Blood pressure in the Congolese adult population of South Kivu, Democratic Republic of Congo: Preliminary results from the Bukavu Observ Cohort Study

BACKGROUND

Providing factual data about non-communicable diseases (NCDs) is of utmost importance in the sub-Saharan African countries where NCDs and arterial hypertension data remain scattered, scarce, and less representative given the region's heterogeneous population. Within this context, the interuniversity cooperation VLIR-UOS/Catholic University of Bukavu (Democratic Republic of Congo) has established an integrated project for monitoring hypertension and cardiovascular risk factors in the population of South Kivu. The aim of the study was to present the basic results of the determinants of blood pressure in the cohort studied.

METHODS

In 2013 and 2014, trained interviewers collected the anthropometric parameters, blood pressure, and medical history of 7405 adults (3060 in urban areas and 4345 in rural areas) including 3162 males and 4243 females; the cohort is expected to be followed for 9 years.

RESULTS

The average age of the entire group was 33.0±16.7 years. Compared to men, women had significantly higher obesity indices (P<0.0001), lower blood pressure between 20 and 39 years of age (P<0.0001) but higher blood pressure at 60 years of age and older (P<0.0001). Blood pressure was positively correlated with body mass index, waist circumference, and paradoxically with consumption of vegetables, but negatively correlated with the consumption of fruit, intense physical activity, and relaxation at home.

CONCLUSIONS

These results show that a cohort study is feasible in the Democratic Republic of Congo. The factual data analysis can contribute to health policy orientation and setting up of preventive measures. Since most correlated risk factors are preventable, recommendations can already be made in the fight against high blood pressure in this population.

[Effectiveness of pharmaceutical care for patients with COPD: translated review of the recently published PHARMACOP trial]

BACKGROUND AND AIM

Few well-designed randomized controlled trials (RCT) regarding the impact of community pharmacist interventions on pharmacotherapeutic monitoring of patients with Chronic Obstructive Pulmonary Disease [COPD) have been conducted. We assessed the effectiveness of a pharmaceutical care program for patients with COPD.

METHODS

The PHARMACOP-trial was a single-blind 3-month RCT, conducted in 170 community pharmacies in Belgium, enrolling patients prescribed daily COPD medication, aged > or = 50 years, and with a smoking history > or = 10 pack-years. A computer-generated randomization sequence allocated patients to intervention (n = 371), receiving protocol-defined pharmacist care, or control group (n = 363), receiving usual pharmacist care 11:1 ratio, stratified by center). Interventions, focusing on inhalation technique and adherence to maintenance therapy, were carried out at start of the trial and at one month follow-up. Primary outcomes were inhalation technique and medication adherence. Secondary outcomes were exacerbation rate, dyspnea, COPD specific and generic health status and smoking behavior.

RESULTS

From December 2010 to April 2011, 734 patients were enrolled. 42 patients (5.7%) were lost to follow-up. At the end of the trial, inhalation score (Mean estimated difference [delta], 13.5%; 95% Confidence Interval [CI], 10.8-16.1; P < .0001] and medication adherence [(delta, 8.51%; 95% CI, 4.63-12.4; P < .0001) were significantly higher in the intervention group compared to the control group. In the intervention group, a significantly lower hospitalization rate was observed (9 vs 35 hospitalizations; Rate Ratio, 0.28; 95% CI, 0.12-0.64; P = .003). No other significant between-group differences were observed.

CONCLUSION

The PHARMACOP-trial demonstrates that pragmatic pharmacist care programs improve both inhalation technique and medication adherence in patients with COPD and could reduce hospitalization rates. The protocolled intervention used in this trial was specifically designed for and evaluated in (Belgian) community pharmacies. This may facilitate future implementation in the Belgian context.

Sunitinib for metastatic renal cell cancer patients: observational study highlighting the risk of important drug-drug interactions

WHAT IS KNOWN AND OBJECTIVE

Sunitinib, a CYP3A4 substrate, is standard of care treatment in metastatic renal cell carcinoma (mRCC) and is administered orally as a single dose of 50 mg, in a 4 weeks on/2 weeks off regimen. Frequently, dose reduction is necessary because of toxicity, as is the association of comedication to treat side effects. In addition, existing comorbidities in these patients necessitate the intake of various classes of chronic medication. Only limited data are available on the risk of drug-drug interactions (DDI). The objective of our paper was to evaluate prescribed dose, comedication, risk of drug-drug interactions and outcome among patients with mRCC treated with sunitinib.

METHODS

A single-centre, retrospective analysis was performed for patients with mRCC treated with sunitinib. The drug interaction databases 'Clinical Pharmacology' and 'Lexicomp' were used to screen for possible interactions.

