Systematic review: Helicobacter pylori infection and impaired drug absorption

Helicobacter pylori infection is a risk factor for constipation in patients with Parkinson's disease: A multicenter prospective cohort study

BACKGROUND AND AIMS

Constipation is one of the most common nonmotor symptoms (NMSs) of Parkinson's disease (PD). The infection rate of Helicobacter pylori (HP) is greater in PD patients. This study was a multicenter prospective cohort study in which propensity score matching (PSM) was used to determine whether HP infection was a risk factor for constipation in patients with PD.

METHODS

A total of 932 PD patients with 13C-urea breath test for HP were included in the study. The PSM was estimated with the use of a nonparsimonious multivariate logistic regression model, with HP infection as the dependent variable and all the baseline characteristics as covariates. A total of 697 patients composed the study cohort, including 252 (36.2 %) patients in the HP-positive (HPP) group and 445 (63.8 %) patients in the HP-negative (HPN) group. Before PSM, there were differences in several of the baseline variables between the two groups. After PSM, 250 HPP patients were matched with 250 HPN patients and the standardized differences were less than 0.1 for all variables.

RESULTS

The present results demonstrate that HP infection is a risk factor for constipation in patients with PD [RR (95 % CI) 1.412 (1.155-1.727), P < 0.001]. Subgroup analyses revealed that HP infection was both a risk factor for constipation in Hoehn-Yahr scale (1,1.5) group and Hoehn-Yahr scale (2-5) group [OR (95 % CI) 1.811 (1.079-3.038), P < 0.025; OR (95 % CI) 2.041 (1.177-3.541), P < 0.011].

CONCLUSIONS

The results of our prospective cohort study suggest that Helicobacter pylori infection is a risk factor for constipation in patients with PD.

TRIAL REGISTRATION

ChiCTR2300071631.

New Drug Delivery Systems for Stable Oral Absorption: Theory, Strategies, and Applications

The oral dosage route still remains the most common and preferred route for drug administration due to convenient handling, high patient compliance, and cost-effectiveness. However, the oral absorption of drugs can be a complex process depending upon: (i) physicochemical properties of the drug (e.g., pKa, lipophilicity, solubility), (ii) pharmaceutical factors (e.g., dosage form), and (iii) physiological factors (e.g., gastrointestinal pH values, gastric emptying rate, gastric and intestinal pH, metabolism). Oral administration of drugs sometimes leads to poor and/or variable oral bioavailability, possible leading to unstable clinical outcomes. To offer stable and improved pharmacokinetic behavior of drugs, a number of formulation approaches have been developed with a focus on enhancement of the solubility, dissolution rate, and oral bioavailability of drugs. To provide new formulation platforms for better and safe medication, it is considered essential to understand the physicochemical, biochemical, metabolic, and biological barriers which limit overall drug bioavailability in more detail. The review article considers several crucial factors affecting oral absorption of drug substances. This article also describes the recent progress in formulation approaches to achieve stable and improved biopharmaceutical properties of orally-taken drugs.

Review of Phytochemical Potency as a Natural Anti-Helicobacter pylori and Neuroprotective Agent

Phytochemicals are plant secondary metabolites that show health benefits for humans due to their bioactivity. There is a huge variety of phytochemicals that have already been identified, and these compounds can act as antimicrobial and neuroprotection agents. Due to their anti-microbial activity and neuroprotection, several phytochemicals might have the potency to be used as natural therapeutic agents, especially for Helicobacter pylori infection and neurodegenerative disease, which have become a global health concern nowadays. According to previous research, there are some connections between H. pylori infection and neurodegenerative diseases, especially Alzheimer's disease. Hence, this comprehensive review examines different kinds of phytochemicals from natural sources as potential therapeutic agents to reduce H. pylori infection and improve neurodegenerative disease. An additional large-scale study is needed to establish the connection between H. pylori infection and neurodegenerative disease and how phytochemicals could improve this condition.

Microorganisms associated with increased risk of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that affects more than 7 million people worldwide. Its aetiology is unknown, although the hypothesis of a genetic susceptibility to environmental agents is accepted. These environmental agents include fungi, bacteria, and viruses. Three microorganisms are directly associated with a significantly increased risk of developing Parkinson's disease: the fungal genus Malassezia, the bacterium Helicobacter pylori, and the hepatitis C virus. If the host is vulnerable due to genetic susceptibility or immune weakness, these microorganisms can access and infect the nervous system, causing chronic neuroinflammation with neurodegeneration. Other microorganisms show an epidemiological association with the disease, including the influenza type A, Japanese encephalitis type B, St Louis, and West Nile viruses. These viruses can affect the nervous system, causing encephalitis, which can result in parkinsonism. This article reviews the role of all these microorganisms in Parkinson's disease.

Impact of outpatient gastroenterology consult on pharmacotherapy and management of gastrointestinal symptoms in Parkinson's Disease

Background & aims

Gastrointestinal (GI) symptoms are common in Parkinson's Disease (PD) patients, and GI dysmotility is thought to induce motor fluctuations, requiring escalation of levodopa therapy. The role of GI consultation in managing such symptoms, however, is unclear. In this study, we investigate the possible association between GI dysmotility symptoms and escalated LEDD therapy, as well as factors associated with GI consultation for PD symptom management.

Methods

This was a retrospective case-study of 248 PD patients evaluated by outpatient neurology at Massachusetts General Brigham Healthcare from 2018 to 2022. Logistic regression, t-test, and Fisher exact tests were performed to identify factors associated with GI consult, change in LEDD with consult, and association of consultation with GI diagnoses and treatments, respectively.

Results

Among 248 PD patients, 12.9% received GI consultation despite 96.8% having GI symptoms. Bloating was the primary symptom associated with receiving GI consultation (OR 3.59 [95% CI 1.47-8.88], p = 0.005). GI consultation increased the odds of receiving GI-specific medications (78.2% vs 46.3%, p = 0.001) and specialized GI diagnoses like gastroparesis (9.4% vs 0.46%, p < 0.001) and pelvic floor dysfunction (15.6% vs 0%, p < 0.0001). Interestingly, LEDD tended not to change after GI consultation, and dysmotility symptoms, including bloating, did not predict need for higher LEDD.

Conclusions

While treating symptoms of dysmotility may not ameliorate levodopa-based motor fluctuations as much as previously thought, GI consultations are underutilized in PD, and patients who receive GI consultation are more likely to have changes in GI diagnosis and treatment.

