Three-dimensional aspects of formulation excipients in drug discovery:a critical assessment on orphan excipients,matrix effects and drug interactions

Formulation/pharmaceutical excipients play a major role in formulating drug candidates,with the objectives of ease of administration,targeted delivery and complete availability.Many excipients used in pharmaceutical formulations are orphanized in preclinical drug discovery.These orphan excipients could enhance formulatability of highly lipophilic compounds.Additionally,they are safe in preclinical species when used below the LD50 values.However,when the excipients are used in formulating compounds with diverse physico-chemical properties,they pose challenges by modulating study results through their bioanalytical matrix effects.Excipients invariably present in study samples and not in the calibration curve standards cause over-/under-estimation of exposures.Thus,the mechanism by which excipients cause matrix effects and strategies to nullify these effects needs to be revisited.Furthermore,formulation excipients cause drug interactions by moderating the pathways of drug metabolizing enzymes and drug transport proteins.Although it is not possible to get rid of excipient driven interactions,it is always advised to be aware of these interactions and apply the knowledge to draw meaningful conclusions from study results.In this review,we will comprehensively discuss a)orphan excipients that have wider applications in preclinical formulations,b)bioanalytical matrix effects and possible approaches to mitigating these effects,and c)excipient driven drug interactions and strategies to alleviate the impacts of drug interactions.

Major bleeding events in octagenarians associated with drug interactions between dabigatran and P-gp inhibitors

Background The direct oral anticoagulant dabigatran does not require any routine therapeutic drug monitoring.Yet,concerns about possible drug interactions susceptible to increase its inherent bleeding risk,especially in very elderly patients,have been raised recently.The aim of our study was to evaluate to what extent the co-prescription of P-gp inhibitors with dabigatran may increase its plasma levels and lead to bleeding complications,in usual conditions of care of the very elderly.Methods Fifty-eight patients over 85 years old with non valvular atrial fibrillation receiving dabigatran were included in a prospective cohort.Prescriptions were screened for the presence of P-gp inhibitors(Group A)or not(Group B).Results Patients from Group A had increased dabigatran mean plasma concentrations as compared with patients from Group B(A vs.B:182.2±147.3 vs.93.7±64.9 ng/m L).One third of the patients from Group A had dabigatran concentrations that were deemed"out of range"versus none in Group B(P=0.05).This was associated with more frequent bleeding complications in Group A(A:30.4%,B:8.6%,P=0.04).Conclusion In our cohort of very elderly patients,at least,the co-prescription of dabigatran with P-gp inhibitors in usual conditions of care resulted in higher dabigatran plasma concentrations and more frequent bleeding occurrences.

Measuring drug similarity using drug–drug interactions

Combination therapy is a promising approach to address the challenge of antimicrobial resistance,and computational models have been proposed for predicting drug–drug interactions.Most existing models rely on drug similarity measures based on characteristics such as chemical structure and the mechanism of action.In this study,we focus on the network structure itself and propose a drug similarity measure based on drug–drug interaction networks.We explore the potential applications of this measure by combining it with unsupervised learning and semi-supervised learning approaches.In unsupervised learning,drugs can be grouped based on their interactions,leading to almost monochromatic group–group interactions.In addition,drugs within the same group tend to have similar mechanisms of action(MoA).In semi-supervised learning,the similarity measure can be utilized to construct affinity matrices,enabling the prediction of unknown drug–drug interactions.Our method exceeds existing approaches in terms of performance.Overall,our experiments demonstrate the effectiveness and practicability of the proposed similarity measure.On the one hand,when combined with clustering algorithms,it can be used for functional annotation of compounds with unknown MoA.On the other hand,when combined with semi-supervised graph learning,it enables the prediction of unknown drug–drug interactions.

HIV/HCV Antiviral Drug Interactions in the Era of Direct-acting Antivirals

Therapy for human immunodeficiency virus (HIV) and chronic hepatitis C has evolved over the past decade,resulting in better control of infection and clinical outcomes;however,drug-drug interactions remain a significant hazard.Joint recommendations from the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America regarding drug-drug interactions between HIV antiretroviral agents and direct-acting antiviral agents for treatment of hepatitis C virus (HCV) infection are reviewed here.This review is oriented to facilitate appropriate selection of an antiviral therapy regimen for HCV infection based on the choice of antiretroviral therapy being administered and,if necessary,switching antiretroviral regimens.