RESULTS AND DISCUSSION

The hospital files of 36 patients with mRCC were evaluated. Twenty-two patients received sunitinib as first-line treatment. Progression-free survival (PFS) in this first-line group was longer for patients that started with full-dose sunitinib (21·1 months; n = 12) than for patients started on reduced dose (3·5 months; n = 10). In the whole group of 36 patients, an average of 6·8 comedications was taken. Possible pharmacodynamic drug-drug interactions were most frequently found (47%) and reported as major interactions (QT prolongation). Risk of pharmacokinetic interactions due to co-administration of CYP inhibitors, CYP inducers, CYP substrates and PgP substrates was reported for 8%, 11%, 53% and 19%, respectively. These interactions were reported as major or moderate.

WHAT IS NEW AND CONCLUSION

Patients with mRCC under treatment with sunitinib at a reduced starting dose had a decreased PFS compared with patients started with full-dose sunitinib. Due to adverse drug reactions and comorbidity, patients under sunitinib, a CYP3A4 substrate, took an average of 6·8 comedications provoking an important risk of major-to-moderate drug-drug interactions. With the help of a multidisciplinary team, avoidance of drug-drug interactions could be obtained. Moreover, serial ECG monitoring is recommended for patients at high risk of QT prolongation.

The effects of abrupt antipsychotic discontinuation in cognitively impaired older persons: a pilot study

BACKGROUND

Antipsychotic use for behavioural and psychological symptoms of dementia (BPSD) is controversial. Guidelines advise to reduce antipsychotics given the adverse effects and limited efficacy, to limit dose and treatment duration as well as to undertake discontinuation.

METHODS

A pilot study with 40 hospitalised geriatric cognitively impaired patients, in which the effects of abrupt antipsychotic discontinuation were investigated, using neuropsychiatric inventory (NPI) scores before and one month after discontinuation. Withdrawal symptoms were monitored thrice a day with a checklist during five consecutive days.

RESULTS

Participants (n = 40) had a mean age of 84 years (range 67-95) and 53% were male. The total mean baseline NPI score was 21 (SD 12) with predominantly behavioural rather than psychological disturbances. After abrupt discontinuation, mild withdrawal symptoms were observed in 72% of the patients, with frequencies of symptoms peaking on day 2 (53%) and day 3 (48%). After one month, 31 patients (85%) were still off antipsychotics and improved on the majority of NPI domains, with a total mean NPI score decreasing from 18 (SD 13) to 12 (SD 8, p = 0.003). In the relapse group, there was no deterioration associated with the abrupt discontinuation and subsequent resumption of therapy with a total mean NPI score decreasing from 31 (SD 12) at baseline to 27 (SD 8) at one-month follow-up (p = 0.345).

CONCLUSION

Abrupt antipsychotic discontinuation appears to be feasible in older individuals with BPSD. Systematically performed discontinuation efforts in clinical practice are needed to differentiate between patients where antipsychotics have no added value and patients where the benefits outweigh the risks.

Medication management among home-dwelling older patients with chronic diseases: possible roles for community pharmacists

OBJECTIVE

To describe medication management among home-dwelling older adults. These data should allow us to identify potential problems and to indicate target areas for community pharmacist intervention.

DESIGN

Cross-sectional observational study.

SETTING

Community pharmacies (n=86) in Belgium.

PARTICIPANTS

Home-dwelling older adults using at least one chronic medicine (n=338).

MEASUREMENTS

Data on drug use were taken from the electronic pharmacy databases, while drug adherence was measured by pill count, self-report and estimation by GP and pharmacist. Drug knowledge and practical drug management capacity were assessed by patient interview and questionnaire, respectively.

RESULTS

The study population (n=338) used a median of 5 chronic drugs per patient. Half of our sample (n=169) used psychotropic medication chronically, mainly benzodiazepines. In 100 patients (29.6%) at least one drug-drug interaction of potential clinical significance was observed. The overall mean adherence per patient was very high (98.1%), but 39.6% of individuals was underadherent with at least one medication. Seventy-six % of patients had an acceptable knowledge of the indication for at least 75% of their medication. In nearly 15 % of the study population cognitive impairment was suspected by the mini-cog test. The participants reported several practical problems with drug taking: difficulties with vision (32.0%), blister opening (12.1%), tablet swallowing (14.8%), tablet splitting (29.7% [represents % of patients who have to split tablets]) and distinction between different drug packages (23.4%).

