Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An increasing incidence of tuberculosis has been recorded in areas where both human immunodeficiency virus (HIV) and Mycobacterium tuberculosis are prevalent. 98% of HIV-associated tuberculosis cases occur in developing countries, most notably sub-Saharan Africa. This trend has led to the consideration of tuberculosis prevention therapy for HIV-infected patients. The efficacy of isoniazid for this purpose has been demonstrated in numerous clinical trials, but its application has been limited by concerns about hepatotoxicity, non-adherence, drug resistance, and costs. Recommended is the approach adopted in the US of providing a six-month course of isoniazid to those with a positive tuberculin skin test reaction and epidemiologic risk factors; for those already infected with HIV, 12 months of treatment is suggested. Rifampicin preventive therapy is recommended for those infected by isoniazid-resistant bacilli. Needed are studies to assess operational feasibility, cost-benefits, the use of life-long isoniazid preventive therapy in areas of high tuberculosis transmission, and alternative regimens such as short-course multidrug treatment.
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PMID:Preventive therapy for tuberculosis in HIV infection: the promise and the reality. 754 9

Tuberculosis-control programmes are compromised by the increased frequency of multidrug-resistant strains of Mycobacterium tuberculosis. We used the polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) analysis techniques to establish the molecular basis of resistance in 37 drug-resistant isolates of M tuberculosis, and correlated these findings with clinical and antibiotic-sensitivity data. Resistance to isoniazid was found in 36 strains, 16 of which were also resistant to ethionamide. Of the 36 isoniazid-resistant strains, 23 had mutations in the katG gene, and 5 of these also had mutations in the inhA gene. A further 5 strains had alterations in the inhA locus without the katG gene being mutated. Rifampicin resistance was less frequent (13 strains) and usually associated with isoniazid resistance (11 of 13 strains). Mutations in the rpoB gene were detected for all these rifampicin-resistant isolates. Mutations in the rpsL and rrs genes, associated with streptomycin resistance, were found in 13 of 25 and 2 of 25 streptomycin-resistant strains, respectively. The same chromosomal mutations, or combinations of mutations, were found in strains displaying single or multidrug resistance, from cases of both primary and secondary resistance, and from patients infected with human immunodeficiency virus. Thus, multidrug resistance is not due to a novel mechanism and tuberculosis chemotherapy is not subject to a new threat.
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PMID:Implications of multidrug resistance for the future of short-course chemotherapy of tuberculosis: a molecular study. 791 56

A potential pharmacokinetic interaction between rifampin (Rimactan, Rifadin) and zidovudine (AZT, Retrovir) was investigated in the population of human immunodeficiency virus-infected patients at our hospital. The results from four patients who were on long-term (> or = 6 months) combination therapy with zidovudine and rifampin are presented. In all cases of combined use of zidovudine and rifampin, a lower area under the plasma concentration-time curve (AUC) and, consequently, a higher apparent clearance of zidovudine were found, compared with a reference population of zidovudine users. Patients had a low to normal maximum concentration of zidovudine in plasma. Elimination half-lives were normal in all but one patient. Zidovudine glucuronide concentrations were determined in three patients and three control subjects. The patients all had relatively higher peak plasma concentrations and higher AUCs of zidovudine glucuronide than the control subjects. In one patient, zidovudine and zidovudine glucuronide were also measured 2.5 months after discontinuation of rifampin. The AUC of zidovudine increased by a factor of 2. These data are in agreement with an enzyme-inducing effect of rifampin on the glucuronidation of zidovudine. They indicate that long-term combination therapy of rifampin and zidovudine leads to increased clearance of zidovudine, which may have therapeutic consequences.
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PMID:Pharmacokinetic interaction between rifampin and zidovudine. 836 70