Review of Clinically Relevant Drug Interactions with Next Generation Hepatitis C Direct-acting Antiviral Agents

In this review,we examine the pharmacokinetics and clinically relevant drug interactions of the newer generation direct-acting antivirals(DAAs)for the treatment of chronic hepatitis C,specifically sofosbuvir/velpatasvir(Epclusa®),sofosbuvir/velpatasvir/voxilaprevir(Vosevi®),glecaprevir/pibrentasvir(Maviret®),and elbasvir/grazoprevir(Zepatier®).We searched MEDLINE(1948-January 2020),Embase(1964-January 2020),Google,and GoogleScholar using the terms pharmacokinetics,drug interaction,drug metabolism,sofosbuvir,velpatasvir,Epclusa,voxilaprevir,Vosevi,glecaprevir,pibrentasvir,Maviret,elbasvir,grazoprevir,and Zepatier,from inception to January 13,2020.The search was limited to randomized controlled trials,in vitro studies,prospective and retrospective human studies,drug monographs,abstracts,and conference proceedings.All relevant published literature on pharmacokinetic and pharmacodynamic interactions involving DAAs were reviewed and the data extracted.Numerous clinically relevant drug-drug interactions(DDIs)were identified with the newer generation DAAs and commonly prescribed drugs.NS3/4A protease inhibitors are more likely to be involved in DDIs,followed by NS5A inhibitors and NS5B polymerase inhibitor.The majority of clinically relevant DDIs are predictable,according to known pharmacokinetic,pharmacodynamics,and physicochemical properties of DAAs;however,in select cases,unpredictable DDIs do occur.As expected,many drug interactions exist between newer generation DAAs and commonly prescribed medications.While the majority of clinically relevant interactions are predictable,many require therapeutic dose adjustment or careful selection of non-interacting drugs.In select cases,severe and unpredictable drug interactions can occur.Clinicians should consult hepatitis C virus pharmacotherapy experts and tertiary drug interaction resources when initiating DAA therapy in patients taking other medications.

P-glycoprotein mediated interactions between Chinese materia medica and pharmaceutical drugs

P-glycoprotein(P-gp)is an important transmembrane ATP-binding cassette(ABC)drug efflux transporter expressed in various human tissues such as the intestines,liver,kidneys,and bloodbrain barrier.It limits the intracellular concentration of xenobiotics by pumping them out of the cells,affecting drug pharmacokinetics and therapeutic effects.With its broad substrate specificity,it has the potential to remove a wide range of drugs from Chinese materia medica(CMM),including conventional medicines and active compounds.Increasing evidence has confirmed the superior therapeutic effectiveness of CMM in treating a wide range of diseases worldwide,as well as in conjunction with western drugs.As a result,herbal medicine-drug compounds have prompted widespread concern,with the majority of these interactions involving transporters such as P-gp.This review systematically summarizes the inhibition or induction of P-gp expression/function by active CMM compounds and the underlying regulatory mechanisms.It will aid in improving understanding of the synergistic or inhibiting effects associated with transporter P-gp as well as rational safety concerns for using CMM,particularly in combination with drugs.

Activation of PXR causes drug interactions with Paxlovid in transgenic mice

Paxlovid is a nirmatrelvir(NMV)and ritonavir(RTV)co-packaged medication used for the treatment of coronavirus disease 2019(COVID-19).The active component of Paxlovid is NMV and RTV is a pharmacokinetic booster.Our work aimed to investigate the drug/herb-drug interactions associated with Paxlovid and provide mechanism-based guidance for the clinical use of Paxlovid.By using recombinant human cytochrome P450s(CYPs),we confirmed that CYP3A4 and 3A5 are the major enzymes responsible for NMV metabolism.The role of CYP3A in Paxlovid metabolism were further verified in Cyp3a-null mice,which showed that the deficiency of CYP3A significantly suppressed the metabolism of NMV and RTV.Pregnane X receptor(PXR)is a ligand-dependent transcription factor that upregulates CYP3A4/5 expression.We next explored the impact of drug-and herb-mediated PXR activation on Paxlovid metabolism in a transgenic mouse model expressing human PXR and CYP3A4/5.We found that PXR activation increased CYP3A4/5 expression,accelerated NMV metabolism,and reduced the systemic exposure of NMV.In summary,our work demonstrated that PXR activation can cause drug interactions with Paxlovid,suggesting that PXR-activating drugs and herbs should be used cautiously in COVID-19 patients receiving Paxlovid.