CONCLUSION

This study identified the following aspects of medication management by home-dwelling older adults that could be improved by pharmaceutical care services: (i) assistance of cognitively impaired patients, (ii) management of practical drug taking problems, (iii) DDI screening, (iv) drug adherence, and (v) chronic benzodiazepine use.

[Self-medication of regular headache: a community pharmacy-based survey in Belgium]

AIM

This observational community pharmacy-based study aimed to investigate headache characteristics and medication use of persons with regular headache presenting for self-medication.

METHODS

Participants (n=1205) completed ii) a questionnaire to assess current headache medication and previous physician diagnosis, (ii) the ID Migraine Screener [ID-M] and (iii) the MIDAS questionnaire.

RESULTS

Forty-four % of the study population (n=528) did not have a physician diagnosis of their headache, and 225 of them (225/528, 42.6%) were found to be ID-M positive. The most commonly used acute headache drugs were paracetamol (used by 62% of the study population), NSAIDs (39%) and combination analgesics (36%). Only 12% of patients physician-diagnosed with migraine used prophylactic migraine medication, and 25% used triptans. About 24% of our sample (n=292) chronically overused acute medication, which was combination analgesic overuse (n=166), simple analgesic overuse (n=130), triptan overuse (n=19), ergot overuse (n=6) and opioid overuse (n=51). Only 14.5% was ever advised to limit intake frequency of acute headache treatments.

CONCLUSIONS

This study identified underdiagnosis of migraine, low use of migraine prophylaxis and triptans, and high prevalence of medication overuse among subjects seeking self-medication for regular headache. Community pharmacists have a strategic position in education and referral of these self-medicating headache patients.

Cardiac toxicity of trastuzumab: experience at the Ghent Unversity Hospital, Belgium

INTRODUCTION

Trastuzumab (TRAS) is a humanised monoclonal antibody that is targeted against the HER2 growth factor receptor. Over-expression of the receptor occurs in around 15-25% of women with early breast cancer (CA). Four major adjuvant trials compared trastuzumab treatment with observation after neoadjuvant or adjuvant chemotherapy in women with high risk HER2-positive breast cancer. Results of these trials showed that trastuzumab treatment given every 3 weeks for 1 year achieved a significant improvement of disease free survival and overall survival. However, cardiac toxicity occurred more in the trastuzumab arm than in the observation arm resulting in symptomatic congestive heart failure and a significant drop in left ventricular ejection function (LVEF).

AIM OF THE STUDY

The purpose of this analysis is to evaluate cardiac toxicity of adjuvant trastuzumab treatment in 30 breast cancer patients. Study parameters were cardiac toxicity assessed by LV function, disease free survival and overall survival.

MATERIALS AND METHODS

Based on the adjuvant trials and in expectation of the reimbursement of trastuzumab in the adjuvant setting, a convention was set up between the Belgian National Institute for Health and Disability Insurance and hospital centres specialized in the treatment of breast cancer. In this convention, trastuzumab was offered to patients diagnosed with invasive, non-metastatic breast cancer with an over-expression of HER2 proven by a positive FISH test. Metastatic lymph nodes or a tumour measuring more than 10 mm had to be present. At least 4 cycles of adjuvant or neoadjuvant chemotherapy had to be given to the patient. Radiotherapy could be administered. The time interval between chemotherapy or radiotherapy and treatment with trastuzumab could not be more than 6 months. LVEF determined by MUGA scan or by ultrasonography at the start of trastuzumab treatment had to be more than 55%.

RESULTS

30 breast cancer patients were treated with adjuvant trastuzumab in our hospital between June 2006 and July 2007. All patients met the inclusion criteria. Six patients stopped trastuzumab treatment because of cardiac toxicity. All these patients had received prior anthracycline neoadjuvant or adjuvant chemotherapy. Five of these patients were found to have a LVEF < 55%, one showing symptoms of congestive cardiomyopathy.The sixth patient was diagnosed with a newly developed tricuspid valve insufficiency grade 3. Follow-up data of 20 months since the start of trastuzumab treatment showed that 27 patients were disease-free. Two patients died because of progressive breast cancer disease. One patient was lost of follow-up.

CONCLUSION

In this small group of breast cancer patients, treated with adjuvant trastuzumab, cardiac toxicity expressed as a decreased left ventricular function seems to have a higher incidence compared to the other adjuvant trials. Therefore, a close cardiac monitoring for several years should be recommended in patients treated with trastuzumab.

[Management of COPD in community pharmacy]

BACKGROUND

This observational study aimed to provide a detailed description of (i) drug therapy, (ii) drug adherence, (iii) inhalation technique, and (iv) health status of COPD patients recruited via community pharmacies. Based on these results, problem areas can be detected and targeted pharmacist interventions for improvement of COPD management could be developed.

