The intestinal mucosa and liver have long been considered as the main sites of drug metabolism, and the contribution of gut microbiota to drug metabolism has been under-estimated. However, it is now generally accepted that the gut microbiota plays an important role in drug metabolism prior to drug absorption or during enterohepatic circulation via various microbial enzymatic reactions in the intestine. Moreover, some drugs are metabolized by gut microbiota to specific metabolite(s) that cannot be formed in the liver. More importantly, the metabolism of drugs by gut microbiota prior to absorption can alter the systemic bioavailability of certain drugs. Therefore, understanding drug metabolism by gut microbiota is critical for explaining changes in the pharmacokinetics of drugs, which may cause significant alterations in drug-induced pharmacodynamics and toxicities. In this review, we describe recent progress with regard to the role of metabolism by gut microbiota in some drug-induced alterations of either pharmacological or toxicological effects to emphasize the clinical importance of gut microbiota for safe and effective use of drugs.

Introduction: Hypertension (HTN) is a silent killer, accountable for life-threatening complications. An individual's illness perception may affect adherence to treatment which is crucial to prevent complications of HTN. The objective of this study was to identify illness perception and treatment adherence among patients with HTN in a tertiary hospital in Kathmandu, Nepal. Methods: Descriptive correlational study was conducted in the outpatient department of Manmohan Cardiothoracic Vascular and Transplant Center, Kathmandu Nepal. Nonprobability purposive sampling was used. A face-to-face interview was conducted from September to December 2018, using a structured questionnaire that included sociodemographic variables, illness perception questionnaire (revised) and Hill bone compliance to high blood pressure therapy scale. Data analysis was done by using descriptive and inferential statistics (chi-square test, Spearman rank correlation). Results: Among 204 participants, 51% were male, 77% were literate, mean ± S.D. age was 60±12. About 72% experienced headache and 88% said that headache is related to HTN. Behavioural factors and psychological factors were regarded as the leading cause of HTN. Almost 63% participants believed HTN as highly threatening illness. Higher scores in timeline (acute/chronic), personal control, and treatment control revealed that patients believed HTN as a chronic disease with a higher rate of personal and treatment control. Regarding treatment adherence, the mean score was 16.58 (SD = 2.08), and only 14.7% had perfect adherence. Participants were more adherent to medication and appointment keeping rather than reduce salt intake. Duration of HTN diagnosis (p=0.027) and duration under HTN medication (p= 0.021) were found to be significantly associated with treatment adherence. There was a significant positive correlation between illness perception and treatment adherence (ρ = 0.282, p<0.01). Conclusion: Illness perception and treatment adherence are correlated. Hence, it is beneficial to improve illness perception to achieve perfect treatment adherence. Reinforcement is essential to maintain adherence to both medications and behaviour therapy.

In addition to the hepatic metabolism, the role of intestinal microbiota in drug metabolism has been considered important in the biotransformation of xenobiotics. Crocin and its aglycone, crocetin, isolated from many plants, including the dried stigma of Crocus sativus and the fruit of Gardenia jasminoides, have been used in treatment of inflammation, cancer, and metabolic disorders. In this study, the effect of intestinal microbiota on the pharmacokinetics of crocin was studied following single oral treatment with 600 mg/kg crocin to male rats pre-treated with a mixture of antibiotics, such as cefadroxil, oxytetracycline, and erythromycin, for three consecutive days. Following crocin treatment, blood, urine, and feces were collected at various time points for evaluating pharmacokinetic characteristics of crocin and crocetin by using LC-MS. Results showed that intestinal absorption of crocin was relatively marginal when compared with that of crocetin, and that crocin metabolism to crocetin by intestinal microbiota would be a critical step for absorption. The present results clearly suggested that the in vivo pharmacological effects of crocin might be considered as the effects by its aglycone, crocetin, mainly, and that the metabolism of glycosidic natural products by intestinal microbiota should be considered to understand their pharmacodynamic actions.

Introduction Hypertension is a public health challenge and major risk factor for cardiovascular disease in the developing as well as developed countries. The successful management of hypertension depends upon patient’s knowledge on hypertension and self-care practices. MethodsA descriptive cross-sectional study was conducted to identify the knowledge and self-care practice on hypertension among 212 hypertensive patients attending in outpatient department of Manmohan Cardiothoracic Vascular and Transplant Center (MCVTC). Non-probability purposive sampling technique was used. Data was collected through face-to-face interview by using structured questionnaire. Data was analyzed using SPSS version 16.0. ResultsThis study showed that 57.5% of the respondents had adequate level of knowledge on hypertension and 57.1% of the respondents had good overall self-care practice. Regarding self-care practice, we found 100% medicine adherence, 85.8% respondents avoided alcohol and 84.9% avoided smoking, 50.9% followed weight management practice, 48.6% followed dietary management and 44.8% performed physical activity. Level of knowledge was significantly associated with age, gender, educational status and occupation. Self-care practice was only significantly associated with educational status. Level of knowledge and self-care practice were significantly positively correlated. ConclusionMore than half of the respondents had adequate level of knowledge. Regarding self-care practice, nearly sixty percent of the respondents had good self-care practice. To bring those rates to higher level, awareness programs should be launched about diseases and self-care practice on hypertension.

Rutaecarpine, an alkaloid originally isolated from Evodia rutaecarpa, has been used for the treatment of gastrointestinal disorders in Asia. In the present study, the phase I and phase II metabolites of rutaecarpine were investigated in freshly isolated hepatocytes from male Sprague-Dawley rats. The individual metabolites were characterized via liquid chromatography-tandem mass spectrometry. The incubation of rutaecarpine with freshly isolated hepatocytes for 2 h yielded five major phase I metabolites. In addition, three glucuronide conjugates and four sulfate conjugates were observed. Because the majority of metabolites observed in vivo were identified, freshly isolated hepatocytes might be useful for the identification of certain metabolites formed from drug candidates from a reduced number of experimental animals.