OTC NICOTINE REPLACEMENT AS EFFECTIVE AS PRESCRIPTION

A recent meta-analysis by Hughes et al has shown that switching nicotine replacement therapy (NRT) from prescription to over-the-counter products has not changed their efficacy.

The analysis included five controlled trials of over-the-counter NRT versus placebo and four trials of over-the-counter NRT versus prescription NRT. The main findings were that NRT is pharmacologically effective in a nonprescription setting and that it produces quit rates similar to those achieved with prescription NRT.

The authors noted that most of the trials included in their analysis used the nicotine patch; only one studied nicotine gum, and none used the nicotine inhaler or tablet. This may have affected the results because unlike the patch, the gum and the inhaler require repeated self administration to be effective. Thus, in a nonprescription setting, low motivation and less instruction on use could result in poor compliance. On the other hand, survey studies indicated that compliance with nicotine gum appears to be similar to that seen with the patch.

The 7% long-term quit rate reported in this meta-analysis was similar in both over-the-counter and prescription settings. Nevertheless, switching its status from prescription to over-the-counter has increased the NRT use and quit attempts.

Hughes JR, Shiffman S, Callas P, Zhang J. A meta-analysis of the efficacy of over-the-counter nicotine replacement. Tobacco Control. 2003;12:21-27.

COMMUNICATION KEY TO ASTHMA MANAGEMENT IN CHILDREN

Compliance with asthma medication among inner-city children is hindered by the lack of communication between caregivers and physicians, a study by Riekert et al reported.

The study enrolled 318 inner-city children ages 5 to 12 with physician-diagnosed asthma who had had asthma symptoms at least twice in the previous two weeks. Caregivers answered a survey regarding demographic information, the child’s current asthma symptoms and health care use, and their beliefs about asthma management. Physicians were asked to give the name, dosage, and frequency of all asthma medications prescribed for each patient.

Sixty-four percent of the children met the criteria for moderate to severe asthma. Despite this, the frequency with which asthma controller medications were prescribed was low. Physicians reported that they had prescribed controllers for 42% of the children, and only 32% of the caregivers reported having received such a prescription.

In almost one third of the cases in which caregivers said that they had received a controller prescription, the physicians reported that they had not written such a prescription. Overall, physicians and caregivers disagreed about whether a controller prescription had been written in 69 (22%) of the cases.

When caregivers and physicians agreed about whether a controller prescription had been written, caregivers tended to have positive attitudes towards asthma management and the children were highly likely to receive their medications properly. Caregivers who disagreed with physicians about whether controller medications had been prescribed tended to have poor attitudes about asthma management; they often did not understand the need for daily medication and were more likely to be concerned about side effects.

The authors suggested that physicians must learn to communicate more effectively with the caregivers of inner-city children with asthma. By addressing caregivers’ concerns, physicians can improve health outcomes and patient satisfaction.

Riekert KA, Butz AM, Eggleston PA, et al. Caregiver-physician medication concordance and undertreatment of asthma among inner-city children. Pediatrics. 2003;111:e214-e220.

IFN-GAMMA CONCENTRATIONS AS MARKER FOR TUBERCULOUS PLEURAL EFFUSION

Among four biological markers for tuberculous pleuritis, the most sensitive and specific is interferon gamma (IFN-gamma).

Aoe et al studied 46 patients with pleural effusion. They measured concentrations of IFN-gamma, adenosine deaminase (ADA), immunosuppressive acidic protein (IAP), and soluble interleukin-2 receptors (sIL-2Rs) to determine their diagnostic sensitivity.

For each patient, at least 40 mL of pleural fluid was drawn during thoracentesis. Patients with tuberculosis had higher levels of ADA, IFN-gamma, IAP, and sIL-2Rs than did patients without tuberculosis. To determine sensitivity and specificity, receiver operating characteristic analysis was performed. IFN-gamma was clearly the best diagnostic indicator for tuberculous pleuritis.

Conventional diagnostic methods are not sufficient, said the authors. Direct examination of pleural fluid requires bacillar densities of 10,000/mL and has low sensitivity. Culturing pleural fluid is more sensitive, but Mycobacterium tuberculosis takes two to six weeks to grow. Pleural biopsy has a greater sensitivity than thoracentesis, but it requires technical expertise, is invasive, and is subject to sampling error.

The authors noted that an assay for IFN-gamma could be an important screening tool for patients who have suspected tuberculous pleuritis. They added that although measuring IFN-gamma levels is relatively expensive, determining those levels at the onset of pleural effusion could help clinicians start treatment sooner than if other, less expensive methods were used.

Aoe K, Hiraki A, Murakami T, et al. Diagnostic significance of interferon-gamma in tuberculous pleural effusions. Chest. 2003;123:740-744.

INFANT IGE LEVELS PREDICT LATER ASTHMA

In wheezing infants, levels of specific immunoglobulin E (IgE) to wheat, egg white, or inhaled allergens can predict the onset of asthma in later childhood.

Kotaniemi-Syrjänen et al conducted a prospective follow-up study in 80 children who were hospitalized for wheezing in 1992 and 1993, when the children were between the ages of 1 and 23 months. Total IgE and eosinophil cationic protein (ECP) concentrations were determined. Serum samples were obtained and frozen.

The children were reevaluated in 1999. Questionnaires were used to gauge asthma symptoms, and a diagnosis of allergic rhinitis or atopic dermatitis was recorded. Exercise challenge tests were performed and pulmonary function was measured. In 2000, the original frozen serum samples were tested for allergen-specific IgE antibodies.

At follow-up, 32 children were asthmatic. An elevated level (0.35 kU/L or higher) of specific IgE to wheat, egg white, or a mixture of inhaled allergens was significantly associated with the development of asthma. There were also significant associations between total serum IgE levels, elevated serum ECP concentrations, blood eosinophilia, and atopic dermatitis.

The authors concluded that the presence of allergen-specific IgE antibodies in infants can be used to predict the later development of atopy and, if wheezing is present, atopic asthma.

Kotaniemi-Syrjänen A, Reijonen TM, Romppanen J, et al. Allergen-specific immunoglobulin E antibodies in wheezing infants: the risk for asthma in later childhood. Pediatrics. 2003;111:e255-e261.

BLOOD GLUCOSE AFFECTS LUNG FUNCTION IN SMOKERS

Lower levels of pulmonary function have been associated with both high fasting blood glucose levels and a diagnosis of diabetes. According to a recent study, the association was strongest among smokers.

Walter et al used data from members of the Offspring Cohort of the Framingham Heart Study. The primary variables examined were fasting blood glucose levels, smoking status, and spirometric data. Of the 3,254 subjects, 280 had diabetes.

Among current smokers, both mean residual forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were lower in diabetic patients than in persons without diabetes. FEV1 was reduced by 139 mL in diabetic patients, and mean residual FVC was decreased by 251 mL. Similar results were found among former smokers and those who had never smoked; however, in these groups, the differences between diabetic patients and persons without diabetes did not reach significance.

To exclude the possibility that diabetes therapies were responsible for these findings, the authors excluded all treated patients. They found that as blood glucose levels increased, mean residual FEV1 decreased significantly, independent of smoking status. There was a similar correspondence between blood glucose levels and residual FVC.

The authors speculated that systemic inflammation caused by smoking influences glycemia as well as lung function.

Walter RE, Beiser A, Givelber RJ, et al. Association between glycemic state and lung function. Am J Respir Crit Care Med. 2003;167:911-916.

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