The Role of Pathogens and Anti-Infective Agents in Parkinson's Disease, from Etiology to Therapeutic Implications

Parkinson's disease is a debilitating neurodegenerative disorder whose etiology is still unclear, hampering the development of effective treatments. There is an urgent need to identify the etiology and provide further effective treatments. Recently, accumulating evidence has indicated that infection may play a role in the etiology of Parkinson's disease. The infective pathogens may act as a trigger for Parkinson's disease, the most common of which are hepatitis C virus, influenza virus, and Helicobacter pylori. In addition, gut microbiota is increasingly recognized to influence brain function through the gut-brain axis, showing an important role in the pathogenesis of Parkinson's disease. Furthermore, a series of anti-infective agents exhibit surprising neuroprotective effects via various mechanisms, such as interfering with α-synuclein aggregation, inhibiting neuroinflammation, attenuating oxidative stress, and preventing from cell death, independent of their antimicrobial effects. The pleiotropic agents affect important events in the pathogenesis of Parkinson's disease. Moreover, most of them are less toxic, clinically safe and have good blood-brain penetrability, making them hopeful candidates for the treatment of Parkinson's disease. However, the use of antibiotics and subsequent gut dysbiosis may also play a role in Parkinson's disease, making the long-term effects of anti-infective drugs worthy of further consideration and exploration. This review summarizes the current evidence for the association between infective pathogens and Parkinson's disease and subsequently explores the application prospects of anti-infective drugs in Parkinson's disease treatment, providing novel insights into the pathogenesis and treatment of Parkinson's disease.

Microbial Infections Are a Risk Factor for Neurodegenerative Diseases

Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, comprise a family of disorders characterized by progressive loss of nervous system function. Neuroinflammation is increasingly recognized to be associated with many neurodegenerative diseases but whether it is a cause or consequence of the disease process is unclear. Of growing interest is the role of microbial infections in inciting degenerative neuroinflammatory responses and genetic factors that may regulate those responses. Microbial infections cause inflammation within the central nervous system through activation of brain-resident immune cells and infiltration of peripheral immune cells. These responses are necessary to protect the brain from lethal infections but may also induce neuropathological changes that lead to neurodegeneration. This review discusses the molecular and cellular mechanisms through which microbial infections may increase susceptibility to neurodegenerative diseases. Elucidating these mechanisms is critical for developing targeted therapeutic approaches that prevent the onset and slow the progression of neurodegenerative diseases.

Drug Response Diversity: A Hidden Bacterium?

Interindividual heterogeneity in response to treatment is a real public health problem. It is a factor that can be responsible not only for ineffectiveness or fatal toxicity but also for hospitalization due to iatrogenic effects, thus increasing the cost of patient care. Several research teams have been interested in what may be at the origin of these phenomena, particularly at the genetic level and the basal activity of organs dedicated to the inactivation and elimination of drug molecules. Today, a new branch is being set up, explaining the enigmatic part that could not be explained before. Pharmacomicrobiomics attempts to investigate the interactions between bacteria, especially those in the gut, and drug response. In this review, we provide a state of the art on what this field has brought as new information and discuss the challenges that lie ahead to see the real application in clinical practice.

Helicobacter pylori infection is associated with a poor response to levodopa in patients with Parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (HP) infection has been reported to be associated with increased severity of Parkinson's disease (PD) and have negative effects on drug response in patients. We aimed to investigate the influence of HP infection on patients with PD using a systematic review and meta-analysis approach.

METHODS

PubMed and EMBASE databases for relevant articles published before October 2020 were searched. Two authors independently screened records, extracted data, and evaluated the quality of the included studies. The odds ratios (ORs) or standardized mean differences (SMDs) with their corresponding 95% confidence intervals (CIs) were used to calculate the pooled results by employing a random or fixed-effects model. Sensitivity analyses were conducted, and potential publication bias was assessed.

RESULTS

A total of 13 studies were included in our meta-analysis. Overall, PD patients with HP infection had significantly higher levodopa equivalent daily dose (UPDRS) motor scores (SMD = 0.266; 95% CI 0.065-0.467; P = 0.009) and more units of levodopa equivalent daily dose (LEDD) (SMD = 0.178; 95% CI 0.004-0.353; P = 0.046) than those of patients without HP infection. Additionally, the time to achieve 'ON' state was significantly longer (SMD = 0.778; 95% CI 0.337-1.220; P = 0.001) and the duration of 'ON' state was significantly shorter (SMD = -0.539; 95% CI = -0.801 to  -0.227; P = 0.001) in patients with HP infection than in those without HP infection.

CONCLUSION

Our pooled results of this meta-analysis demonstrated that HP infection was associated with worse motor symptoms, higher LEDD, and worse response to drugs in patients with PD. This evidence emphasizes the importance of considering subsequent eradication of HP infection in patients with PD.

Microorganisms that are related with increased risk for Parkinson's disease

Parkinson's disease is a neurodegenerative disorder that affects more than 7 million people worldwide. Its aetiology is unknown, although the hypothesis of a genetic susceptibility to environmental agents is accepted. These environmental agents include fungi, bacteria, and viruses. Three microorganisms are directly associated with a significantly increased risk of developing Parkinson's disease: the fungal genus Malassezia, the bacterium Helicobacter pylori, and the hepatitis C virus. If the host is vulnerable due to genetic susceptibility or immune weakness, these microorganisms can access and infect the nervous system, causing chronic neuroinflammation with neurodegeneration. Other microorganisms show an epidemiological association with the disease, including the influenza type A, Japanese encephalitis type B, St Louis, and West Nile viruses. These viruses can affect the nervous system, causing encephalitis, which can result in parkinsonism. This article reviews the role of all these microorganisms in Parkinson's disease.

Microbiome and motor neuron diseases

The microbiome is the ecological community of commensal, symbiotic, and pathogenic microorganisms that share our body space (Medical and Health Genomics, 2016, page 15-28). The human gut is the location where the maximum number of microorganisms can be found. Among the different microorganisms they can be broadly classified into two groups: the beneficial and harmful. In the human gut there is always a balance between the beneficial and the opportunistic microorganism which maintains human health. However, if the balance is not maintained and homeostasis is disturbed, with an increase in opportunistic microorganisms, it may result in various diseases like inflammatory bowel disease, irritable bowel disease, ulcerative colitis, Crohn's disease, colorectal cancer, metabolic disorders and neurodegenerative diseases including motor neuron diseases. In the present chapter we discuss the role of gut bacteria in motor neuron diseases like multiple sclerosis, Parkinson's disease and amyotrophic lateral sclerosis.