METHOD

We conducted a cross-sectional, observational study in 93 pharmacies (Belgium). Participants (n = 555) completed a questionnaire collecting personal characteristics, smoking history, influenza vaccination, COPD medication and side effects. Adherence to COPD maintenance medication was analysed 1 year-retrospectively through prescription refill rates. Inhalation technique was scored using a checklist.

RESULTS

The COPD patients had a mean age of 68.6 yr, 73.7% were men and 37.2% were current smokers. The influenza vaccination status was significantly lower in patients aged < 65 yr (65.7%) than in patients aged > or = 65 years (86.2%) (p < 0.001). Fixed combinations of inhaled corticosteroids and long-acting beta2-agonists were the most frequently used COPD medications (75.4%). About 48% of patients was underadherent (< 80% adherence), 47% was adherent (80-120% adherence) and 5% was overadherent (> 120% adherence). Twenty-one % of patients made major inhalation technique errors with rescue medication; these were all errors in handling pressurized metered dose inhalers (pMDI's).

CONCLUSION

This study on COPD management in primary care highlights 4 main aspects which could be improved: (i) drug adherence, (ii) inhalation technique with pMDI's, (iii) influenza vaccination in COPD patients < yr and (iv) smoking cessation.

The paradox of scored tablets: a cost-saving risk

One of the cornerstones of pharmacotherapy is the proper dose of medicine, which should ideally be tailored to the individual patient. However, even if clinically possible, this is economically not feasible as a too large number of different dosage strengths would be required. Therefore, a balance is required between the patient's benefit/risk and the cost to the individual and society on the other hand. Scored or splitted tablets were, and still are, often used strategies to these opposite interests, enabling more dose-flexibility, but also at the same time increasing the dose-variability as a consequence of the breaking process. The question of how to deal with this paradox was investigated by exploring the prevalence and classification of scored tablets as well as the cost-benefits. A strategy for clinical pharmacologists is presented to improve the outcome of this paradox.

[The good use of home blood pressure monitoring. Consensus document]

Self or home blood pressure measurement (HBPM) is increasingly popular. Its prognostic value and clinical interest in the diagnosis and follow-up of hypertension are well established. In addition, experts widely agree on the fact that it improves hypertension management and therapeutic compliance. In particular, HBPM often allows to detect white coat hypertension (to be confirmed by 24-hour ambulatory blood pressure measurement). Unfortunately, a large part of HBPM devices in the European Union have not fulfilled independent validation criteria. Furthermore, many patients buy and use such devices without medical supervision. This consensus document summarizes the advantages and disadvantages of HBPM and the conditions of a proper use, in agreement with the recent European and American guidelines.

Safety and availability of dapivirine (TMC120) delivered from an intravaginal ring

Vaginal delivery of 200 mg or 25 mg dapivirine from intravaginal rings (IVRs) was evaluated over a 7-day period in two phase 1 safety trials (IPM001 and IPM008, respectively) in a total of 25 healthy women 19 to 46 years of age. The IVR was generally safe and well tolerated with similar adverse events observed in the placebo and dapivirine groups. Across both studies, dapivirine concentrations in vaginal fluids measured at the introitus, cervix, and ring area were within the mean range of 0.7-7.1 microg/ml. Mean dapivirine concentrations in vaginal and cervical tissues on day 7 were 0.3-0.7 microg/g in IPM001 and 1.5-3.5 microg/g in IPM008. Mean plasma concentrations of dapivirine were <50 pg/ml. Dapivirine from both IVRs was successfully distributed throughout the lower genital tract at concentrations >1000x the EC(50) against wild-type HIV-1 (LAI) in MT4 cells suggesting that IVR delivery of microbicides is a viable option meriting further study.

Naftidrofuryl for intermittent claudication: meta-analysis based on individual patient data

OBJECTIVE

To assess the efficacy of naftidrofuryl compared with placebo in treating the symptoms of intermittent claudication.

DESIGN

Meta-analysis based on individual patient data.

DATA SOURCES

Medline, International Pharmaceutical Abstracts, Embase, Science Citation Index, and the Cochrane trial registers. Reference lists of retrieved articles were checked. Authors and companies were approached for additional information and individual patient data.

INCLUSION CRITERIA

Double blind, randomised controlled trials in patients with intermittent claudication receiving oral naftidrofuryl or placebo and with pain-free walking distance as primary outcome.

DATA COLLECTION

Individual patient data were collected from electronic data or from case report forms and checked for integrity.

