Measuring adherence to antiretroviral medications in clinical trials

Antiretroviral medications have the potential to transform HIV infection from a fatal to a chronic disease. One of the significant barriers to clinical success is medication nonadherence. Measuring adherence in clinical trials is increasingly important because inadequate adherence may explain some of the variation in clinical response in antiretroviral clinical trials. Additionally, to quantitate the success of interventions that improve adherence, accurate measures need to be utilized. This article summarizes commonly used adherence measures in HIV clinical trials and observational studies such as patient self-report, pill counts, plasma levels, and electronic monitoring. The merits and shortcomings of each measure are discussed.

Adherence to combination antiretroviral therapy: synthesis of the literature and clinical implications

Adherence to combination antiretroviral therapy has a strong impact on virologic response and emergence of viral resistance. However, monitoring adherence in the clinic is difficult. What a patient says or a clinician believes about a patient's adherence may be misleading. Patients with suboptimal adherence may have reduced or undetectable viral loads. On the other hand, viral load may not decrease in patients with perfect adherence because of pretreatment resistance, poor drug metabolism, or other factors. A multidisciplinary approach involving patients, health care professionals, family, and friends may optimize adherence. This article reviews the literature on adherence to antiretroviral therapy, critiques the various adherence measures used by researchers and clinicians, and discusses the clinical implications of adherence to antiretroviral therapy.

A population-based survey of tuberculosis symptoms: how atypical are atypical presentations?

There is scant information on tuberculosis symptoms from a population-based perspective. We prospectively identified 526 tuberculosis cases reported in Los Angeles County over a 6-month period. Of 313 persons who completed our questionnaire, 72.7% had cough, 48.2% for >2 weeks, and 52.3% had fever, 29.4% for >2 weeks. Among those with pulmonary disease, only 52.4% had cough for >2 weeks. In a multivariate model, persons with significant symptoms typical of tuberculosis disease (defined as cough or fever for >2 weeks, weight loss, or hemoptysis) were associated with lack of medical insurance, negative tuberculin skin test, diagnosis during a process other than screening, and non-Asian race. In summary, classic symptoms of prolonged cough and fever are insensitive predictors of tuberculosis. Our data suggest that Asians may need to be added to the list of persons who present with tuberculosis atypically. We believe that the Infectious Diseases Society of America guidelines for community-acquired pneumonia should emphasize demographic features in addition to clinical symptoms when suggesting which patients require evaluation for Mycobacterium tuberculosis.

High-risk sexual behavior in Los Angeles: who receives testing for HIV?

No recent population-based data on HIV testing in people with high-risk sexual behavior are available. We sought predictors of testing using data from the 1997 Los Angeles County Health Survey, a random-digit telephone survey of 8004 county households. An estimated 2.3 million (35.5%) adults were tested for HIV in the past 2 years and approximately 370,000 (5.6%) engaged in high-risk sexual behavior (defined as having > or =2 partners in the past 12 months and not always using condoms). Among high-risk persons, an estimated 46% of heterosexual men, 56% of heterosexual women, and 72% of men who had sex with men (MSM) were tested for HIV. In a multivariable model of high-risk people, both heterosexual men (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.16-0.61) and women (OR, 0.41; 95% CI, 0.19-0.87) had significantly lower proportions of testing than MSM. Although African Americans and Hispanics had significantly higher testing proportions than whites overall among all county residents, those reporting high-risk sexual behavior did not test at higher proportions. We conclude that the proportion of adults with high-risk sexual behavior tested for HIV is higher than almost a decade ago. However, testing among this group remains suboptimal. Future public health campaigns should intensify efforts to encourage HIV testing among this population.

Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions

Herbal medicinals are being used by an increasing number of patients who typically do not advise their clinicians of concomitant use. Known or potential drug-herb interactions exist and should be screened for. If used beyond 8 weeks, Echinacea could cause hepatotoxicity and therefore should not be used with other known hepatoxic drugs, such as anabolic steroids, amiodarone, methotrexate, and ketoconazole. However, Echinacea lacks the 1,2 saturated necrine ring associated with hepatoxicity of pyrrolizidine alkaloids. Nonsteroidal anti-inflammatory drugs may negate the usefulness of feverfew in the treatment of migraine headaches. Feverfew, garlic, Ginkgo, ginger, and ginseng may alter bleeding time and should not be used concomitantly with warfarin sodium. Additionally, ginseng may cause headache, tremulousness, and manic episodes in patients treated with phenelzine sulfate. Ginseng should also not be used with estrogens or corticosteroids because of possible additive effects. Since the mechanism of action of St John wort is uncertain, concomitant use with monoamine oxidase inhibitors and selective serotonin reuptake inhibitors is ill advised. Valerian should not be used concomitantly with barbiturates because excessive sedation may occur. Kyushin, licorice, plantain, uzara root, hawthorn, and ginseng may interfere with either digoxin pharmacodynamically or with digoxin monitoring. Evening primrose oil and borage should not be used with anticonvulsants because they may lower the seizure threshold. Shankapulshpi, an Ayurvedic preparation, may decrease phenytoin levels as well as diminish drug efficacy. Kava when used with alprazolam has resulted in coma. Immunostimulants (eg, Echinacea and zinc) should not be given with immunosuppressants (eg, corticosteroids and cyclosporine). Tannic acids present in some herbs (eg, St John wort and saw palmetto) may inhibit the absorption of iron. Kelp as a source of iodine may interfere with thyroid replacement therapies. Licorice can offset the pharmacological effect of spironolactone. Numerous herbs (eg, karela and ginseng) may affect blood glucose levels and should not be used in patients with diabetes mellitus.