Contributions of Gut Bacteria and Diet to Drug Pharmacokinetics in the Treatment of Parkinson's Disease

Parkinson's disease is the second-most common neurodegenerative disorder worldwide. Besides deciphering the mechanisms that underlie the etiology of the disease, it is important to elucidate the factors that influence the efficacy of the treatment therapeutics. Levodopa, which remains the golden treatment of the disease, is absorbed in the proximal small intestine. A reduction in levodopa absorption, leads to reduction in striatal dopamine levels and, in turn, an "off"-episode. In fact, motor fluctuations represent a major problem during the progression of the disease and alteration between "on" (mobility often with dyskinesia) and "off" (immobility, akinesia) episodes contribute to a decreased quality of life. Dietary amino acids can interfere with the absorption of levodopa from the gut lumen and its transport through the blood brain barrier. In addition, higher abundance of specific gut bacteria that restrict levodopa absorption plays a significant role in motor fluctuations in a subset of Parkinson's disease patients. Here, we review the impact of factors potentially interfering with levodopa absorption, focusing on levodopa transport, diet, and gut bacterial interference with the bioavailability of levodopa.

Houston Consensus Conference on Testing for Helicobacter pylori Infection in the United States

Despite guidelines for detection and treatment of Helicobacter pylori infection, recommendations to test patients before and after therapy are commonly not followed in the United States. At the Houston Consensus Conference, 11 experts on management of adult and pediatric patients with H pylori, from different geographic regions of the United States, met to discuss key factors in diagnosis of H pylori infection, including identification of appropriate patients for testing, effects of antibiotic susceptibility on testing and treatment, appropriate methods for confirmation of infection and eradication, and relevant health system considerations. The experts divided into groups that used a modified Delphi panel approach to assess appropriate patients for testing, testing for antibiotic susceptibility and treatment, and test methods and confirmation of eradication. The quality of evidence and strength of recommendations were evaluated using the GRADE system. The results of the individual workshops were presented for a final consensus vote by all panel members. After the Expert Consensus Development meeting, the conclusions were validated by a separate panel of gastroenterologists, who assessed their level of agreement with each of the 29 statements developed at the Expert Consensus Development. The final recommendations are provided, on the basis of the best available evidence, and provide consensus statements with supporting literature to implement testing for H pylori infection at health care systems across the United States.

MANAGEMENT OF ENDOCRINE DISEASE: Pitfalls on the replacement therapy for primary and central hypothyroidism in adults

Hypothyroidism is one of the most common hormone deficiencies in adults. Most of the cases, particularly those of overt hypothyroidism, are easily diagnosed and managed, with excellent outcomes if treated adequately. However, minor alterations of thyroid function determine nonspecific manifestations. Primary hypothyroidism due to chronic autoimmune thyroiditis is largely the most common cause of thyroid hormone deficiency. Central hypothyroidism is a rare and heterogeneous disorder characterized by decreased thyroid hormone secretion by an otherwise normal thyroid gland, due to lack of TSH. The standard treatment of primary and central hypothyroidism is hormone replacement therapy with levothyroxine sodium (LT4). Treatment guidelines of hypothyroidism recommend monotherapy with LT4 due to its efficacy, long-term experience, favorable side effect profile, ease of administration, good intestinal absorption, long serum half-life and low cost. Despite being easily treatable with a daily dose of LT4, many patients remain hypothyroid due to malabsorption syndromes, autoimmune gastritis, pancreatic and liver disorders, drug interactions, polymorphisms in DIO2 (iodothyronine deiodinase 2), high fiber diet, and more frequently, non-compliance to LT4 therapy. Compliance to levothyroxine treatment in hypothyroidism is compromised by daily and fasting schedule. Many adult patients remain hypothyroid due to all the above mentioned and many attempts to improve levothyroxine therapy compliance and absorption have been made.

Stomaching the Possibility of a Pathogenic Role for Helicobacter pylori in Parkinson's Disease

While a small subset of Parkinson's disease cases have genetic causes, most cases are sporadic and may have an environmental contributor that has largely remained enigmatic. Remarkably, gastrointestinal symptoms in PD patients serve as a prodrome for the eventual motor dysfunctions. Herein, we review studies exploring a possible link between the gastric human pathogen Helicobacter pylori and PD. We provide plausible and testable hypotheses for how this organism might contribute to PD: 1) a toxin(s) produced by the bacteria; 2) disruption of the intestinal microbiome; 3) local inflammation that crosses the gut-brain axis, leading to neuroinflammation; and 4) manipulation of the pharmacokinetics of the PD drug levodopa by H. pylori, even in those not receiving exogenous levodopa. Key findings are: 1) people with PD are 1.5-3-fold more likely to be infected with H. pylori than people without PD; 2) H. pylori-infected PD patients display worse motor functions than H. pylori-negative PD patients; 3) eradication of H. pylori improves motor function in PD patients over PD patients whose H. pylori was not eradicated; and 4) eradication of H. pylori improves levodopa absorption in PD patients compared to that of PD patients whose H. pylori was not eradicated. Evidence is accumulating that H. pylori has a link with PD, but the mechanism is unclear. Future work should explore the effects of H. pylori on development of PD in defined PD animal models, focusing on the roles of H. pylori toxins, inflammation, levodopa absorption, and microbiome dysbiosis.

Helicobacter pylori infection is associated with an increased risk of Parkinson's disease: A population-based retrospective cohort study

BACKGROUND

Several studies have evaluated the association of Parkinson's disease with Helicobacter pylori (HP) infection, although no cohort studies have evaluated this association among the general population.

OBJECTIVE

This study aimed to investigate the risk of Parkinson's disease after HP infection in the general Taiwanese population.

METHODS

This study of Taiwanese health insurance data (2000-2012) evaluated 9105 cases of HP infection and 9105 controls matched with propensity scoring. Univariate and multivariate Cox proportional hazards regression models were used to assess the risk of subsequent Parkinson's disease.

RESULTS

We observed 64 cases of Parkinson's disease in the HP infection group (1.7/1000 person-years), and 25 cases in the control group (0.7/1000 person-years). Overall, there was a significantly higher risk of Parkinson's disease in the HP infection group (adjusted hazard ratio [aHR]: 2.29, 95% confidence interval [CI]: 1.44-3.66). HP infection was significantly associated with an increased risk of Parkinson's disease among individuals who were ≥60 years old (aHR: 2.53, 95% CI: 1.47-4.35), but not among those <60 years old (aHR: 1.86, 95% CI: 0.69-4.98). Furthermore, HP infection was associated with an increased risk of Parkinson's disease among both men (aHR: 2.14, 95% CI: 1.15-3.96) and women (aHR: 2.84, 95% CI: 1.37-5.89). Nonetheless, eradication therapy was not significantly associated with the risk of Parkinson's disease (aHR: 1.07, 95% CI: 0.63-1.82).

CONCLUSION

Although HP infection was associated with an increased risk of Parkinson's disease, eradication therapy did not ameliorate this association. Further research is needed to explore the underlying biological mechanisms.