ANALYSIS

All randomised patients were analysed following the intention to treat principle. Efficacy was assessed by the ratio of geometric mean of the relative improvement in pain-free walking distance after use of naftidrofuryl compared with placebo. In the analysis of responders, therapeutic success was defined as an improvement of walking distance at baseline by at least 50%.

RESULTS

In total, 1266 patients were randomised (1083 in the main analysis). The ratio of relative improvement in pain-free walking distance after use of naftidrofuryl compared with placebo was 1.37 (95% confidence interval 1.27 to 1.49). The difference in response rate was 22.3% (95% confidence interval 17.1% to 27.6%) and the number needed to treat for relief of symptoms during six months of treatment was 4.48 (95% confidence interval 3.62 to 5.85).

CONCLUSION

This meta-analysis of individual patient data provides evidence that naftidrofuryl has a clinically meaningful effect compared with placebo in improving walking distance in patients with intermittent claudication.

Symposium "Clinical Pharmacology Anno 2008". 10th Heymans Memorial Lecture

Genetic factors have been suggested depending on the drug, to account for 20 to 95 % of the variability in drug disposition and effects. Pharmacogenetics is defined as the study of interindividual variations in DNA sequence related to drug disposition or drug action that can influence clinical response. In contrast, pharmacogenomics is defined more broadly as the application of genomics to elucidate disease susceptibility, drug discovery, pharmacological function, drug disposition and therapeutic response. The best recognized examples of genetic polymorphisms that influence drug response in humans are highly penetrant monogenic traits of drug metabolizing enzymes (DME). Inherited difference in a single gene of DME has such a profound effect on the pharmacokinetics of a drug resulting in more than a 100 fold difference in systemic drug exposure with clinically important effect on drug response. Loss of function or gene duplication of DME genes have been identified as mechanisms of severe and life-threatening toxicity and poor treatment response, respectively. There is a growing list of genetic polymorphisms in drug transporters and targets that have been shown to influence drug response. However, drug response involves many genes and therefore new strategies are needed to identify, for a given drug, the relevant genes and genetic polymorphisms and the pathways and processes in their interaction. These new strategies include genome-wide haplotype mapping, gene expression analyses, proteomic methods. In addition nongenetic factors will modify drug response. A major limitation in implementing pharmacogenetic testing in the clinical setting is the lack of clinical trials demonstrating that such testing can improve drug therapy by reducing toxicity and increasing efficacy.

Naftidrofuryl for intermittent claudication

BACKGROUND

Lifestyle changes and cardiovascular prevention measures are a primary treatment for intermittent claudication (IC). Symptomatic treatment with vasoactive agents (Anatomic Therapeutic Chemical Classification (ATC) for medicines from the World Health Organisation class CO4A) is controversial.

OBJECTIVES

To evaluate evidence on the efficacy and safety of oral naftidrofuryl (ATC CO4 21) versus placebo on the pain-free walking distance (PFWD) of people with IC by using a meta-analysis based on individual patient data (IPD).

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group searched their Trials Register (last searched December 2007) and CENTRAL (last searched 2007, Issue 4). We searched MEDLINE, EMBASE, International Pharmaceutical Abstracts, the Science Citation Index and contacted the authors and checked the reference lists of retrieved articles. We asked the manufacturing company for IPD.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) with low or moderate risk of bias for which the IPD were available.

DATA COLLECTION AND ANALYSIS

We collected data from the electronic data file or from the case report form and checked the data by a statistical quality control procedure. All randomized patients were analyzed following the intention-to-treat (ITT) principle. The geometric mean of the relative improvement in PFWD was calculated for both treatment groups in all identified studies. The effect of the drug was assessed compared with placebo on final walking distance (WDf) using multilevel and random-effect models and adjusting for baseline walking distance (WD0). For the responder analysis, therapeutic success was defined as an improvement of walking distance of at least 50%.

MAIN RESULTS

We included seven studies in the IPD (n = 1266 patients). One of these studies (n = 183) was only used in the sensitivity analysis so that the main analysis included 1083 patients. The ratio of the relative improvement in PFWD (naftidrofuryl compared with placebo) was 1.37 (95% confidence interval (CI) 1.32 to 1.51, P < 0.001). The absolute difference in responder rate, or proportion successfully treated, was 22.3% (95% CI 17.1% to 27.6%). The calculated number needed to treat was 4.5 (95% CI 3.6 to 5.8).

