Bronchiolitis treatment

It is a powerful antagonist of histamine, antagonizing its effect on smooth muscle of the bronchioles, bladder and partially the intestines and preventing the dilation of capillaries. Promethazine is used in the treatment of allergic reactions. 

Examination of 13 individuals 5 years after they were occupationally exposed to a chlorine dioxide leak revealed sensitivity to respiratory irritants and nasal abnormalities. Delayed deaths occurred in animals after exposure to 15 0-2 00 ppm for less than 1 hour. Rats exposed daily to 10 ppm died after 10-13 days of exposure effects were nasal and ocular discharge and dyspnea autopsy revealed purulent bronchitis. Another study reported that two to four 15-minute exposures to 5 ppm for 1 month did not alter the blood composition or lung histology of rats similar exposures to 10-15 ppm caused bronchitis, bronchiolitis, catarrhal alveolar lesions, and peribronchial infiltration. Lesions healed within 15 days after treatment. Rats and rabbits exposed for 30 days to 5 or 10 ppm (2 hours/day) had localized bronchopneumonia with elevated leukocyte counts slight reversible pulmonary lesions were found after exposures of 2.5ppm for 4-7 hours/day. No adverse reactions were... 

The clinicians noted that although the first patient responded well to steroid therapy, steroids may be less useful in more severe cases of bronchiolitis obliterans. Specifically, steroid treatment should be stopped if no improvement is seen during the first days because this treatment may increase the risk of lung infection in the presence of a denuded lung epithelium. 

Although anticholinesterase agents can be used in the treatment of atony of the bladder and adynamic ileus, they are contraindicated in cases of mechanical obstruction of the intestine or urinary tract. Caution should also be used in giving these drugs to a patient with bronchial asthma or other respiratory disorders, since they will further constrict the smooth muscle of the bronchioles and stimulate respiratory secretions. 

Ribavirin aerosol (Virazole) is indicated in the treatment of high-risk infants and young children with severe bronchiolitis or pneumonia due to RSV infection. Treatment is most effective if begun within 3 days of the onset of symptoms. 

In contrast to an additive effect, drugs with opposite actions may essentially cancel each other out, thus negating or reducing the beneficial effects of one or both medications. A drug that causes bronchodilation (i.e., for the treatment of asthma) will be negated by an agent that constricts the bronchioles. 

Metaproterenol [met a proe TER a nole], although chemically similar to isoproterenol, is not a catecholamine and is resistant to methyla-tion by COMT. It can be administered orally or by inhalation. The drug acts primarily at p2 receptors, producing little effect on the heart. Metaproterenol produces dilation of the bronchioles and improves airway function. The drug is useful as a bronchodilator in the treatment of asthma and to reverse bronchospasm (Figure 6.13). 

Ghanei, M., Shohrati, M., Harandi, A.A., Eshraghi, M., Aslani, J., Alaeddini, F., Manzoori, H. (2007). Inhaled corticosteroids and long-acting beta 2-agonists in treatment of patients with chronic bronchiolitis following exposure to sulfur mustard. Inhal. Toxicol. 19 889-94. 

Bronchiolitis obliterans has been reported in an 18-year-old female non-smoker with ulcerative cohtis, 3 months after reintroduction of mesalazine 1.6 g/day orally (41). She recovered after mesalazine withdrawal and treatment with glucocorticoids. 

A limited form of Wegener s granulomatosis with a bronchiolitis obliterans organizing pneumonia-hke variant has been reported in a 19-year-old man, a non-smoker, with ulcerative colitis, 6 months after the introduction of mesalazine 2.25 g tds orally (43). He recovered after mesalazine withdrawal and treatment with glucocorticoids. 

Interferon alfa was also suspected to be involved in one case of biopsy-proven bronchiolitis obliterans-organizing pneumonia (41). Clinical symptoms of pneumonitis appeared 3-12 weeks after the onset of interferon alfa therapy, and after withdrawal of treatment they usually completely resolved, either spontaneously or after a short course of glucocorticoid treatment. Immune-mediated pulmonary toxicity involving the activation of T cells was considered as a likely mechanism. The uncommon features of bronchiolitis obliterans-organizing pneumonia have been reported in three other patients who received interferon alfa together with ribavirin or cytosine arabino-side (42,43). 

A 49-year-old man had a progressive unproductive cough and right hemithoracic pain after 3 months of interferon beta-la 30 micrograms/week for multiple sclerosis. A CT scan showed a right basal pulmonary infiltrate and transbronchial biopsies showed features consistent with bronchiolitis obliterans with organizing pneumonia. The lesions resolved fully on interferon beta-la withdrawal and prednisone treatment. 

Ferriby D, Stojkovic T. Clinical picture bronchiolitis obliterans with organising pneumonia during interferon beta-la treatment. Lancet 2001 357(9258) 751. 

Ribavirin seems to be effective, but the lengthy administration that has been used is a disadvantage. There is now evidence that shorter courses (two hours three times per day) of ribavirin are as useful as standard therapy (18 hours per day) [207]. Aerosolized ribavirin has been used with variable success for children ventilated for bronchiolitis caused by RSV [208-210]. The more recent evidence casts some doubt on the efficacy of this aerosol treatment. Ribavirin aerosol has also been used for treatment or prophylaxis following bone marrow transplantation [211,212], but controlled trials are needed to better clarify efficacy. Considering the magnitude of this problem, definitive trials to clearly define efficacy would be welcome. 

Gmninger, 1956). Willems report on Iranian casualties treated in western European hospitals demonstrates the effect of medical advances since World War I. Chnical files of 65 of these casualties were studied in detail (Willems, 1989). Eight patients died between 6 and 15 days after exposure. One patient died 185 days after exposure he had received ventilatory support for an extended period because of severe bronchiolitis comphcated by a series of loculate pneumothoraces. Most patients returned to Iran in fairly good condition after 2-10 weeks of treatment. The duration of hospitalization was determined mainly by the time needed for heating of the deeper skin lesions. Because some of the most severe patients were sent to Europe, there was a 14% mortahty rate, compared to the 3% seen overall in World War I. 

Respiratory syncytial virus is the most common cause of acute bronchiolitis, an infection that mostly affects infants during their first year of life. In the well infant, bronchiolitis is usually a self-limiting viral illness, whereas in the child with underlying respiratory or cardiac disease or both, the child may develop severe respiratory compromise (failure) necessitating in-hospital treatment, such as rehydration, oxygen, and in select patients, bronchodilators, ribavirin aerosol, or both. 

Klassen TP. Recent advances in the treatment of bronchiolitis and laryngitis. Pediatr CUn North Am 1997 44 249-261. 

Dudek AZ, Mahaseth H, DeFor TE, WeisdorfDJ. Bronchiolitis obUterans in chronic graft-versus-host disease analysis of risk factors and treatment outcomes. Biol Blood Marrow Transplant 2003 9 657-666. 

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