Tablet and oral liquid L-thyroxine formulation in the treatment of naïve hypothyroid patients with Helicobacter pylori infection

To compare the clinical efficacy of tablet and oral liquid L-thyroxine (LT4) formulation in naïve hypothyroid subjects with Helicobacter pylori infection. Forty-seven adult naïve hypothyroid subjects with dyspeptic symptoms were investigated with upper endoscopy and divided into: 28 patients with Helicobacter pylori infection (Group A); 15 patients without gastric alterations (group B); 4 patients with autoimmune gastritis were excluded from the study. Subjects were randomly treated with a same dose of LT4 tablet (TAB) or oral liquid formulation (SOL), for 9 months on group A and 6 months on group B. Helicobacter pylori infection was eradicated after 3 months of LT4 treatment. On group A, after 3 months (before Helicobacter pylori eradication), subjects treated with SOL showed a greater thyroid-stimulating hormone reduction (ΔTSH_3-0: TAB = -4.1 ± 4.6 mU/L; SOL = -7.7 ± 2.5 mU/L; p = 0.029) and a greater homogeneity in the thyroid-stimulating hormone values (TSH_3mo: TAB = 5.7 ± 4.9 mU/L; SOL = 4.1 ± 2.0 mU/L; p = 0.025), compared to LT4 tablet. At 9 months (after 6 months of Helicobacter pylori eradication) mean thyroid-stimulating hormone values were lower in subjects treated with LT4 tablet (TSH_9mo: TAB = 1.8 ± 1.2 mU/L; SOL = 3.2 ± 1.7 mU/L; p = 0.006). On group B no difference were observed, at each time point, in the mean thyroid-stimulating hormone values and thyroid-stimulating hormone variations between two LT4 formulations. LT4 liquid formulation may produce a better clinical response compared to the tablet formulation in hypothyroid subjects with Helicobacter pylori infection.

Out-of-Reference Range Thyroid-Stimulating Hormone Levels in Levothyroxine-Treated Primary Hypothyroid Patients: A Multicenter Observational Study

OBJECTIVE

Although levothyroxine (LT4) replacement therapy for hypothyroidism has been established as safe, inexpensive and effective, many studies from different countries reported out-of-reference range thyroid-stimulating hormone (TSH) values for the hypothyroid patients under LT4 treatment. The aim of this study was to determine TSH levels of primary hypothyroid patients under LT4 treatment and to assess self-reported compliance with daily LT4 intake in tertiary care centers in Turkey.

DESIGN

In this cross-sectional, observational study, adult patients with primary hypothyroidism, receiving LT4 treatment for at least 6 months, were included. The patients were from 12 tertiary care centers in 9 cities of Turkey. TSH and free T4 levels were recorded from patient files and self-reported compliance with daily LT4 intake was assessed by interviewing the subjects at the last visit.

RESULTS

A total of 1,755 subjects (46 ± 13 years; F/M: 89.9/10.1%) with primary hypothyroidism were enrolled. Of the hypothyroid subjects, 44.8% had out-of-reference range serum TSH levels. TSH values were over the reference range (TSH > 4 mIU/L) in 26.2% and were under the reference range (TSH < 0.5 mIU/L) in 18.6% of the patients. Total duration of LT4 treatment was 5.9 ± 4.7 years and mean dose was 1.2 ± 0.6 μg/kg/day. Non-compliant patients (31.1%) had higher TSH levels (6.9 ± 16 vs 3.8 ± 0.9 mIU/L, P = 0.01) compared to compliant patients.

CONCLUSION

The results of this study revealed that nearly half of the hypothyroid patients had out-of-reference range serum TSH values, despite under LT4 treatment. Compliance with LT4 treatment seems to be one of the major determinants to reach the target TSH levels in hypothyroid patients.

Association between Parkinson's Disease and Helicobacter Pylori

Helicobacter pylori (HP) is a common infection of the gastrointestinal system that is usually related to peptic ulcers. However, recent studies have revealed relationships between HP and many other diseases. Although the exact mechanism is unknown, HP can prevent the absorption of certain drugs. A high prevalence of HP has been found in patients with Parkinson's disease, and this bacterium causes motor fluctuations by affecting the absorption of levodopa, which is the main drug used to treat Parkinson's disease. Eradicating HP from patients with Parkinson's disease by applying antibiotic treatment will increase the absorption of levodopa and decrease their motor fluctuations.

Development of pH-Independent Drug Release Formulation Using Lipocalin-Type Prostaglandin D Synthase

The purpose of this study was to develop a pH-independent drug release formulation using lipocalin-type prostaglandin D synthase, a member of the lipocalin superfamily, with the function of forming complexes together with various small lipophilic molecules. Dipyridamole, a poorly water-soluble drug, showing a pH-dependent solubility profile, was used as the model drug. The solubilization of dipyridamole was achieved by a simple complex formulation method with lipocalin-type prostaglandin D synthase. The complex formulation was produced successfully by spray drying, and the obtained powder formulation showed complete dissolution in fasted-state simulated gastric fluid (pH, 1.6) and phosphate-buffered solution (pH, 6.8). In addition, the potential stability of the complex formulation was assessed, and the dissolution profile of the produced powder at pH 6.8 was maintained after 4-week storage under several storage conditions. Furthermore, a pharmacokinetic study using hypochlorhydria model rats was performed to verify the improvement of the intestinal absorption behavior, and eventually the complex formulation overcame the problematic absorption profile of dipyridamole in the elevated gastric pH conditions. These results, taken together, demonstrate that the use of this well-designed drug-delivery carrier is feasible for the development of pH-independent drug release formulations.

Helicobacter pylori, HIV and Gastric Hypochlorhydria in the Malawian Population

BACKGROUND

HIV and Helicobacter pylori are common chronic infections in sub-Saharan Africa. Both conditions can predispose to gastric hypochlorhydria that may be a risk factor for enteric infections and reduced drug absorption. We have investigated to what extent HIV and H. pylori infections are associated with hypochlorhydria in a Malawian cohort of patients undergoing endoscopy.

METHODS

104 sequential symptomatic adults referred for gastroscopy at Queen Elizabeth Central Hospital, Blantyre, Malawi, had blood taken for rapid HIV testing and fasting serum gastrin analysis. Gastric fluid was aspirated for pH testing, and gastric biopsies were taken.

RESULTS

After 9/104 HIV-infected patients who were already established on anti-retroviral therapy were excluded, 17/95 (25.0%) were seropositive for untreated HIV, and 68/95 (71.6%) patients were H. pylori positive by histology. Hypochlorhydria (fasting gastric pH>4.0) was present in 55.8% (53/95) of patients. H. pylori infection was significantly associated with hypochlorhydria (OR 2.91, [1.02-7.75], p=0.046). While single infection with HIV was not significantly independently associated with hypochlorhydria. H. pylori and HIV co-infection was more strongly associated with hypochlorhydria (OR 6.25, [1.33-29.43], p=0.020) than either infection alone, suggesting an additive effect of co-infection. HIV infection was associated with higher serum gastrin levels (91.3 pM vs. 53.1 pM, p=0.040), while H. pylori infection was not (63.1 pM vs. 55.1 pM, p=0.610). Irrespective of H. pylori and HIV status, most patients (>90%) exhibited pangastritis. Only three patients had histological evidence of gastric atrophy, of which only one was HIV-infected.