AUTHORS' CONCLUSIONS

Naftidrofuryl has a statistically significant and clinically meaningful effect of improving walking distance in the six months after initiation of therapy for people with intermittent claudication. Access by researchers to data from RCTs that is suitable for IPD analysis should be possible through repositories of data from pharmacological trials. Regular formal appraisal of the balance of risk and benefit is needed for older pharmaceutical products.

Effectiveness of pharmacist intervention for asthma control improvement

Education on optimal medication use is an essential strategy to improve asthma control. The current authors investigated whether pharmacist interventions, focused on appropriate use of asthma medication and tailor-made to the patient's current asthma control, would improve asthma control in adult patients. A 6-month randomised, controlled, parallel-group trial was conducted in 66 community pharmacies in Belgium. Patients were randomly assigned to receive usual pharmacist care (n = 94) or a pre-defined pharmacist intervention (n = 107). This intervention mainly focused on improving inhalation technique and medication adherence. Primary outcome was the level of asthma control, as assessed by the Asthma Control Test (ACT). Mean ACT scores did not change from baseline for both study groups. However, a pre-defined subgroup analysis of patients having insufficiently controlled asthma at baseline showed that the intervention had significantly increased the ACT score after 6 months compared with usual care. The intervention also reduced, for the complete study group, reliever medication use and the frequency of night-time awakenings due to asthma. Inhalation technique and adherence to controller medication were significantly better in the intervention group. In conclusion, pragmatic community pharmacy-based programmes can significantly improve therapeutic outcomes in adult asthma patients.

Medication use and disease control of asthmatic patients in Flanders: a cross-sectional community pharmacy study

The aim of this study was to describe medication use and disease management of asthmatic patients and to evaluate the usefulness of the Asthma Control Test (ACT) in community pharmacies. In 54 Flemish community pharmacies 166 asthmatic patients were included in the study. At inclusion, the study persons completed a survey to assess subject characteristics, symptoms and asthma attacks, and peak expiratory flow (PEF) was measured. Furthermore, the actual level of asthma control was assessed by ACT, a clinically validated measure of asthma control. Prescribed medicine data of the patients were 1 year retrospectively analysed from the prescriptions. Mean age of the sample was 36.8 year, 23% were smokers. As maintenance treatment, 63% of the patients used a combination product containing an inhaled corticosteroid and a long-acting beta2-agonist in a single inhaler. According to ACT, 49.1% of the patients were insufficiently controlled. Only 4.9% of the patients had a maximal ACT score of 25, indicating complete asthma control; 46.0% of the study population obtained an ACT score between 20 and 24, meaning that their asthma is well controlled. In contrast, 30.7% of the patients had a score between 15 and 19, indicating uncontrolled asthma. In all, 18.4% obtained ACT scores of less than 15, meaning that their asthma was seriously out of control and necessitating referral to their general practitioner or lung specialist. Importantly, the correlation between the self-perceived level of asthma control and the objective assessment of the asthma control level was poor: 82.3% of the patients believed their asthma to be totally or well controlled, while this was the fact for only 50.9% of the patients. In conclusion, the ACT appears to be a useful tool to determine rapidly and accurately the level of asthma control in patients presenting at community pharmacies.

Human bioavailability of propranolol from a matrix-in-cylinder system with a HPMC-Gelucire® core

The bioavailability of propranolol from a matrix-in-cylinder system for sustained drug delivery, consisting of a hot-melt extruded ethylcellulose pipe surrounding a drug-containing HPMC-Gelucire 44/14 core, was determined. An oral dose of 80 mg propranolol hydrochloride was administered to healthy volunteers (n = 10) in a randomized cross-over study design either as a commercial pellet formulation (Inderal retard mitis) or as a matrix-in-cylinder system. The influence of concomitant food intake on drug release from the matrix-in-cylinder system was also studied. During the first 10 h after administration, the matrix-in-cylinder system resulted in similar plasma levels as the reference formulation Inderal. The concomitant intake of a high-fat, high-calorie breakfast did not cause dose-dumping. Between 10 h and 24 h after administration of the matrix-in-cylinder system, a remarkable increase of the propranolol plasma levels was noticed (compared to Inderal). This effect was even more pronounced under fed conditions. The matrix-in-cylinder system had a relative bioavailability of 156% (fasted conditions) and 222% (fed conditions) compared to the marketed reference product. In order to elucidate the origin of this increased bioavailability, Caco-2 experiments and dog lymph studies were performed. However, none of these experiments was able to provide a conclusive answer.

