PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “THIACETAZONE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Cutaneous hypersensitivity reactions to thiacetazone, HIV infection and thiacetazone concentrations in plasma.

We have studied the relationship between the plasma concentration-time profile of thiacetazone over the 24 h between doses [AUC(0.24h)] and the incidence of cutaneous reactions among HIV-infected patients with tuberculosis in Kenya. Cutaneous reactions due to thiacetazone occurred in 4/14 [28.6%] HIV+ve patients compared with 3/47 [6.4%] HIV-ve patients [RR = 4.48, 95% CI-1.1 to 17.7], and all resolved on alternative therapy. Among the HIV+ve patients, those with cutaneous reactions had higher AUC(0.24h) values, although the difference was not significant. These results do not exclude pharmacokinetic change as being at least partly responsible for cutaneous reactions to TCZ in HIV+ve patients, and do not refute an immunological basis for the reaction. With regard to the operational use of TCZ in Africa, there is no indication that a modification of the dose will reduce the frequency of drug reactions.

Adolescent↗

Life-threatening cutaneous reactions to thiacetazone-containing antituberculosis treatment in Kumasi, Ghana.

Antituberculosis treatment containing thiacetazone is associated with a high incidence of life-threatening cutaneous drug reactions in patients infected with the human immunodeficiency virus (HIV). In order to develop a local policy concerning the use of this drug, a study was undertaken to determine the incidence of such reactions in a total of 1063 Ghanaian adult patients treated for pulmonary tuberculosis (PTB) with thiacetazone-containing regimens. The incidence was retrospectively determined in 3 different treatment groups, comparing: (A) unselected use of thiacetazone; (B) exclusion of thiacetazone from all patients with positive HIV serology; (C) selective exclusion of thiacetazone from patients with clinical criteria suggesting HIV infection plus education of health workers and patients. Of the 408 patients in group A receiving thiacetazone, 9 (2.2%) developed life-threatening cutaneous reactions and 7 of these were HIV-positive. Overall, 6.8% of HIV-positive patients compared to 0.65% of HIV-negative patients developed severe reactions (P < 0.01; relative risk = 10.5). Six of the 9 patients with reactions died. All 379 patients in group B were screened for HIV antibodies and positive cases (23%) received a regimen in which thiacetazone was substituted by ethambutol. In contrast to Group A, only one HIV-negative patient (0.26%) developed a severe cutaneous reaction (P = 0.02). Among 276 patients in group C, thiacetazone was substituted with ethambutol only in those with clinical evidence of HIV infection (8%) and staff and patients were educated about early recognition of the side-effect. With this policy, these were no admissions with severe cutaneous reactions compared to 2.2% of those in group A (P = 0.01). In conclusion, a policy of selective use of thiacetazone in the treatment of PTB based on clinical criteria combined with patient and staff education was found to be a practical and cost-effective strategy combating severe cutaneous reactions to thiacetazone.

AIDS-Related Opportunistic Infections↗

Characteristics of a cytosolic arylacylamidase metabolizing thiacetazone.

The N-deacetylation of thiacetazone, an antitubercular drug possessing hepatotoxic side effects, by an exclusively cytosolic arylacylamidase has been identified in the liver and kidney of rat by monitoring the appearance of its metabolite p-aminobenzaldehydethiosemicarbazone spectrophotometrically. Studies toward its characterization in liver cytosol revealed that the hydrolase possesses a broad pH optimum ranging from 6.0 to 9.0. The Km and Vmax values for the N-deacetylation of thiacetazone are 5.7 x 10(-4) M and 0.123 nmol of p-aminobenzaldehydethiosemicarbazone formed/min/mg cytosolic protein, respectively. The ability to metabolize thiacetazone was the same in the livers of cat, mouse and human, but lagged significantly in that of rat. Among the biodegradable esters examined as potential rivals of thiacetazone, only aspirin competitively inhibited thiacetazone hydrolysis (Ki = 2.1 x 10(-4) M). Discrimination of cytosolic thiacetazone N-deacetylase from nonspecific p-nitrophenylacetate esterase on the basis of their differential reactivity toward various inhibitors and activators disclosed that low concentrations of p-chloromercuribenzoate, AgNO3 and CuSO4 selectively undermine the activity of thiacetazone N-deacetylase, whereas SKF 525-A, ZnSO4 and FeCl3 are effective inhibitors of p-nitrophenylacetate esterase. However, divalent ions (Ca++ and Mg++) and EDTA failed to alter the activity of the enzyme. Besides, thiacetazone metabolism was significantly retarded upon exposure to malathion. Notably, Nal/Kl stimulated the N-deacetylase activity as a function of iodide concentration. The hydrolysis of thiacetazone in the liver and kidney remained uninduced by phenobarbital, 3-methylcholanthrene or benzo(a)pyrene (80 mg/kg, p.o., 8 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Amidohydrolases↗

Chromosome-damaging action of isoniazid and thiacetazone on human lymphocyte cultures in vivo.