CONCLUSION

H. pylori infection was associated with fasting hypochlorhydria, while HIV was not independently associated. HIV and H. pylori co-infection, however, was more strongly associated with hypochlorhydria than H. pylori infection alone. The mechanism of this apparent additive effect between HIV and H. pylori remains unclear, but appears to be related to chronic pangastritis rather than gastric atrophy, and associated with hypergastrinaemia in HIV-infected individuals.

Are clinical features able to predict Helicobacter pylori gastritis patterns? Evidence from tertiary centers

Outcome of Helicobacter pylori infection is different according to gastritis extension (i.e. antrum-restricted gastritis or pangastritis). The aim of this study is to evaluate whether different gastritis patterns are associated with specific gastrointestinal symptoms or clinical signs that could be suggestive of the topography of gastritis. 236 consecutive symptomatic outpatients were recruited in two tertiary centers. They filled in a validated and self-administered Rome III modular symptomatic questionnaire, and underwent gastroscopy with histological sampling. 154 patients with Helicobacter pylori infection were included. Clinical presentation did not differ between antrum-restricted gastritis and pangastritis, gastro-esophageal reflux disease being present in 48.2 and 54.1 % of patients and dyspepsia in 51.8 and 45.9 %, respectively. However, pangastritis statistically differed from antrum-restricted gastritis in that the presence of clinical signs (p < 0.0001) was observed in 33.7 % of the patients, consisting of iron deficiency (31.6 %), iron deficiency-anemia (20.4 %) and levothyroxine malabsorption (3.1 %). Symptoms are not helpful in suggesting gastritis pattern whereas their association with signs, accurately detected, is indicative for the presence of pangastritis.

Beyond the stomach: An updated view of Helicobacter pylori pathogenesis, diagnosis, and treatment

Helicobacter pylori (H. pylori) is an extremely common, yet underappreciated, pathogen that is able to alter host physiology and subvert the host immune response, allowing it to persist for the life of the host. H. pylori is the primary cause of peptic ulcers and gastric cancer. In the United States, the annual cost associated with peptic ulcer disease is estimated to be $6 billion and gastric cancer kills over 700000 people per year globally. The prevalence of H. pylori infection remains high (> 50%) in much of the world, although the infection rates are dropping in some developed nations. The drop in H. pylori prevalence could be a double-edged sword, reducing the incidence of gastric diseases while increasing the risk of allergies and esophageal diseases. The list of diseases potentially caused by H. pylori continues to grow; however, mechanistic explanations of how H. pylori could contribute to extragastric diseases lag far behind clinical studies. A number of host factors and H. pylori virulence factors act in concert to determine which individuals are at the highest risk of disease. These include bacterial cytotoxins and polymorphisms in host genes responsible for directing the immune response. This review discusses the latest advances in H. pylori pathogenesis, diagnosis, and treatment. Up-to-date information on correlations between H. pylori and extragastric diseases is also provided.

Helicobacter pylori infection and drugs malabsorption

Drug absorption represents an important factor affecting the efficacy of oral drug treatment. Gastric secretion and motility seem to be critical for drug absorption. A causal relationship between impaired absorption of orally administered drugs and Helicobacter pylori (H. pylori) infection has been proposed. Associations have been reported between poor bioavailability of l-thyroxine and l-dopa and H. pylori infection. According to the Maastricht Florence Consensus Report on the management of H. pylori infection, H. pylori treatment improves the bioavailability of both these drugs, whereas the direct clinical benefits to patients still await to be established. Less strong seems the association between H. pylori infection and other drugs malabsorption, such as delavirdine and ketoconazole. The exact mechanisms forming the basis of the relationship between H. pylori infection and impaired drugs absorption and/or bioavailability are not fully elucidated. H. pylori infection may trigger a chronic inflammation of the gastric mucosa, and impaired gastric acid secretion often follows. The reduction of acid secretion closely relates with the wideness and the severity of the damage and may affect drug absorption. This minireview focuses on the evidence of H. pylori infection associated with impaired drug absorption.

Treatment with thyroid hormone

Thyroid hormone deficiency can have important repercussions. Treatment with thyroid hormone in replacement doses is essential in patients with hypothyroidism. In this review, we critically discuss the thyroid hormone formulations that are available and approaches to correct replacement therapy with thyroid hormone in primary and central hypothyroidism in different periods of life such as pregnancy, birth, infancy, childhood, and adolescence as well as in adult patients, the elderly, and in patients with comorbidities. Despite the frequent and long term use of l-T4, several studies have documented frequent under- and overtreatment during replacement therapy in hypothyroid patients. We assess the factors determining l-T4 requirements (sex, age, gender, menstrual status, body weight, and lean body mass), the major causes of failure to achieve optimal serum TSH levels in undertreated patients (poor patient compliance, timing of l-T4 administration, interferences with absorption, gastrointestinal diseases, and drugs), and the adverse consequences of unintentional TSH suppression in overtreated patients. Opinions differ regarding the treatment of mild thyroid hormone deficiency, and we examine the recent evidence favoring treatment of this condition. New data suggesting that combined therapy with T3 and T4 could be indicated in some patients with hypothyroidism are assessed, and the indications for TSH suppression with l-T4 in patients with euthyroid multinodular goiter and in those with differentiated thyroid cancer are reviewed. Lastly, we address the potential use of thyroid hormones or their analogs in obese patients and in severe cardiac diseases, dyslipidemia, and nonthyroidal illnesses.

Relevance of Liver Failure for Anti-Infective Agents: From Pharmacokinetic Alterations to Dosage Adjustments

The liver is a complex organ with great ability to influence drug pharmacokinetics. Due to its wide array of function, its impairment has the potential to affect bioavailability, enterohepatic circulation, drug distribution, metabolism, clearance, and biliary elimination. These alterations differ widely depending on the cause of the liver failure, if it is acute or chronic in nature, the extent of impairment, and comorbid conditions. In addition, effects on liver functions do not occur in a proportional or predictable manner for escalating degrees of liver impairment. The ability of hepatic alterations to influence PK is also dependent on drug characteristics, such as administration route, chemical properties, protein binding, and extraction ratio, among others. This complexity makes it difficult to predict what these effects have on drugs. Unlike certain classes of agents, efficacy of anti-infectives is most often dependent on fulfilling pharmacokinetic/pharmacodynamic targets, such as C_max/MIC, AUC/MIC, T_>MIC, IC₅₀/EC₅₀, or T>EC₉₅. Loss of efficacy, or conversely, increased risk of toxicity may occur in certain circumstances of liver injury. Although important to consider these potential alterations and their effects on specific anti-infectives, many lack data to constitute specific dosing adjustments, making it important to monitor patients for effectiveness and toxicities of therapy.