Pharmacotherapy of depression in old age

This review addresses the pharmacotherapy of antidepressants in the elderly. We performed a search based on Medline and the Cochrane Library. In addition to a meta-analysis of 17 randomised controlled studies, 36 randomised controlled trials of patients over the age of 60 published between 1980 and 2005 in English met the selection criteria and were included. Existing evidence suggests that no one class of antidepressant drugs has been found to be more effective than another in the treatment of depression in the elderly. Although newer antidepressants are not more effective than older ones, they are better tolerated and are safe especially in overdose. The adverse effect data suggest modest superiority of selective serotonin reuptake inhibitors over tricyclic antidepressants. The evidence available indicates that antidepressant treatment of four weeks has a beneficial effect compared to placebo. As to prevention of relapse and recurrence, antidepressants should be continued for at least six months after good initial response. In patients with high risk of relapse, treatment should be continued for at least two years. Long-term efficacy has been shown for dosulepin, nortriptyline and citalopram. In patients with dementia with persistent and significant symptoms antidepressant treatment may be indicated. At present, clomipramine, citalopram and sertraline have been reported as being superior to placebo. There is a paucity of data on the use of antidepressants in very elderly individuals, patients with significant comorbidity and patients with dementia. More data on the effect of antidepressants in the elderly, especially in the over 80-age group are needed.

Drug formulations intended for the global market should be tested for stability under tropical climatic conditions

RATIONALE OBJECTIVE

The quality of drugs imported into developing countries having a tropical climate may be adversely affected if their formulations have not been optimized for stability under these conditions. The present study investigated the influence of tropical climate conditions (class IV: 40 degrees C, 75% relative humidity) on the drug content, in vitro dissolution and oral bioavailability of different formulations of two essential drugs marketed in Tanzania: diclofenac sodium and ciprofloxacin tablets.

METHODS

Before and after 3 and 6 months storage under class IV conditions the drug content and in vitro dissolution were evaluated using United States Pharmacopoeia (USP) 24 methods. Following a randomized four-period cross-over study, the pharmacokinetic parameters of drug formulations stored for 3 months under class IV conditions were compared with those stored at ambient conditions.

RESULTS

Drug content and drug release from all tested ciprofloxacin formulations were within USP-24 requirements and remained stable during storage at simulated tropical conditions. Oral bioavailability was also not influenced by tropical conditions. The dissolution rate of two diclofenac formulations (Diclo 50 manufactured by Camden and Dicloflame 50 manufactured by Intas) reduced significantly during storage under class IV conditions. After oral administration Camden tablets stored for 3 months under class IV conditions showed a reduction in C(max) (90% CI of C(max) ratio: 0.59 - 0.76). This reduction was smaller than expected based on the in vitro tests.

CONCLUSIONS

Some drug formulations imported into Tanzania are not optimized for stability in a tropical climate. Manufacturers and regulatory authorities should pay more attention to the WHO recommendations for testing the stability of drugs under tropical climate conditions. Efforts should be made to improve the in vitro tests to better predict the bioavailability.

In vitro and in vivo evaluation of starch-based hot stage extruded double matrix systems

The objective of developing a double matrix system consisting of a hot stage extruded starch pipe surrounding a hot stage extruded and drug-containing starch core, was to obtain a monolithic matrix system applicable in the domain of sustained drug release. The behaviour of the systems was evaluated through dissolution testing and through a randomised crossover bioavailability study on nine male volunteers. All double matrix systems showed in vitro a nearly constant drug release profile after an initial slower release phase of 4 h. This initial slower release phase was avoided by loading the starch pipe with a small amount of drug. The in vitro dissolution profiles did not reflect the in vivo behaviour of the systems. Although the in vitro dissolution profiles of two selected double matrix systems were slower than the profile of a commercially available sustained release formulation, they performed less well in vivo. However, the t75%Cmax ratios of the evaluated double matrix systems versus a reference immediate release formulation indicated an acceptable sustained release behaviour, superior to that of hot stage extruded starch-based single matrices. Therefore the disclosed drug delivery systems could be applied in the domain of sustained drug delivery. Besides, the continuous production of the double matrix systems offers an advantage from a manufacturing point of view.

Population analysis of the non linear red blood cell partitioning and the concentration-effect relationship of draflazine following various infusion rates

AIMS

To investigate the impact of the specific red blood cell binding on the pharmacokinetics and pharmacodynamics of the nucleoside transport inhibitor draflazine after i.v. administration at various infusion rates. It was also aimed to relate the red blood cell (RBC) occupancy of draflazine to the ex vivo measured adenosine breakdown inhibition (ABI).

