Respiratory conditions
David M. Luesley, Mark D. Kilby in Obstetrics & Gynaecology, 2016
Isoniazid, rifampicin and ethambutol are used initially. The ethambutol can be stopped when sensitivities show that the other two drugs are adequate. These are then continued for 9 months in total. The most significant toxic side effect of isoniazid in animal and human studies is demyelination (causing a peripheral neuropathy). This can be prevented by supplementation with pyridoxine (vitamin B6). Hepatotoxicity may be more common in pregnancy, and liver function tests should be performed monthly [D]. Most studies do not show a significant elevation in the anomaly rate above the background 2–3 percent in users of rifampicin in pregnancy [B]. Liver enzyme induction, with theoretical vitamin K deficiency, should prompt maternal oral vitamin K supplements in the third trimester to prevent haemorrhagic disease of the newborn. The theoretical risks of fetal ocular toxicity with ethambutol have not been borne out in practice. Although pyrizinamide is usually avoided in pregnancy, there are no data to suggest a harmful effect and it should be used if needed as a second-line agent. Streptomycin, a previous favourite in TB treatment, has well-recognised fetal ototoxicity. Safer alternatives are available.
India’s national TB programme
Helen Macdonald, Ian Harper in Understanding Tuberculosis and Its Control, 2019
Notably, only some informants who viewed taking TB medicine after consuming alcohol as dangerous did in fact not take their meds. However, among those who did take their medication, several reported feeling worried about doing so. Those who waited before resuming medication felt it was safer to miss a dose than risk side effects. Doctors interviewed felt it was important to give patients a strong message that drinking was not permitted while consuming TB medication. A few remembered hearing or reading that one could suffer liver disease and jaundice if one consumed alcohol and isoniazid. Isoniazid does indeed have hepatotoxic side effects known to affect those with pre-existing liver damage—such as that associated with a history of alcohol abuse. However, consuming isoniazid after having an occasional drink has never been associated with harm. Other doctors stated that the strong message never to drink alcohol was really an indirect way of telling patients they should not have sex with their wives when infectious, something not explicitly mentioned. I would also note that those who drank alcohol, even at low levels, were commonly referred to by health staff as ‘alcoholics’ and considered recalcitrant.
Pulmonary complications of solid-organ transplantation
Philippe Camus, Edward C Rosenow in Drug-induced and Iatrogenic Respiratory Disease, 2010
When therapy is initiated at the time of listing, most or all of the recommended 9-month course of isoniazid can often be completed prior to transplantation. In this way, interactions with immunosuppressive drugs that could lead to an enhanced risk of hepatotoxicity can be avoided. The approach to liver transplant candidates and recipients with latent infection is more problematic. There is an understandable reluctance to use isoniazid prior to transplantation because of the presence of severe liver disease, though the drug can be administered safety under close observation.9 The use of isoniazid after liver transplantation is associated with an increased risk of hepatotoxicity, but the risk may be lower when the drug is administered as a single agent rather than as part of a multi-drug antituberculous regimen. If treatment of latent infection with isoniazid is attempted following liver transplantation, liver biopsy should be considered in the setting of elevated liver enzymes, since aetiologies other than drug toxicity (e.g. allograft rejection) may be responsible in up to half of these instances.7 A 4-month course of rifampin is an acceptable alternative to isoniazid and is ideally initiated prior to transplantation in order to avoid interactions with the calcineurin inhibitors.
Treatment for latent tuberculosis infection in low- and middle-income countries: progress and challenges with implementation and scale-up
Published in Expert Review of Respiratory Medicine, 2020
Anthony D. Harries, Ajay M. V. Kumar, Srinath Satyanarayana, Kudakwashe C. Takarinda, Collins Timire, Riitta A. Dlodlo
Isoniazid is the current drug of choice with each country needing to work out whether a 6-month course is sufficient or in the case of people living with HIV whether 36 months or continuous treatment should be given. The most feared side-effect of isoniazid is drug-induced hepatitis, which if unrecognized or identified too late, can be fatal. Programs and civil society need to work out how to avoid and/or quickly identify drug-induced hepatitis in the field, recognizing that in many low- and middle-income countries laboratory support is not readily accessible. One or two publicized cases of fatal isoniazid-induced hepatitis can quickly paralyze a functioning national program delivering treatment for LTBI. Shorter and potentially safer alternative regimens are now available, the most attractive being a 3-month course of weekly rifapentine and isoniazid (3HP – 12 doses in total) or a 1-month course of daily rifapentine and isoniazid (1HP). Important requirements for these shorter courses are regulatory approval in countries where they are most needed and a drastic reduction in the cost of rifapentine. Concerted advocacy and activism are needed to bring down the costs.
Preventive therapy for tuberculosis in rheumatological patients undergoing therapy with biological drugs
Published in Expert Review of Anti-infective Therapy, 2018
Delia Goletti, Linda Petrone, Giuseppe Ippolito, Laura Niccoli, Carlotta Nannini, Fabrizio Cantini
In particular, isoniazid is an oral antibiotic with activity against both intracellular and extracellular Mtb. Daily therapy with isoniazid, for between 6 and 12 months, has been the most common treatment suggested worldwide with an average protective effect for TB of 60% during the observation period [126,127]. The optimal duration of taking isoniazid remains controversial. In 1982, a randomized trial in subjects with fibrotic pulmonary lesions, were isoniazid was administered for 3, 6, and 12 months [127] showed that the risk for developing active TB compared with placebo was reduced by 21%, 65%, and 75%, respectively, after 5 years of follow-up. Successively, it was shown that 6 months of isoniazid regimen is more cost effective than 3 or 12 months of isoniazid regimen [128]. This is in line with the fact that shorter treatment duration is crucial to reduce the side effects of the drugs-hepatotoxicity which ranges from 0.1% to 0.3% [129,130] and to have an increased adherence. Pyridoxine (vitamin B6) supplementation with all isoniazid regimens is recommended to reduce the peripheral neuropathy [131] which may arise at higher likelihood in chronic alcoholics, malnourished persons, and pregnant women or healthy individuals (0.2%) due to the inhibitory effect of isoniazid on the function of pyridoxine metabolites [131,132].
Complications in Intermediate Uveitis: Prevalence, Time of Onset, and Effects on Vision in Short-Term and Long-Term Follow-Up
Published in Ocular Immunology and Inflammation, 2019
Ligia Sancho, Michal Kramer, Adi Koriat, Maya Eiger-Moscovich, Yael Sharon, Radgonde Amer
The majority of patients (n = 67, 70%) had an isolated ocular inflammation (pars planitis) and 28 patients (29%) had an associated systemic inflammatory condition. One patient was treated with isoniazid because of presumed tuberculosis infection. The most commonly associated systemic disease was sarcoidosis encountered in 17 patients (17.7%). Seven had multiple sclerosis (MS) (7.3%), and Behçet’s disease, psoriasis, lupus, and tubulointerstitial nephritis and uveitis (TINU) were encountered in one patient each (1%). Pars planitis was diagnosed at a mean age of 23 years, whereas sarcoidosis and MS were diagnosed at a mean age of 52 years. A statistically significant association was observed between etiology and age at diagnosis (p < 0.001) (Table 1); however, no association was observed between etiology and logMAR VA at presentation.
Related Knowledge Centers
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