Staphylococcus aureus meningitis in a patient with acquired immunodeficiency syndrome

Meningitis due to Staphylococcus aureus is well described but uncommon. Most cases arise as a complication of neurosurgical interventions or head trauma, although some arise spontaneously. To our knowledge, no case of S. aureus meningitis has been previously reported in a person with the acquired immunodeficiency syndrome (AIDS). Herein we describe a case of S. aureus meningitis in a person with AIDS who had no history of a neurosurgical procedure, head trauma, or overwhelming bacteremia. Treatment of this infection was successful. S. aureus should be added to the list of potential pathogens that can cause spontaneous meningitis in people with AIDS.

Bacterial oxidation of methyl bromide in fumigated agricultural soils

The oxidation of [(sup14)C]methyl bromide ([(sup14)C]MeBr) to (sup14)CO(inf2) was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl(inf3)NO(inf2)). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [(sup14)C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to (sup14)CO(inf2) and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy.

The NMDA receptor competitive antagonist CPP modulates benzodiazepine tolerance and discontinuation

Benzodiazepine discontinuation is characterized by a syndrome of increased activity and reduced seizure threshold that is similar to effects mediated by the glutamatergic system. To elucidate the involvement of the glutamatergic system in benzodiazepine tolerance and discontinuation, we administered lorazepam, the NMDA antagonist CPP, and the combination of these compounds either concomitantly or consecutively to mice via osmotic pumps and evaluated pentylenetetrazole-induced seizure threshold, open-field activity, and benzodiazepine receptor binding during and after chronic administration. Animals receiving lorazepam alone developed partial tolerance at 7 days and complete tolerance at 14 days to the anticonvulsant effects of lorazepam. This effect was partly attenuated by CPP coadministration with lorazepam. This combination produced only partial tolerance. A reduction in seizure threshold was observed 4 days after discontinuation of lorazepam alone. This effect was abolished by coadministration of CPP with lorazepam and by CPP administration during the withdrawal period. Benzodiazepine binding in most structures examined was significantly reduced at 14 days during chronic lorazepam administration (versus 1 day), and coadministration of CPP did not alter this decrement. After lorazepam discontinuation, binding was increased at 4 and 7 days versus chronically treated animals and versus vehicle within the cerebral cortex. This effect was abolished by coadministration of CPP as well as by CPP administration during the lorazepam withdrawal period. These data support the involvement of the glutamatergic system in benzodiazepine tolerance and discontinuation.

Use of patient education and monitoring software in community pharmacies

OBJECTIVE

To determine the level of use of health education and monitoring software programs in independent community pharmacies in rural locales.

DESIGN

The use of seven software programs that deliver patient education and provide blood pressure monitoring was assessed at five sites of the Nebraska Drug Information Network (NDIN) for one month. Direct Access, a Windows-based software program, documented which programs were accessed and for what time period.

RESULTS

During a one-month period, 326 accesses were logged representing 44 hours of computer time. Extrapolated to all 30 sites of NDIN, this represents 264 hours and 1,956 accesses monthly. On average, each pharmacy logged 8.8 hours within 65 accesses each month. Each access averaged 8 minutes. DynaPulse (167 accesses; 16.4 hours) was the most frequently used product, followed by Home Medical Advisor Pro (54 accesses; 8.9 hours) and Mayo Clinic The Family Pharmacist (35 accesses; 8.3 hours). The least amount of time was spent with BodyWorks (0.6 hours) but Wellness Checkpoint had fewest accesses (7 accesses).

CONCLUSION

Applied medical informatics is assuming a larger role in daily clinical practice as pharmacy practitioners strive to better inform their patients. This is congruent with the finding that a better informed public can be a healthier public. This study demonstrates that computer systems are readily used by patients and pharmacists in rural communities.