Assessment of the potential interactions between favipiravir and radiocontrast agents

BACKGROUND In cases of coronavirus disease 2019(COVID-19),favipiravir is commonly included to the therapy regimen.Drug interactions between favipiravir and other COVID-19 therapy drugs are frequently researched.However,no research on possible drug interactions between Favipiravir and radiocontrast agents,which have become almost crucial in diagnostic processes while not being part of the treatment,has been found.AIM To determine potential medication interactions between Favipiravir and radiocontrast agents.METHODS The study comprised patients who were taking Favipiravir for COVID-19 therapy and underwent a contrast-enhanced computed tomography(CT)or magnetic resonance imaging(MRI)test while taking the medicine.The computerized patient files of the cases included in the study,as well as the pharmacovigilance forms in the designated hospital,were evaluated for this purpose.RESULTS The study included the evaluation of data from 1046 patients.The study sample's mean age was 47.23±9.48 years.The mean age of cases with drug interactions was statistically significant greater than that of cases with no drug interactions(P=0.003).When evaluated with logistic regression analysis,a 1-year raises in age increases the risk of developing drug interactions by 1.63 times(P=0.023).There was no statistically significant difference in the occurrence of medication interactions between the sexes(P=0.090).Possible medication interactions were discovered in 42 cases(4%).CONCLUSION The findings of this study revealed that the most notable findings as a result of the combined use of contrast agents and favipiravir were increased creatinine and transaminase values,as well as an increase in the frequency of nausea and vomiting.The majority of drug interactions discovered were modest enough that they were not reflected in the clinic.Drug interactions become more common as people get older.

Rational prescription of drugs within similar therapeutic or structural class for gastrointestinal disease treatment: Drug metabolism and its related interactions

AIM:To review and summarize drug metabolism and its related interactions in prescribing drugs within the similar therapeutic or structural class for gastrointestinal disease treatment so as to promote rational use of medicines in clinical practice.METHODS:Relevant literature was identified by performing MEDLINE/Pubmed searches covering the period from 1988 to 2006.RESULTS:Seven classes of drugs were chosen,including gastric proton pump inhibitors,histamine H2-receptor antagonists,benzamide-type gastroprokinetic agents,selective 5-HT3 receptor antagonists,fluoroquinolones,macrolide antibiotics and azole antifungals.They showed significant differences in metabolic profile(i.e.,the fraction of drug metabolized by cytochrome P450(CYP),CYP reaction phenotype,impact of CYP genotype on interindividual pharmacokinetics variability and CYP-mediated drug-drug interaction potential).Many events of severe adverse drug reactions and treatment failures were closely related to the ignorance of the above issues.CONCLUSION:Clinicians should acquaint themselves with what kind of drug has less interpatient variability in clearance and whether to perform CYP genotyping prior to initiation of therapy.The relevant CYP knowledgehelps clinicians to enhance the management of patients with gastrointestinal disease who may require treatment with polytherapeutic regimens.

Development of Extraction and Detection Method for a Chemotherapeutic Drug with Phenytoin in Biological Samples

Dexamethasone is classified as a corticosteroid and is commonly used among cancer patients to decrease the amount of swelling around the tumor. Among patients with cancer, in particular brain tumors, seizures can become a daily routine in their everyday lives. To counteract the seizures, an antiepileptic drug such as phenytoin is administered to act as an anticonvulsant. Phenytoin and dexamethasone are frequently administrated concurrently to brain cancer patients. A previous study has shown that phenytoin serum concentration decreases when administrated concurrently with dexamethasone. Thus, it is important to monitor the concentration of these two drugs in biological samples to ensure that the proper dosages are administrated to the patients. This study aims to develop an effective extraction and detection method for dexamethasone and phenytoin. A reverse-phase high-performance liquid chromatography (HPLC) method with UV/Vis detection has been developed to separate phenytoin and dexamethasone at 219 nm and 241 nm respectively from urine samples. The mobile phase consists of a mixture of 0.01 M KH2PO4, acetonitrile, and methanol adjusted to pH 5.6 (48:32:20) and is pumped at a flow rate of 1.0 mL/min. Calibration curves were prepared for phenytoin and dexamethasone (r2 > 0.99). An efficient solid-phase extraction (SPE) method for the extraction of dexamethasone and phenytoin from urine samples was developed with the use of C-18 cartridges. The percent recovery for phenytoin and dexamethasone is 95.4% (RSD = 1.15%) and 81.1% (RSD = 3.56%) respectively.