Helicobacter pylori infection: selected aspects in clinical management

PURPOSE OF REVIEW

This review focuses on new aspects of recently published guidelines for the management of Helicobacter pylori infection as well as progress in diagnostic tests and treatment regimens. We also discuss new strategies for gastric cancer prevention.

RECENT FINDINGS

The general recommendation to treat H. pylori infection whenever diagnosed still faces resistance for reasons that are pertinent to the diversity of related clinical outcomes and to the complexity of eradication regimens. Thus, new updated guidelines for the management of H. pylori infection have been released in several continents. Progress has been made in molecular diagnostic tests for the detection of antibiotic resistance and serological tests for the detection of advanced gastric atrophic changes. Effective quadruple therapies in various combinations of 'traditional drugs' have been introduced with sequential or concomitant order of administration. Moreover, traditional drugs in a new galenic formulation have been introduced to overcome increasing H. pylori antibiotic resistance. Effective strategies for gastric cancer prevention have been adopted in some countries with high gastric cancer incidence, and have successfully contributed to lower the gastric cancer incidence. A screen-and-treat strategy for individuals at increased risk for gastric cancer needs to be further explored also in areas with low/moderate incidence of gastric cancer.

SUMMARY

New guidelines share many universal similarities across countries but respect and emphasize specific needs and requirements in individual communities. Various combinations of traditional drugs have been successfully introduced to overcome the increasing H. pylori antibiotic resistance. Gastric cancer prevention by a screen and treat strategy showed promising results.

When thyroid hormone replacement is ineffective?

PURPOSE OF REVIEW

In this article, we will consider the failure of thyroid hormone replacement therapy to normalize serum thyroid stimulating hormone concentrations. We will review circumstances and causes for failures, discuss pertinent unpublished personal cases of didactical value, and provide practical suggestions for providers encountering patients with similar presentations.

RECENT FINDINGS

Recent data are available on the benefit of novel formulations of levothyroxine therapy on malabsorption.

SUMMARY

Most frequently, reasons for ineffectiveness are noncompliance, inappropriate administration of levothyroxine, gastrointestinal disorders, and drug interactions. The diagnostic work-up should include careful history to elucidate the potential reasons for the ineffective therapy.

Motor fluctuations and Helicobacter pylori in Parkinson's disease

The presence of Helicobacter pylori (HP) in the gastrointestinal tract may limit the absorption of levodopa. The objectives of this study were to investigate whether HP infection may affect the clinical response to levodopa as well as levodopa dose requirement in patients with Parkinson's disease (PD) as well as to investigate whether HP infection may affect plasma levels of vitamin B12, folic acid, and homocysteine. Seventy-five patients with PD diagnosed at least 4 years ago were included. Symptom fluctuations were assessed by UPDRS-IV and the WOQ9 wearing-off-scale. Plasma levels of vitamin B12, folic acid, and homocysteine were analyzed. Screening for HP was performed with a 13C-labeled urea breath test (Diabact UBT). A propensity-matched analysis was made where each patient in the HP-infected group was matched with one patient in the non-infected group with respect to age and gender. Of the 75 included patients, 20 were HP infected (27 %). Median Hoehn & Yahr scores were 3 in both HP infected patients and the matched group (n = 20). HP-infected patients had decreased "complications of therapy" with average total UPDRS-IV score of 4.8 ± 3.0 vs. 7.7 ± 3.8 (p < 0.05), despite no significant difference in levodopa equivalent dose. Wearing-off and sleep disturbance were significantly less common in the HP group (p < 0.05). There were no differences regarding vitamin B12, folic acid, or homocysteine values. HP infection in patients with PD may result in a decreased occurrence of symptom fluctuations according to this small study. This finding may be due to altered absorption of levodopa in the gastrointestinal tract in patients with HP infection, but further studies are required.

Serum thyrotropin levels following levothyroxine administration at breakfast

BACKGROUND

Hypothyroidism is treated with oral levothyroxine. Some patients fail to attain adequate control because of poor compliance. Delaying breakfast to take levothyroxine on an empty stomach can decrease adherence to hypothyroidism treatment. The objective of this study was to evaluate whether administering levothyroxine with breakfast can maintain thyrotropin (TSH) levels in the therapeutic range, without major clinical changes.

METHODS

A prospective, randomized, open-label, crossover study was conducted to compare usual levothyroxine administration while in a fasting state with administration during breakfast. From September 2008 to April 2009, 45 patients with primary hypothyroidism who received levothyroxine were recruited. The patients completed 180 days of the protocol and were randomized to 90 days of each levothyroxine administration regimen (while fasting or with breakfast). Clinical and biochemical analyses were performed at baseline and on days 45, 90, 135, and 180. The primary outcome was TSH level.

RESULTS

Forty-two patients completed the protocol. The TSH level was higher for levothyroxine administration with breakfast than while fasting (2.89 vs. 1.9 mIU/L, p=0.028). Uncontrolled hypothyroidism (TSH ≥3.5 mIU/L) occurred regardless of the type of levothyroxine administration (p=0.26). No risk factors were identified for TSH elevation.

CONCLUSIONS

Levothyroxine administration with breakfast could be an alternative regimen for patients who have adherence difficulties due to the need for delaying intake, and is more likely to cause variability in the TSH level, meaning the patient should be followed more closely. For patients in whom a specific serum TSH goal is important, taking levothyroxine while fasting is recommended.

Diversity of Bacillus cereus group strains is reflected in their broad range of pathogenicity and diverse ecological lifestyles

Bacillus cereus comprises a highly versatile group of bacteria, which are of particular interest because of their capacity to cause disease. Emetic food poisoning is caused by the toxin cereulide produced during the growth of emetic B. cereus in food, while diarrhoeal food poisoning is the result of enterotoxin production by viable vegetative B. cereus cells in the small intestine, probably in the mucus layer and/or attached to the host's intestinal epithelium. The numbers of B. cereus causing disease are highly variable, depending on diverse factors linked to the host (age, diet, physiology and immunology), bacteria (cellular form, toxin genes and expression) and food (nutritional composition and meal characteristics). Bacillus cereus group strains show impressive ecological diversity, ranging from their saprophytic life cycle in soil to symbiotic (commensal and mutualistic) lifestyles near plant roots and in guts of insects and mammals to various pathogenic ones in diverse insect and mammalian hosts. During all these different ecological lifestyles, their toxins play important roles ranging from providing competitive advantages within microbial communities to inhibition of specific pathogenic organisms for their host and accomplishment of infections by damaging their host's tissues.