Meningitis in older patients: how to diagnose and treat a deadly infection

Studies of bacterial meningitis have documented a peak of incidence among persons age 60 and older. The most common bacterial pathogens in these patients differ from those seen in children. Presentation of meningitis in older patients may be atypical; fever is not a consistent finding, and nonspecific symptoms such as confusion are often seen. Nuchal rigidity is not as sensitive nor as specific a sign as in younger patients. Definitive diagnosis relies on interpretation of CSF studies. Ampicillin plus a third-generation cephalosporin should be administered for community-acquired meningitis until Gram's stain and culture results return. Cases of S pneumoniae meningitis may require varying strategies, based upon the degree of penicillin resistance.

Sustained release of acetaminophen from heterogeneous matrix tablets: influence of polymer ratio, polymer loading, and co-active on drug release

The aim of this research was to investigate the effect of pseudoephedrine (PE), polymer ratio, and polymer loading on the release of acetaminophen (APAP) from hydroxypropyl methyl cellulose (HPMC)/polyvinylpyrrolidone (PVP) matrices. Granules formulated with APAP or both APAP and PE, and various blends of HPMC and PVP were compressed into tablets at varying compression forces ranging from 2000 to 6000 Ib. In vitro drug release from the matrix tablets was determined and the results correlated with those of tablet water uptake and erosion studies. Drug release from the formulations containing both APAP and PE was slower than those containing only APAP (P < 0.05, F = 3.10). Drug release from tablets formulated with APAP only showed an initial burst at pH 1.16 or 7.45, and at high total polymer loading (> or = 9.6%). Formulations containing both APAP and PE showed slower drug release at pH 1.16 than at pH 7.45. At pH 1.16, a decline in the percentage of APAP released occurred after 18 hours. This was due to the hydrolysis of APAP to p-aminophenol. The drug dissolution data showed good fit to the Korsmeyer and Peppas model, and the values of the release exponents ranged from 0.20 to 0.62, indicating a complex drug release pattern. Tablet erosion studies indicated that the amount of APAP released was linearly related to the percentage of tablet weight loss. The kinetics of tablet water uptake was consistent with a diffusion and stress relaxation controlled mechanism. Overall, the results of this study indicated that PE, as a co-active in the formulation, modified the matrix, and hence retarded APAP release.

Pulsed-field gel electrophoresis and ribotype profiles of clinical and environmental Vibrio vulnificus isolates

Vibrio vulnificus belongs to the autochthonous bacterial flora of warm estuarine waters. It can cause life-threatening extraintestinal disease in persons who have underlying illness and who consume raw shellfish or contact wounds with estuarine water. Currently, very little is known about genetic diversity within this species. In this report, we describe high-level variation in restriction fragment length polymorphism profiles among 53 clinical and 78 environmental isolates, as determined by pulsed-field gel electrophoresis. In contrast, ribotype profiles showed greater similarity. When combined ribotype profiles of clinical and environmental isolates were analyzed, four predominant clusters were observed. Interestingly, a low number (16%) of clinical isolates were found in cluster C, compared with clusters A, B, and D (range, 50 to 83%). In addition, 83% of all Hawaiian isolates were located in a single cluster, indicating a possible relationship between geography and genotype. We also report that spontaneous translucent colonial morphotypes were distinct by both restriction fragment length polymorphism and biochemical profiles, compared with opaque parent strains.

Provider profiling: advancing to episodes of care

Judging by the interest expressed by managed care organizations, provider profiling has arrived. Surveys indicate that most organizations have adopted, or plan to adopt in the near future, a means to describe provider practice patterns. A further vote of confidence came from providers: In 1994, the American College of Physicians, the largest national specialty organization, issued a position paper supporting provider profiling and questioning the value of other approaches to utilization management, such as preauthorization of individual services. Also, an article and an editorial in the New England Journal of Medicine cautiously supported the concept of profiling. Provider profiling has great promise as a means to promote cost-effective care without the limitations of case-by-case preauthorization. The combination of a sophisticated episode of care methodology and a set of validated practice benchmarks offers the opportunity to perform true clinical profiling and to supply providers with data to review and alter practice patterns.

Prenatal lorazepam exposure: 4. Persistent alterations in pentylenetetrazole-induced seizure threshold and GABA-dependent chloride uptake after prenatal lorazepam exposure

Prenatal benzodiazepine exposure is associated with behavioral and neurochemical alterations in the early postnatal period. To determine the persistence of these effects, we evaluated pentylenetetrazole-induced seizure threshold and GABA-dependent chloride uptake in mice at 6 and 12 months of age after prenatal lorazepam exposure. Seizure threshhold was reduced after acute lorazepam pretreatment in mice exposed to lorazepam prenatally, compared to control groups, at 6 and 12 months of age. Maximal GABA-dependent chloride uptake was also reduced in exposed mice at 6 and 12 months of age. These data indicate that behavioral and neurochemical alterations persist well into maturity after prenatal lorazepam exposure.