Drug utilization of clarithromycin for gastrointestinal disease treatment

AIM： To evaluate the patterns of use of clarithromycin for gastrointestinal disease treatment and promote its rational use.METHODS： Using a structured pro forma, we conducted a two-month survey of the electronic prescriptions containing immediate-release （IR） or sustained-release （SR） product of clarithromycin for outpatients with gastrointestinal diseases in a 2200-bed general hospital. Suitability of the prescription was audited retrospectively. RESULTS： One hundred and sixty-four prescriptions of SR product and 110 prescriptions of IR product were prescribed for gastrointestinal disease treatment. Among prescriptions for anti-Helicobacter pylori （H pylori） therapy, triple therapy take the dominant position （91.8%）, followed by quadruple therapy （4.3%） and dual therapy （3.9%）. Amoxicillin was the most frequently co-prescribed antibiotic.Furazolidone and levofloxacin are used more widely than metronidazole or tinidazole. Clarithromycin SR was administered at inappropriate time points in all prescriptions. Fifty percent of all prescriptions of clarithromycin SR, and 6.4% of prescriptions of clarithromycin IR, were prescribed at inappropriate dosing intervals. Surprisingly, disconcordance between diagnoses and indications was observed in all prescriptions of clarithromycin SR which has not been approved for treating Hpy/ori infection although off-label use for this purpose was reported in literature. On the contrary, only one prescription （0.9%） of clarithromycin IR was prescribed for unapproved indication （i.e. gastro-oesophageal reflux disease）. 1.4% of prescriptions for chronic gastritis or peptic ulcer treatment were irrational in that clarithromycin was not co-prescribed with gastric acid inhibitors. Clinical significant CYP3A based drug interactions with clarithromycin were identified. CONCLUSION： There is a great scope to improve the quality of clarithromycin prescribing in patients with gastrointestinal disease, especially with regard to administration schedule, concordance between indications and diagnoses and management of drug interactions.

Relative efficacy of some prokinetic drugs in morphine-induced gastrointestinal transit delay in mice

AIM:To study the relative efficacy of cisapride, metoclopramide,domperidone,erythromycin and mosapride on gastric emptying(GE)and small intestinal transit(SIT) in morphine treated mice. METHODS:Phenol red marker meal was employed to estimate GE and SIT in Swiss albino mice of either sex.The groups included were control,morphine 1 mg/kg(s.c.15 rain before test meal)alone or with(45 rain before test meal p.o.)cisapride 10 mg/kg,metoclopramide 20 mg/kg, domperidone 20 mg/kg,erythromycin 6 mg/kg and mosapride 20 mg/kg. RESULTS:Cisapride,metoclopramide and mosapride were effective in enhancing gastric emptying significantly(P<0.001) whereas other prokinetic agents failed to do so in normal mice.Metoclopramide completely reversed morphine induced delay in gastric emptying followed by mosapride. Metoclopramide alone was effective when given to normal mice in increasing the SIT.Cisapride,though it did not show any significant effect on SIT in normal mice,was able to reverse morphine induced delay in SIT significantly(P<0.001) followed by metoclopramide and mosapride. CONCLUSION:Metoclopramide and cisapride are most effective in reversing morphine-induced delay in gastric emptying and small intestinal transit in mice respectively.

Drug–Target Interaction Prediction Model Using Optimal Recurrent Neural Network

Drug-target interactions prediction(DTIP)remains an important requirement in thefield of drug discovery and human medicine.The identification of interaction among the drug compound and target protein plays an essential pro-cess in the drug discovery process.It is a lengthier and complex process for pre-dicting the drug target interaction(DTI)utilizing experimental approaches.To resolve these issues,computational intelligence based DTIP techniques were developed to offer an efficient predictive model with low cost.The recently devel-oped deep learning(DL)models can be employed for the design of effective pre-dictive approaches for DTIP.With this motivation,this paper presents a new drug target interaction prediction using optimal recurrent neural network(DTIP-ORNN)technique.The goal of the DTIP-ORNN technique is to predict the DTIs in a semi-supervised way,i.e.,inclusion of both labelled and unlabelled instances.Initially,the DTIP-ORNN technique performs data preparation process and also includes class labelling process,where the target interactions from the database are used to determine thefinal label of the unlabelled instances.Besides,drug-to-drug(D-D)and target-to-target(T-T)interactions are used for the weight initia-tion of the RNN based bidirectional long short term memory(BiLSTM)model which is then utilized to the prediction of DTIs.Since hyperparameters signifi-cantly affect the prediction performance of the BiLSTM technique,the Adam optimizer is used which mainly helps to improve the DTI prediction outcomes.In order to ensure the enhanced predictive outcomes of the DTIP-ORNN techni-que,a series of simulations are implemented on four benchmark datasets.The comparative result analysis shows the promising performance of the DTIP-ORNN method on the recent approaches.