Antitubercular drugs in general are given in various combinations, one being isoniazid and thiacetazone. In the present study, was evaluated the in vivo chromosome-damaging effects of a combination of these two drugs in 72 h lymphocyte cultures. Chromosome aberrations were significantly increased in the patients treated with INH and thiacetazone as compared with two types of controls: (1) tuberculosis patients before starting the drug treatment and (2) individuals from the general population. The most frequently observed aberrations were chromatid breaks and gaps. It has been shown that individually, isoniazid may not be clastogenic on human chromosomes in therapeutic doses. The effects of thiacetazone on human chromosomes are not known. Consequently, the enhancement in chromosomal aberrations in the drug-exposed patients may be due to a synergistic effect of isoniazid and thiacetazone or to the clastogenic effects of thiacetazone alone.

Adolescent↗

Adverse cutaneous reactions to thiacetazone for tuberculosis treatment in Tanzania.

Because thiacetazone has been linked with serious adverse cutaneous reactions, we undertook 1 year of systematic surveillance for cutaneous thiacetazone-associated adverse reactions within the national tuberculosis programme of Tanzania. For individual cases, we collected information on age, sex, interval between commencing thiacetazone-containing treatment and occurrence of adverse reaction, most severe clinical presentation (toxic epidermal necrolysis, rash without necrolysis, itching without rash), and outcome (dead or alive) within 2 weeks of onset. Univariate and multivariate analyses were done of variables relevant to outcome. 1273 patients with adverse reactions were reported. The frequency of fatal outcome from any cutaneous reaction was 3.1 per 1000 among all tuberculosis patients, and 19.1% among patients with toxic epidermal necrolysis. About 60% of all adverse reactions and deaths occurred within 20 days of starting thiacetazone. Case fatality from adverse cutaneous reactions was considerably less frequent than reported previously, suggesting that improved management might allow retention of thiacetazone in the armamentarium of national tuberculosis programmes even where infection with HIV is prevalent.

Adult↗

Cutaneous hypersensitivity reactions due to thiacetazone in the treatment of tuberculosis in Zambian children infected with HIV-I.

Tuberculosis is one of the most common infections in Zambian adults and children infected with HIV. In Africa, cutaneous hypersensitivity reactions attributed to thiacetazone during treatment of tuberculosis in adults infected with HIV-I have been well documented. This study monitored adverse drug reactions during treatment for tuberculosis over an 18 month period (1 April 1990 to 31 October 1991) in 237 children with a clinical diagnosis of tuberculosis (125 boys and 112 girls; 88/237 (37%) infected with HIV-I) and 242 control children (149 boys and 93 girls; 26/242 (11%) infected with HIV-I). Twenty two (9%) of the 237 children with tuberculosis developed hypersensitivity skin reactions during the course of treatment. Adverse skin reactions were seen more often in children infected with HIV than in those who were not (odds ratio 11.65, 95% confidence interval 3.07 to 34.88). These represented 19 (21%) of 88 children infected with HIV and three (2%) of 149 children not infected with HIV. These skin reactions occurred after a period of treatment ranging between two and four weeks among 14 children receiving the HST (isoniazid, streptomycin, thiacetazone) regimen and eight children receiving the HSTR (isoniazid, streptomycin, thiacetazone, rifampicin) regimen. Twelve (55%) of the 22 children who reacted adversely to treatment developed the Stevens-Johnson syndrome. All 12 of these children with the Stevens-Johnson syndrome were infected with HIV. The mortality among these children who developed the Stevens-Johnson syndrome was 91% (11 of 12 died within three days of the onset of the reaction). No further reactions were observed in the 11 children who recovered from the cutaneous hypersensitivity reactions after thiacetazone was discontinued over a period of six months of further treatment of tuberculosis. The results of this study were in part responsible for the recommendations put forward by the World Health Organization to avoid the use of thiacetazone in the treatment of tuberculosis in children infected with HIV.