This report updates and replaces previous recommendations regarding the use of Bacillus of Calmette and Guerin (BCG) vaccine for controlling tuberculosis (TB) in the United States (MMWR 1988;37:663-4, 669-75). Since the previous recommendations were published, the number of TB cases have increased among adults and children, and outbreaks of multidrug-resistant TB have occurred in institutions. In addition, new information about the protective efficacy of BCG has become available. For example, two meta-analyses of the published results of BCG vaccine clinical trials and case-control studies confirmed that the protective efficacy of BCG for preventing serious forms of TB in children is high (i.e., > 80%). These analyses, however, did not clarify the protective efficacy of BCG for preventing pulmonary TB in adolescents and adults; this protective efficacy is variable and equivocal. The concern of the public health community about the resurgence and changing nature of TB in the United States prompted a re-evaluation of the role of BCG vaccination in the prevention and control of TB. This updated report is being issued by CDC, the Advisory Committee for the Elimination of Tuberculosis, and the Advisory Committee on Immunization Practices, in consultation with the Hospital Infection Control Practices Advisory Committee, to summarize current considerations and recommendations regarding the use of BCG vaccine in the United States. In the United States, the prevalence of M. tuberculosis infection and active TB disease varies for different segments of the population; however, the risk for M. tuberculosis infection in the overall population is low. The primary strategy for preventing and controlling TB in the United States is to minimize the risk for transmission by the early identification and treatment of patients who have active infectious TB. The second most important strategy is the identification of persons who have latent M. tuberculosis infection and, if indicated, the use of preventive therapy with isoniazid to prevent the latent infection from progressing to active TB disease. Rifampin is used for preventive therapy for persons who are infected with isoniazid-resistant strains of M. tuberculosis. The use of BCG vaccine has been limited because a) its effectiveness in preventing infectious forms of TB is uncertain and b) the reactivity to tuberculin that occurs after vaccination interferes with the management of persons who are possibly infected with M. tuberculosis. In the United States, the use of BCG vaccination as a TB prevention strategy is reserved for selected persons who meet specific criteria. BCG vaccination should be considered for infants and children who reside in settings in which the likelihood of M. tuberculosis transmission and subsequent infection is high, provided no other measures can be implemented (e.g., removing the child from the source of infection). In addition, BCG vaccination may be considered for health-care workers (HCWs) who are employed in settings in which the likelihood of transmission and subsequent infection with M. tuberculosis strains resistant to isoniazid and rifampin is high, provided comprehensive TB infection-control precautions have been implemented in the workplace and have not been successful. BCG vaccination is not recommended for children and adults who are infected with human immunodeficiency virus because of the potential adverse reactions associated with the use of the vaccine in these persons. In the United States, the use of BCG vaccination is rarely indicated. BCG vaccination is not recommended for inclusion in immunization or TB control programs, and it is not recommended for most HCWs. Physicians considering the use of BCG vaccine for their patients are encouraged to consult the TB control programs in their area.
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PMID:The role of BCG vaccine in the prevention and control of tuberculosis in the United States. A joint statement by the Advisory Council for the Elimination of Tuberculosis and the Advisory Committee on Immunization Practices. 860 27

Rifampin, an agent known to decrease the half-life of methadone, and rifabutin are two rifamycins that are structurally similar and share mechanisms of action. Hence the possibility of a drug-drug interaction between rifabutin and methadone was evaluated in 24 methadone-maintained, former injecting drug users infected with the human immunodeficiency virus. The study was an open-label, drug-drug interaction and safety trial in which patients were followed for 15 days. Each patient received rifabutin 300 mg as a single dose concomitantly with their individualized methadone dosage. No significant differences in methadone peak plasma concentration, time to peak plasma concentration, area under the plasma concentration-time curve, systemic clearance or renal clearance was observed in the presence of rifabutin. Seventy-five percent of the patients reported at least one symptom of narcotic withdrawal during the study, however, these symptoms were mild. A relationship between the development of narcotic withdrawal and methadone systemic exposure could not be established. Concurrent administration of rifabutin and methadone appeared to be safe in human immunodeficiency virus-infected injecting drug users maintained on stable doses of methadone and is not expected to produce any significant changes in the pharmacokinetics of methadone in these patients.
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PMID:Lack of a pharmacologic interaction between rifabutin and methadone in HIV-infected former injecting drug users. 895 45