COVID-19 infection in a kidney transplant recipient—special emphasis on pharmacokinetic interactions:A case report

BACKGROUND Solid organ transplant recipients are considered to be at high-risk of developing coronavirus disease 2019(COVID-19)-related complications.The optimal treatment for this patient group is unknown.Consequently,the treatment of COVID-19 in kidney transplant recipients should be determined individually,considering patient age and comorbidities,as well as graft function,time of transplant,and immunosuppressive treatment.Immunosuppressive treatments may give rise to severe COVID-19.On the contrary,they may also lead to a milder and atypical presentation by diminishing the immune system overdrive.CASE SUMMARY A 50-year old female kidney transplant recipient presented to the transplant clinic with a progressive dry cough and fever that started three days ago.Although the COVID-19 test was found to be negative,chest computed tomography images showed consolidation typical of the disease;thus,following hospital admission,anti-bacterial and COVID-19 treatments were initiated.However,despite clinical improvement of the lung consolidation,her creatinine levels continued to increase.Ultrasound of the graft showed no pathology.The tacrolimus blood level was determined and the elevation in creatinine was found to be related to an interaction between tacrolimus and azithromycin.CONCLUSION During the COVID-19 pandemic,various single or combination drugs have been utilized to find an effective treatment regimen.This has increased the possibility of drug interactions.A limited number of studies published in the literature have highlighted some of these pharmacokinetic interactions.Treatments used for COVID-19 therapy;azithromycin,atazanavir,lopinavir/ritonavir,remdesivir,favipiravir,chloroquine,hydroxychloroquine,nitazoxanide,ribavirin,and tocilizumab,interact with immunosuppressive treatments,most importantly with calcineurin inhibitors.Thus,their levels should be frequently monitored to prevent toxicity.

Impact of Drug-Drug Interaction between CDK4/6 Inhibitors and Proton Pump Inhibitors on Survival Outcomes in the Treatment of Metastatic Breast Cancer—Real World Data from a Portuguese Center

Introduction: Proton pump inhibitors (PPi) are widely prescribed, including in patients undergoing treatment for advanced breast cancer (ABC). Due to the pharmacokinetic characteristics of the CDK4/6 inhibitor (Ci) palbociclib a drug interaction with PPi was hypothesized. It was shown in a retrospective study that this association was an independent predictive factor for worse progression-free survival (PFS). Objective: To verify the impact of concomitant administration of PPi with Ci on overall survival (OS) and PFS. Material and Methods: This is a retrospective cohort study of patients treated with Ci for HR+HER2-ABC in the period from Feb/2017 to Aug/2020. SPSS software was used for data processing. Univariate analysis was done by the Kaplan-Meier method and log-rank test, and multivariate analysis by COX regression. P-value < 0.05 was considered significant. Results: 80 patients were included. The median age at diagnosis of ABC was 56 years (25 - 75). Treatment with Ci was 1st line for ABC in 68.8%. Choice of Ci was palbociclib in 73.8% (n = 59) and ribociclib in 26.3% (n = 21). The hormone partner was a nonsteroidal aromatase inhibitor in 45.0%, and fulvestrant in 55.0% of cases. 37.5% of patients were on PPi, and 70.0% of them were during the entire treatment (23.3% omeprazole, 73.4% pantoprazole, 3.3% others). Patients taking concomitant PPi and Ci had lower OS (OS-3 years 42.6% vs. 63.4%, p = 0.254) and PFS (PFS med 15 m. vs. 21 m., p = 0.733), although with no statistically significant difference. Discussion: In the sample, there was a numerical difference, without the statistical significance in the use of PPi in the survival of patients under Ci. This difference could be more evident with a longer follow-up and a larger sample size. This study intends to alert to the growing importance of checking for drug interactions. Polymedication, advanced age and the presence of several comorbidities are real problems in patients with ABC. Conclusion: Real-world data from this center demonstrate a negative, non-statistically significant impact of PPi treatment on survival outcomes, in patients treated with Ci for HR+HER2-ABC.