AIDS-Related Opportunistic Infections↗

Thiacetazone--avoid like poison or use with care?

Recent 5 reports of severe cutaneous hypersensitivity reactions in patients infected with human immunodeficiency virus (HIV) and with tuberculosis treated with thiacetazone have prompted the World Health Organization to advise against the use of thiacetazone in patients known, or suspected, to be infected with HIV. Because the poorest countries will have great difficulty in replacing thiacetazone, the history, metabolism and possible mechanisms underlying the toxicity of this inexpensive, but problematic, drug are reviewed. Guidelines for National Tuberculosis Control Programme policies in response to thiacetazone toxicity are discussed, taking into account the differing levels of resources available to developing countries.

Adult↗

Randomised trial of thiacetazone and rifampicin-containing regimens for pulmonary tuberculosis in HIV-infected Ugandans. The Makerere University-Case Western University Research Collaboration.

Among HIV-positive patients who received treatment for active tuberculosis, thiacetazone has been associated with cutaneous hypersensitivity and recurrent tuberculosis. No controlled trials have investigated the safety and efficacy of thiacetazone-containing regimens compared with alternative regimens among patients with HIV. In a randomised clinical trial of 191 HIV-positive patients with active pulmonary tuberculosis, we examined the safety and short-term efficacy of isoniazid, rifampicin, and pyrazinamide for two months followed by isoniazid and rifampicin for seven months (RHZ) compared with streptomycin, thiacetazone, and isoniazid for two months followed by thiacetazone and isoniazid for ten months (STH). Between May, 1990, and September, 1991, 191 HIV-positive adult Ugandan patients with acid-fast bacilli sputum smear-positive pulmonary tuberculosis (93% confirmed by culture) received either STH or RHZ. Subjects had a standard evaluation that included Mantoux skin test, complete blood count with differential white blood cell count, and chest radiography. After starting therapy, subjects were followed-up over one year for three outcomes: complications of anti-tuberculosis therapy, early sterilisation of cultures, and survival. Of 191 eligible subjects, 90 received STH and 101 received RHZ. The overall one-year survival was similar for STH and RHZ (65% vs 72%), but when controlled for baseline differences in Mantoux reaction size and absolute lymphocyte count, the relative risk of death for STH compared with RHZ was 1.57 (95% CI 1.0-2.48). Overall, 12 adverse drug reactions occurred in the STH arm (18.2 reactions per 100 person years [PYO]) compared with one in the RHZ arm (1.6 reactions per 100 PYO) for a relative risk of 11.7 (95% CI 1.52-90.0). 10 cutaneous reactions occurred in the STH arm (15.2 events per 100 PYO) compared with one event in the RHZ arm (1.6 events per 100 PYO) for a relative risk of 9.7 (95% CI: 1.24, 75.8). A greater proportion of RHZ patients compared with STH patients had sterilised their sputum within two months (74% vs 37%, p < 0.001). In developing countries, rifampicin-containing regimens should be given, when possible, to HIV-positive patients to reduce drug toxicity and to prolong survival.

AIDS-Related Opportunistic Infections↗

Isocratic high-performance liquid chromatographic determination of thiacetazone by direct injection of plasma into an internal surface reversed-phase column.

This report describes the determination of thiacetazone in human and rat plasma by direct-injection high-performance liquid chromatography (HPLC). Plasma filtrate (50 microliters) was injected directly into the internal surface reversed-phase (ISRP) mixed-functional phenyl column (Capcell Pak, 50 x 4.6 mm, 5 microns) and eluted with an aqueous mobile phase containing 7.5% acetonitrile at a flow-rate of 1 ml/min. With UV detection at 322 nm, thiacetazone eluted at 11.0 min whereas endogenous interferences eluted before 5 min. The lower detection limit for a 50-microliter sample at a signal-to-noise ratio of 5 was 63 ng/ml, which was several hundred fold lower than its cytotoxic concentrations determined from in vitro cell line studies. At a concentration range of 0.17 to 2.7 micrograms/ml, the recovery of thiacetazone was 98.0 +/- 4.4% (mean +/- S.D.). The intra- and inter-day coefficients of variation were 3.0 +/- 1.4% and 4.2 +/- 2.1%, respectively. This method was successfully applied to study the pharmacokinetics of thiacetazone in rats. The direct injection method is simple, requires small sample volume and does not require sample extraction, internal standard, or gradient elution.

Animals↗