[A case of successful desensitization therapy for isoniazid-induced pneumonitis].

A 65-year-old man was admitted to hospital for treatment of pulmonary tuberculosis. He was treated with isoniazid (INH), rifampicin (RFP), ethambutol (EB), and pyrazinamide (PZA). On the 14th day, he developed a fever and interstitial pneumonia, which improved promptly after discontinuation of the antituberculous drugs. Drug lymphocyte stimulation tests against INH, RFP and PZA were negative. However, the provocation test on INH (only) was positive, leading to a diagnosis of pneumonitis caused by INH. We then tried desensitization of INH over a period of two weeks, which was successful and occurred without any clinical event. In the past, five cases of INH-induced pneumonitis were reported, but desensitization of INH did not occur in any. We conclude that physicians should be aware not only of paradoxical reactions but also of drug-induced pneumonitis when a new pulmonary infiltrate develops in the course of tuberculosis treatment. Furthermore, drug desensitization may be possible in some cases of drug-induced pneumonitis.

Effect of carbocysteine on cough reflex to capsaicin in asthmatic patients.

AIMS: Cough, one of the main symptoms of bronchial asthma, is a chronic airway inflammatory disease with functionally damaged bronchial epithelium. Recently, we established an animal model with cough hypersensitivity after antigen challenge and clearly showed the protective effect of carbocysteine in this model. This study was designed to investigate the clinical effect of carbocysteine for cough sensitivity in patients with bronchial asthma. METHODS: The effects of the two orally active mucoregulatory drugs, carbocysteine and ambroxol hydrochloride, on cough response to inhaled capsaicin were examined in 14 patients with stable asthma. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough sensitivity. RESULTS: Geometric mean values of the cough threshold at run-in (baseline) and after 4 weeks' treatment of placebo, 1500 mg day-1 of carbocysteine and 45 mg day-1 of ambroxol hydrochloride were 12.8 micro M (95% confidence interval [CI] 5.5, 29.6), 11.0 micro M (95% CI 4.4, 27.5), 21.0 micro M (95% CI 8.8, 50.2) and 11.6 micro M (95% CI 5.8, 23.3), respectively. The cough threshold for carbocysteine was significantly greater than those of ambroxol hydrochloride (P = 0.047) and placebo (P = 0.047), respectively. CONCLUSIONS: These findings indicate that carbocysteine administration may be a novel therapeutic option for asthmatic patients, especially with cough variant asthma.

Thromboxane antagonism and cough in chronic bronchitis.

BACKGROUND: The increased eicosanoid synthesis has been suggested as the underlying mechanism of chronic productive cough in patients with chronic bronchitis. METHOD: The effects of the orally active thromboxane A2 (TxA2) receptor antagonist seratrodast and the cysteinyl leukotrienes (cLTs) receptor antagonist pranlukast on cough response to inhaled capsaicin were examined in sixteen patients with stable chronic bronchitis. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough sensitivity. RESULTS: The cough threshold was significantly increased compared with placebo after four-week treatment with seratrodast, but not after treatment with pranlukast. CONCLUSIONS: TxA2, but not cLTs, may be a possible modulator augmenting airway cough sensitivity in chronic bronchitis. Thromboxane antagonism may be considered to be one of the therapeutic options for the treatment of chronic productive cough.

[A case of pulmonary tuberculosis initially presented with syndrome of inappropriate secretion of antidiuretic hormone (SIADH)].

A 90-year old man was admitted to a hospital because of consciousness loss with hyponatremia. Although his symptom promptly improved with Na supply, his chest X-ray film showed pulmonary infiltration and direct microscopy of sputum smear was positive for acid-fast bacilli, then he was referred our hospital and was admitted. We made a clinical diagnosis of pulmonary tuberculosis with SIADH based on detailed examinations. But he should neither respiratory symptoms nor fever. He was medicated with the standard antituberculosis drugs with fluid restriction, and his tuberculosis and hyponatremia were improved gradually. We should be more careful about pulmonary tuberculosis irrespective of its severity as a cause of SIADH.