Possible benefit from treatment of Helicobacter pylori in antihistamine-resistant chronic urticaria

BACKGROUND

Some patients with chronic spontaneous urticaria (CU) are resistant to conventional doses of antihistamine (AH) medications. Some research groups have reported an association between CU and Helicobacter pylori infection.

AIM

To determine whether H. pylori eradication can reverse AH resistance in CU.

METHODS

We retrospectively reviewed cases of patients with CU, and recorded their Urticaria Activity Score (UAS) and results of a (13)C-urea breath test ((13)C-UBT) for H. pylori infection. Patients without improvement in CU despite a full 8 weeks of AH treatment at four times the initial dose comprised the resistant CU group, while the patients who did respond comprised the responsive CU group. Patients with resistant CU and a positive (13)C-UBT (n = 46) were offered a 14-day treatment with amoxicillin 1 g twice daily, clarithromycin 500 mg twice daily and omeprazole 20 mg twice daily. The effect of H. pylori eradication on CU was evaluated by the UAS, measured at baseline and at 8, 16, and 28 weeks after triple therapy.

RESULTS

Of the 46 patients with resistant CU, 29 (63%) had a positive (13)C-UBT result. Treatment eradicated H. pylori in 18 of the 29 patients (subgroup A), and 11 patients refused the triple therapy (subgroup B). The remaining 17 patients had a negative (13)C-UBT result, (subgroup C). In subgroup A, baseline UAS reduced from 5.29 ± 0.94 to 3.62 ± 0.96 (P = 0.03) at week 8; to 1.43 ± 0.41 (P < 0.001) at week 16, and to 1.17 ± 0.32 (P = 0.04) at week 28. Five of the patients (27.8%) in this group were completely free of symptoms at week 28, whereas none of the untreated patients achieved complete remission.

CONCLUSION

Some patients with resistant CU might benefit from H. pylori eradication.

Survival of Bacillus cereus vegetative cells and spores during in vitro simulation of gastric passage

The enteric pathogen Bacillus cereus must survive gastric passage in order to cause diarrhea by enterotoxin production in the small intestine. The acid resistance and the survival after gastric passage were assessed by in vitro experiments with acidified growth medium and gastric simulation medium with B. cereus NVH 1230-88 vegetative cells and spores. First, batch incubations at constant pH values for 4 h, which represented different physiological states of the stomach, showed that spores were resistant to any gastric condition in the pH range of 2.0 to 5.0, while vegetative cells were rapidly inactivated at pH values of ≤4.0. Second, a dynamic in vitro gastric experiment was conducted that simulated the continuously changing in vivo conditions due to digestion dynamics by gradually decreasing the pH from 5.0 to 2.0 and fractional emptying of the stomach 30 to 180 min from the start of the experiment. All of the B. cereus spores and 14% (± 9%) of the vegetative cells survived the dynamic simulation of gastric passage.

IRAK-M modulates expression of IL-10 and cell surface markers CD80 and MHC II after bacterial re-stimulation of tolerized dendritic cells

BACKGROUND

As essential components of the innate immune system, dendritic cells (DCs) can interact directly with pathogens as well as participate in the adaptive immune response. In cells closely related to DCs such as macrophages and monocytes, prior exposure to minute amounts of endotoxin can lead to a refractory period where subsequent exposure to higher doses fails to induce an inflammatory response; little research has investigated this effect on DCs. This study tested if murine bone marrow-derived dendritic cells (BM-DCs) respond to endotoxin- and bacterial sonicate-induced tolerance by decreased inflammatory and increased anti-inflammatory response, and the role of IRAK-M, an intracellular negative regulator of TLR signaling, in this tolerance.

RESULTS

Tolerized BM-DCs exhibited a significant drop in TNF-α and IL-12p70 production and increased IL-10 expression compared to untolerized cells. BM-DCs also showed the ability to develop heterotolerance, in which the LPS exposure alone was able to induce tolerance to Helicobacter pylori sonicate and TLR2 agonist Pam3Cys. Furthermore, the expression of IRAK-M was increased after restimulation of tolerized BM-DCs as determined qPCR and Western blot. IRAK-M exhibited a suppressive effect on surface expression of major histocompatibilty complex class II (MHC II) and CD80 in LPS-tolerized BM-DCs. IL-10 expression in bacterial sonicate-tolerized IRAK-M-/- BM-DCs was altered as compared to wild type BM-DCs, with tolerance-induced expression of IL-10 mitigated in tolerized IRAK-M-/- BM-DCs.

CONCLUSION

Along with endotoxin, bacterial sonicate is able to induce refractory tolerance in BM-DCs, and IRAK-M plays a role in modulating cell surface expression of MHC class II and CD80 and release of IL-10 during this tolerance.

Helicobacter pylori eradication for Parkinson's disease

BACKGROUND

Levodopa is the mainstay of treatment for alleviating the motor symptoms associated with Parkinson's disease. However, patients often experience fluctuations in their symptoms over time and 'wearing off' which may be partly related to variable absorption of the drug. There is some evidence that treatment of the common gastrointestinal infection Helicobacter pylori (H pylori) with antibiotics may improve levodopa absorption in the gut and hence improve symptoms.

OBJECTIVES

1) What is the prevalence of H pylori in Parkinson's disease patients? 2) Does treatment of H pylori infection with antibiotics improve symptoms in Parkinson's disease patients? Is this effect dependent on improvements in the absorption of levodopa?

SEARCH METHODS

We searched electronic databases (including CENTRAL, MEDLINE, EMBASE, PsycINFO and CINAHL) and trial registers, handsearched conference proceedings and carried out citation searching on key articles. All searching was updated in August 2009. We contacted authors to provide additional information where necessary.

SELECTION CRITERIA

Clinical trials in patients with a well-defined definition of Parkinson's disease and who were H pylori-positive. Two people independently selected studies for inclusion using predetermined criteria. We used recruitment figures from clinical trials and other studies identified from the searching to determine the prevalence of H pylori in Parkinson's disease.

DATA COLLECTION AND ANALYSIS

Two authors abstracted data from the source papers and assessed methodological quality independently. We presented results descriptively.

MAIN RESULTS

Two completed and one ongoing clinical trial met the inclusion criteria. One trial (34 patients randomised) examined the effects of H pylori eradication on levodopa absorption and motor symptoms and found significant improvements in both. The ongoing trial has similar objectives and aims to recruit 100 patients. The other completed trial (20 patients analysed) sought to find a causal link between infection with H pylori and Parkinsonism and was non-contributory. A worsening of symptoms was noted with eradication failure.The prevalence of H pylori in Parkinson's disease was reported in four studies and ranged from 37% to 59% which is similar to that of the general population.