Effects of progesterone on gastric emptying and intestinal transit in male rats

AIM: To study the dose-dependent of progesterone (P) effect and the interaction between the oxytocin (OT) and P on gastrointestinal motility. METHODS: In order to monitor the gastric emptying and intestinal transit, the SD male rats were intubated via a catheter with normal saline (3 ml/kg) containing Na(2)(51)CrO(4) (0.5 microCi/ml) and 10% charcoal. OT was dissolved into normal saline and P was dissolved into 75% alcohol. RESULTS: Low does of P (1 mg/kg, i.p.) enhanced the gastric emptying (75+/-3%, P【0.05) and high dose of P (5 mg/kg, i.p.) inhibit it (42+/-11.2%, P【0.01). P (1 mg/kg) increased the intestinal transit (4.2+/-0.3, P【0.05) while the higher dose (10-20 mg/kg) had no effect. OT (0.8 mg/kg, i.p.) inhibited the gastric emptying (23.5+/-9.8%, P【0.01). The inhibitory effects of P(20 mg/kg) (32+/-9.7%, P【0.05) and OT (0.8 mg/kg) on gastric emptying enhanced each other when the two chemicals were administrated simultaneously (17+/-9.4%, P【0.01). CONCLUSION: Low dose of P increased GI motility while high dose of P decreased it. During the later period of pregnancy, elevated plasma level of OT may also participate in the gastrointestinal inhibition.

Diet in neurogenic bowel management:A viewpoint on spinal cord injury

The aim of this review is to offer dietary advice for individuals with spinal cord injury(SCI)and neurogenic bowel dysfunction.With this in mind,we consider health conditions that are dependent on the level of lesion including skeletal muscle atrophy,autonomic dysreflexia and neurogenic bladder.In addition,SCI is often associated with a sedentary lifestyle,which increases risk for osteoporosis and diseases associated with chronic low-grade inflammation,including cardiovascular and chronic kidney diseases.The Mediterranean diet,along with exercise and dietary supplements,has been suggested as an anti-inflammatory intervention in individuals with SCI.However,individuals with chronic SCI have a daily intake of whole fruit,vegetables and whole grains lower than the recommended dietary allowance for the general population.Some studies have reported an increase in neurogenic bowel dysfunction symptoms after high fiber intake;therefore,this finding could explain the low consumption of plant foods.Low consumption of fibre induces dysbiosis,which is associated with bothendotoxemia and inflammation.Dysbiosis can be reduced by exercise and diet in individuals with SCI.Therefore,to summarize our viewpoint,we developed a Mediterranean diet-based diet and exercise pyramid to integrate nutritional recommendations and exercise guidelines.Nutritional guidelines come from previously suggested recommendations for military veterans with disabilities and individuals with SCI,chronic kidney diseases,chronic pain and irritable bowel syndrome.We also considered the recent exercise guidelines and position stands for adults with SCI to improve muscle strength,flexibility and cardiorespiratory fitness and to obtain cardiometabolic benefits.Finally,dietary advice for Paralympic athletes is suggested.

Impact of cigarette smoking on response to interferon therapy in chronic hepatitis C Egyptian patients

AIM:Smoking may affect adversely the response rate to interferon-α.Our objective was to verify this issue among chronic hepatitis C patients. METHODS:Over the year 1998,138 chronic hepatitis C male Egyptian patients presenting to Cairo Liver Center, were divided on the basis of smoking habit into:group I which comprised 38 smoker patients(>30 cigarettes/d) and group Ⅱ which included 84 non-smoker patients. Irregular and mild smokers(16 patients)were excluded. Non eligible patients for interferon-α therapy were excluded from the study and comprised 3/38(normal ALT)in group I and 22/84 in group Ⅱ(normal ALT,advanced cirrhosis and thrombocytopenia).Group I was randomly allocated into 2 sub-groups:group Ia comprised 18 patients who were subjected to therapeutic phlebotomy while sub-group Ib consisted of 17 patients who had no phlebotomy.In sub-group la,3 patients with normal ALT after repeated phlebotomies were excluded from the study.Interferon-α 2b 3 MU/TIW was given for 6 mo to 15 patients in group Ia,17 patients in group Ib and 62 patients in group Ⅱ. Biochemical,virological end-of-treatment and sustained responses were evaluated. RESULTS:At the end of interferon-α treatment,ALT was normalized in 3/15 patients(20%)in group Ia and 2/17 patients(11.8%)in group Ib compared to17/62 patients (27.4%)in group Ⅱ(P=0.1).Whereas 2/15 patients(13.3%) in group Ia.and 2/17 patients(11.8%)in group Ib lost viraemia compared to 13/62 patients(26%)in group Ⅱ (P=0.3).Six months later,ALT was persistently normal in 2/15 patients(13.3%)in group 1a and 1/17 patients (5.9%)in group Ib compared to 9/62 patients(14.5%)in group Ⅱ(P=0.47).Viraemia was eliminated in 1/15 patients (6.7%)in group Ia and 1/17 patients(5.9%)in group Ib compared to 7/62 patients(11.3%) in group Ⅱ,but the results did not mount to statistical significance(P=0.4). CONCLUSION:Smokers suffering from chronic hepatitis C tend to have a lower response rate to interferon-α compared to non-smokers.Therapeutic phlebotomy improves the response rate to interferon-α therapy among this group.