Methylmercury oxidative degradation potentials in contaminated and pristine sediments of the carson river, nevada

Sediments from mercury-contaminated and uncontaminated reaches of the Carson River, Nevada, were assayed for sulfate reduction, methanogenesis, denitrification, and monomethylmercury (MeHg) degradation. Demethylation of [(sup14)C]MeHg was detected at all sites as indicated by the formation of (sup14)CO(inf2) and (sup14)CH(inf4). Oxidative demethylation was indicated by the formation of (sup14)CO(inf2) and was present at significant levels in all samples. Oxidized/reduced demethylation product ratios (i.e., (sup14)CO(inf2)/(sup14)CH(inf4) ratios) generally ranged from 4.0 in surface layers to as low as 0.5 at depth. Production of (sup14)CO(inf2) was most pronounced at sediment surfaces which were zones of active denitrification and sulfate reduction but was also significant within zones of methanogenesis. In a core taken from an uncontaminated site having a high proportion of oxidized, coarse-grain sediments, sulfate reduction and methanogenic activity levels were very low and (sup14)CO(inf2) accounted for 98% of the product formed from [(sup14)C]MeHg. There was no apparent relationship between the degree of mercury contamination of the sediments and the occurrence of oxidative demethylation. However, sediments from Fort Churchill, the most contaminated site, were most active in terms of demethylation potentials. Inhibition of sulfate reduction with molybdate resulted in significantly depressed oxidized/reduced demethylation product ratios, but overall demethylation rates of inhibited and uninhibited samples were comparable. Addition of sulfate to sediment slurries stimulated production of (sup14)CO(inf2) from [(sup14)C]MeHg, while 2-bromoethanesulfonic acid blocked production of (sup14)CH(inf4). These results reveal the importance of sulfate-reducing and methanogenic bacteria in oxidative demethylation of MeHg in anoxic environments.

A comparative evaluation of oral contraceptive use and associated compliance issues in a rural population

One hundred thirty-three patients were enrolled in a study designed to evaluate and compare oral contraceptive use in three rural communities. The patients averaged 31 years old (range, 13 to 49 years); 92% were white, 4.5% Hispanic, and 3% Native American. Genora, Ortho-Novum, and Triphasil were the most frequently prescribed oral contraceptives. Triphasic oral contraceptives accounted for one third (n = 64) of 203 prescriptions, and conventional monophasic preparations accounted for two thirds. Twenty percent (n = 26) of the patients studied were non-compliant. The most frequent causes of noncompliance cited were cost and inconvenience. However, generic alternatives were requested in only 43% of the cases for which generic equivalents were available. Less-expensive alternatives (eg, generic products, medroxyprogesterone acetate injection) should be advocated to deter patient noncompliance because of cost issues. Drug interactions and adverse effects were not reported in our patient population and thus did not contribute to noncompliance.

Pregnenolone sulfate potentiation of NMDA-mediated increases in intracellular calcium in cultured chick cortical neurons

Pregnenolone sulfate (PS) has been reported to selectively augment glutamate-induced depolarizations mediated by the NMDA subtype of the glutamate receptor. The present study examines the ability of this neuroactive steroid to potentiate NMDA-mediated increases in intracellular calcium in cultured chick cortical neurons using the fluorescent dye Fura2. PS, in the absence of NMDA and glycine, significantly elevated intracellular calcium at 250 and 500 microM. This increase in free calcium was significantly attenuated at 250 microM PS by the prior addition of 50 microM CNQX, 10 microM dizocilpine or 1 microM nimodipine. NMDA and glycine, when added to the cells in saturating concentrations of 500 and 50 microM, respectively, consistently increased intracellular free calcium over baseline levels. In the presence of NMDA and glycine, both 50 and 100 microM PS produced a further significant rise in intracellular free calcium. The prior addition of CNQX, dizocilpine or both compounds together significantly inhibited this elevation in free calcium. The application of the endogenous polyamine spermine (250 microM) significantly potentiated the response of chick cortical neuronal cells to NMDA and glycine. PS, in the presence of NMDA, glycine and spermine, produced a further increase in intracellular free calcium at concentrations of 50 and 100 microM. The prior application of CNQX, dizocilpine or both compounds together significantly attenuated this rise in free calcium. These data confirm that PS is a positive allosteric modulator of the NMDA receptor and provide evidence that this neurosteroid does not interact with the polyamine modulatory site.