METHODS

Draflazine was administered to healthy volunteers as a 15-min i.v. infusion of 0.25, 0.5, 1, 1.5 and 2.5 mg immediately followed by an infusion of the same dose over 1 h. Plasma and whole blood concentrations were measured up to 120 h post dose, and were related to the ex vivo measured ABI, serving as a pharmacodynamic endpoint. The capacity-limited specific binding of draflazine to the nucleoside transporter located on the erythrocytes was evaluated by a population approach.

RESULTS

The estimate of the population parameter typical value (%CV) of the binding constant Kd and the maximal specific binding capacity (Bmax) was 0.385 (3.5) ng ml-1 plasma and 158 (2.1) ng ml-1 RBC, respectively. The non-specific binding was low. The specific binding to the erythrocytes was a source of non-linearity in the pharmacokinetics of draflazine. The total plasma clearance of draflazine slightly decreased with increasing doses, whereas the total clearance in whole blood increased with increasing doses. The sigmoidal Emax equation was used to relate the plasma and whole blood concentration of draflazine to the ex vivo determined ABI. In plasma, typical values (%CV) of Emax, IC50 and Hill factor were 81.4 (1.9)%, 3.76 (9.3) ng ml-1 and 1.06 (3.4), respectively. The relationship in whole blood was much steeper with population parameter typical values (%CV) of Emax, IC50 and Hill factor of 88.2 (2.0)%, 65.7 (2.8) ng ml-1 and 4.47 (5.5), respectively. The RBC occupancy of draflazine did not coincide with the ex vivo measured ABI. The observed relationship between RBC occupancy and ABI was not directly proportional but similar for all studied infusion schemes.

CONCLUSIONS

The findings of this study show that the occupancy of the nucleoside transporter by draflazine should be at least 90% in order to inhibit substantially adenosine breakdown in vivo. On the basis of these findings it is suggested that a 15 min infusion of 1 mg draflazine followed by an infusion of 1 mg h-1 could be appropriate in patients undergoing a coronary artery bypass grafting.

Does lowering of cholesterol levels influence functional properties of large arteries?

Hypercholesterolaemia is a risk factor for atherosclerosis and induces endothelial dysfunction. Endothelial dysfunction may increase vascular tone and arterial stiffness and as a consequence may decrease arterial distensibility (DC) and arterial compliance (CC). It is hypothesized that lipid-lowering therapy may enhance DC and CC. Therefore, the present study investigates the effect of lipid-lowering therapy with pravastatin on the haemodynamics, DC and CC of the elastic common carotid artery (CCA), and the muscular femoral (FA) and brachial (BA) arteries in patients with primary hypercholesterolaemia. After an 8-week placebo run-in period with a low-cholesterol diet, 19 patients with total cholesterol concentrations of between 6.5 and 9.0 mmol.l-1 and triglyceride concentrations < 4 mmol.l-1 entered a double-blind placebo controlled crossover study. Patients received pravastatin 40 mg o.d. or placebo, each for 8 weeks. Throughout the study the lipid-lowering diet was continued. With pravastatin, total cholesterol, low-density lipoprotein cholesterol (LDL-C) and triglycerides were decreased (total cholesterol 26%, LDL-C 35%, triglycerides 16%), while high-density lipoprotein cholesterol (HDL-C) was not changed. Other laboratory values remained within the normal range. Blood pressure, heart rate, cardiac function and systemic vascular resistance were not influenced by pravastatin. Compared to placebo, diameter, distensibility and compliance of all arteries were not statistically significantly changed with pravastatin. These data suggest that, in patients with mild to moderate primary hypercholesterolaemia, short-term lowering of plasma cholesterol does not alter the haemodynamics and vessel wall properties of large arteries.

The effect of verapamil on carotid artery distensibility and cross-sectional compliance in hypertensive patients

The effect of chronic administration of verapamil, following a double-blind, crossover protocol, on the distensibility and cross-sectional compliance of the common carotid artery was investigated in 19 patients with essential hypertension. Distensibility was significantly increased during verapamil treatment as compared to placebo for both left and right common carotid artery (p less than 0.01 and p less than 0.05, respectively). The cross-sectional compliance was significantly increased during verapamil treatment for the right common carotid artery (p less than 0.05). For the left common carotid artery, the difference did not reach the level of significance (p = 0.16). The common carotid artery diameter and the arterial pulse pressure were not significantly different during verapamil treatment as compared with placebo. The results of this study indicate that chronic treatment with verapamil increases distensibility and cross-sectional compliance of the common carotid artery in hypertensive subjects. These improvements have to be considered as changes in arterial wall properties because no significant differences in pulse pressure and diameter could be detected between the verapamil and placebo periods. Improved arterial wall properties could result in a better management of the flow jet from the heart, and might protect the patients from atherosclerotic complications of hypertension.