Inhibitory effect and mechanism of acarbose combined with gymnemic acid on maltose absorption in rat intestine

AIM: To compare the combinative and individual effect of acarbose and gymnemic acid (GA) on maltose absorption and hydrolysis in small intestine to determine whether nutrient control in diabetic care can be improved by combination of them. METHODS: The absorption and hydrolysis of maltose were studied by cyclic perfusion of intestinal loops in situ and motility of the intestine was recorded with the intestinal ring in vitro using Wistar rats. RESULTS: The total inhibitory rate of maltose absorption was improved by the combination of GA (0.1g/L-1.0 g/L) and acarbose (0.1 mmol/L-2.0 mmol/L) throughout their effective duration (P 【0.05, U test of Mann-Whitney), although the improvement only could be seen at a low dosage during the first hour. With the combination, inhibitory duration of acarbose on maltose absorption was prolonged to 3h and the inhibitory effect onset of GA was fastened to 15 min. GA suppressed the intestinal mobility with a good correlation (r = 0.98) to the inhibitory effect of GA on maltose absorption and the inhibitory effect of 2 mmol/L (high dose) acarbose on maltose hydrolysis was dual modulated by 1g/L GA in vivo indicating that the combined effects involved the functional alteration of intestinal barriers. CONCLUSION: There are augmented effects of acarbose and GA,which involve pre-cellular and paracellular barriers. Diabetic care can be improved by employing the combination.

Self-medication with nutritional supplements and herbal over-the-counter products

In recent years,the popularity increased for nutritional supplements and herbal products.Prescription drugs,but not herbal therapies are paid by health insurances.They are sold over-the-counter(OTC)on the patients’own expense.However,there are potential risks of self-medication,e.g.incorrect self-diagnosis,severe adverse reactions,dangerous drug interactions,risk of addiction etc.They are often used by patients at their own discretion without knowledge of and control by their physicians.Certain users are at risk of intoxication.Multiple medications taken by older patients increase the risk for adverse drug reactions,drug-drug interactions,and compliance problems for this age group(polypharmacy).Herbals should be discontinued prior to operations to avoid interactions with anesthetics or anticoagulants.Herbal preparations may also be carcinogenic or interfere with cancer treatments.Pregnant women use various OTC preparations.However,in many cases,it is unclear whether their use is safe for mother or baby.Self-medication with herbals is also largely distributed among anxious and depressive patients,and patients with other conditions and symptoms.The popularity of herbal products has also brought concerns on quality,efficacy and safety.Cases of botanical misidentification,contaminations with heavy metals,pesticides,radioactivity,organic solvents,microbials as well as adulteration with chemical drugs necessitate the establishment of international quality control standards.Hepatotoxic effects have been reported for more than 300 plant species,and some commonly used herbs have been demonstrated to interact with Western medication.Health care professionals have a critical responsibility assessing the self-care ability of their patients.Databases are available for pharmacists with information on action,side effects and toxicities as well as herbdrug interactions.There is a need for established guidelines regarding the correct use of nutritional supplements and herbal OTC preparations(phytovigilance).Physicians,pharmacists,and other health care professionals have to counsel patients and the general public on the benefits and risks associated with herbal drugs.Information centers for consumers and general practitioners are needed,and convincing evidence on safety and efficacy of herbal products has to be demonstrated in placebo-controlled,double blind and randomized clinical trials.