, inflammation, endophthalmitis, intraocular inflammation, increase of intraocular pressure and vitreous hemorrhage. This short review evaluates the efficacy and the incidence of adverse drug reactions related to intravitreal administration of the main anti-VEGF drugs actually available: Bevacizumab, ranibizumab and aflibercept.