AUTHORS' CONCLUSIONS

There is currently a lack of evidence on the effects of screening and treating H pylori in patients with Parkinson's disease. There is limited evidence to suggest that H Pylori eradication improves the absorption of levodopa and improves motor symptoms. Results from an ongoing trial will inform the evidence base and will be incorporated in an update of this review. There is a need for well-conducted randomised controlled trials with standard outcome measures for motor symptoms and incorporating the costs of screening and treatment.

The difficult patient: drug interaction and the influence of concomitant diseases on the treatment of hypothyroidism

Although most hypothyroid patients do well with one single tablet of thyroxine daily, approximately 10% are dissatisfied and another important group of patients is difficult to control. We reviewed the most common causes for frequent-dose adjustment or high-dose requirement, including poor compliance with therapy and inadequate medication. Since these two causes have been ruled out, drug interaction and other concomitant diseases need to be investigated. Requirements of thyroxine increase in all conditions characterized by impaired gastric acid secretion. Proton-pump inhibitors, antacids and a long list of drugs may decrease thyroxine absorption. In addition, a series of diseases including celiac disease and chronic inflammatory intestinal diseases, as well as nutritional habits may be important in patient control. Finally, we mention the effects of a growing list of drugs and thyroid disruptors that may also affect thyroid hormone metabolism at many levels.

The role of Helicobacter pylori in patients with hypothyroidism in whom could not be achieved normal thyrotropin levels despite treatment with high doses of thyroxine

BACKGROUND

 Helicobacter pylori infection is a most frequent cause of chronic gastritis. H. pylori may decrease absorption of oral thyroxine by decreasing gastric acid secretion in the stomach. In this study, we aimed to investigate the change in thyroid function tests of the cases after H. pylori eradication who were not responding to high doses of thyroxine treatment before H. pylori eradication.

METHODS

 Hypothyroid cases who were not responding to high doses of thyroxine among the ones presented to Endocrinology and Gastroenterohepatology Clinics of Sisli Etfal Training and Research Hospital between 2009 and 2010 were included in the study. Thyroid function tests were performed two times in all cases before and after H. pylori eradication. Duodenal, antral and corporal biopsies, and jejunal aspirates and biopsies were taken during upper gastrointestinal system endoscopies performed in all patients. Cases without intestinal pathology were included in the study.

RESULTS

Serum thyrotropin (TSH), free T3, and free T4 values before H. pylori eradication were 30.5 ± 28.8 IU/mL, 2.64 ± 0.56 pg/mL, and 0.92 ± 0.32 ng/mL, respectively, and after eradication were found to be 4.2 ± 10.6 IU/mL, 3.02 ± 0.61 pg/mL, and 1.3 ± 0.34 ng/mL, respectively (p values <.001, .002, and <.001, respectively). After H. pylori eradication treatment, TSH decreased in all of the cases, factitious thyrotoxicosis developed in % 21 of these cases.

CONCLUSION

In hypothyroid cases, H. pylori gastritis may be responsible for an inadequate response to the treatment. H. pylori eradication in the cases receiving high doses of thyroxine has a risk for thyrotoxicosis.

Differential effect of Helicobacter pylori eradication on time-trends in brady/hypokinesia and rigidity in idiopathic parkinsonism

BACKGROUND

We examine the effect of eradicating Helicobacter in idiopathic parkinsonism (IP). Marked deterioration, where eradication-therapy failed, prompted an interim report in the first 20 probands to reach de-blinding. The null-hypothesis, "eradication has no effect on principal outcome, mean stride length at free-walking speed," was rejected. We report on study completion in all 30 who had commenced post-treatment assessments.

METHODS

This is a randomized, placebo-controlled, parallel-group efficacy study of eradicating biopsy-proven (culture and/or organism on histopathology) Helicobacter pylori infection on the time course of facets of IP, in probands taking no, or stable long-t(1/2), anti-parkinsonian medication. Persistent infection at de-blinding (scheduled 1-year post-treatment) led to open active eradication-treatment.

RESULTS

Stride length improved (73 (95% CI 14-131) mm/year, p = .01) in favor of "successful" blinded active over placebo, irrespective of anti-parkinsonian medication, and despite worsening upper limb flexor rigidity (237 (57-416) Nm x 10(-3)/year, p = .01). This differential effect was echoed following open active, post-placebo. Gait did not deteriorate in year 2 and 3 post-eradication. Anti-nuclear antibody was present in all four proven (two by molecular microbiology only) eradication failures. In the remainder, it marked poorer response during the year after eradication therapy, possibly indicating residual "low-density" infection. We illustrate the importance of eradicating low-density infection, detected only by molecular microbiology, in a proband not receiving anti-parkinsonian medication. Stride length improved (424 (379-468) mm for 15 months post-eradication, p = .001), correction of deficit continuing to 3.4 years. Flexor rigidity increased before hydrogen-breath-test positivity for small intestinal bacterial overgrowth (208 (28-388) Nm x 10(-3), p = .02), increased further during (171 (67-274), p = .001) (15-31 months), and decreased (136 (6-267), p = .04) after restoration of negativity (32-41 months).

CONCLUSION

Helicobacter is an arbiter of progression, independent of infection-load.

Systematic review: impaired drug absorption related to the co-administration of antisecretory therapy

BACKGROUND

Due to suppression of gastric acidity during antisecretory therapy, an impaired absorption of co-administered drugs may occur.

AIM

To review evidence of impaired drug absorption related to the use of co-administered PPIs or H2RAs.

METHODS

Systematic search of MEDLINE/EMBASE/SCOPUS databases (1980-September 2008) for English articles with keywords: drug malabsorption and absorption, stomach, anti-secretory/acid inhibitory drugs, histamine H2 antagonists, PPIs, gastric acid, pH, hypochlorhydria, gastric hypoacidity. From 2126 retrieved articles, 16 randomized crossover studies were identified investigating impaired absorption of nine different drugs in association with co-administration of PPIs or H2RAs. Information on investigated drug, study type, features of investigated subjects, study design, type of intervention, and study results were extracted.

RESULTS

The identified studies investigated the absorption kinetics of nine drugs. Acid suppression reduced absorption of ketoconazole, itraconazole, atazanavir, cefpodoxime, enoxacin and dipyridamole (median C(max) reduction by 66.5%). An increased absorption of nifedipine and digoxin (median AUC increase by 10%) and a 2-fold-increase in alendronate bioavailability were observed.

CONCLUSIONS

Gastric pH appears relevant for absorption of some cardiovascular or infectious disease agents. Antisecretory treatment may significantly modify the absorption of co-administered drugs.