The population pharmacokinetics of dapsone were examined in human immunodeficiency virus-infected patients receiving dapsone at a dosage of 100 mg twice weekly for the prevention of Pneumocystis carinii pneumonia. Nonlinear mixed-effect modeling was used to determine the best pharmacostatistical model for the data. A one-compartment open model with first-order absorption and elimination was used as the structural pharmacokinetic model. Several covariates were tested for their influence on pharmacokinetic parameters. Rifampin was found to increase the values of clearance/bioavailability (CL/F) and volume of distribution/ bioavailability (V/F) by approximately 70%. CL/F and V/F were 1.83 liters/h and 69.6 liters, respectively, for patients not taking rifampin. The effect of rifampin on the pharmacokinetic parameters of dapsone was appreciably less than expected on the basis of studies with healthy volunteers. Increased bilirubin levels were associated with a significant decrease in the absorption rate constant (Ka). However, this finding may be considered clinically irrelevant because the post hoc Bayesian estimates of Ka for patients with high bilirubin levels ( > 1.2 mg/dl) were at the lower bound of the values for patients with normal bilirubin levels. The value of Ka was 0.957 h-1 for a patient with a bilirubin level of 0.7 mg/dl. After inclusion of covariates in the model, the interpatient variability was 35% for CL/F, not significant for V/F, and 85% for Ka. Simulation of plasma concentration-versus-time curves indicated that the administration of 100 mg of dapsone biweekly is associated with sustained dapsone levels in the plasma of the majority of the patients. Dosage adjustments for patients concomitantly treated with rifampin may be necessary.
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PMID:Population pharmacokinetics of dapsone administered biweekly to human immunodeficiency virus-infected patients. 912 33

Rifampin therapy is an infrequently reported cause of pseudomembranous colitis. A low index of suspicion may account for this lack of recognition. Awareness of this potentially hazardous complication of rifampin therapy is encouraged, especially since increasing numbers of patients infected with the human immunodeficiency virus, who may have diarrhea from other etiologies, require rifampin therapy.
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PMID:Delayed onset of pseudomembranous colitis after rifampin therapy. 919 44

Hemodialysis permits a long term survival to patients with End Stage Renal Disease (E.S.R.D.). However the patients ongoing hemodialysis presented a immunodeficiency and a important modification of drugs biodisponibility. Tuberculosis is an endemic disease in our countries. Extrapulmonary tuberculosis is reported from these two cases among 13 patients treated in C.H.U.A. Le Dantec hemodialysis center. Clinical symptoms are not specific bacteria is not found. Diagnosis is obtained by a bundle of arguments. Antituberculosis treatment need to be adjusted in this field. Even if Rifampicine can be administrated at normal dose. The others drugs must be adapted on their clearance and the underlying disease. The two patients presented psychiatrical symptoms motivating a reduction of isoniazide dose witch threshold toxicity is lowered by renal failure state. These observations must increase watchfulness on nephrologist of undeveloping countries, confronted with tuberculosis renewed out break.
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PMID:[Tuberculosis among hemodialysis patients in Dakar, apropos of 2 cases]. 987 94

Rifampin is the cornerstone of short-course chemotherapy for the treatment of tuberculosis (TB). Rifampin monoresistance (RMR) is less common than resistance to isoniazid alone or in combination with other antituberculous medications. We conducted a retrospective case-control study to identify risk factors for RMR-TB. Complete records for 21 of a total of 26 RMR patients from 1990 to 1997 were available for review, and were compared with those of 48 patients with drug-susceptible TB, controlling for year of diagnosis. Cases more frequently had a history of TB than did controls (61% versus 22%, p < 0.01), and were more often human immunodeficiency virus (HIV) positive (81% versus 46%, p = 0.02). With control for HIV status, cases were more likely to have extrapulmonary involvement (47.6% versus 11.6%, p = 0.05). Four cases (19%) and one control (2. 1%) died (p = 0.02) during hospitalization. Cases more often had a history of incarceration (71.4% versus 37.5%, p = 0.09). Among the 13 cases with a history of TB, five had evidence of malabsorption (vomiting and/or diarrhea), versus none of the 11 controls with prior TB. These data support the hypothesis that RMR is seen primarily in individuals with a history of TB and who are HIV positive. Cases were frequently noncompliant with previous treatment for TB, had a history of incarceration, and had poor outcomes.
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PMID:Risk factors for rifampin-monoresistant tuberculosis: A case-control study. 992 59

Rifampin is a potent inducer of cytochrome P-450 oxidative enzymes. A few examples of well-documented clinically significant interactions include interactions with warfarin, oral contraceptives, cyclosporine, glucocorticoids, ketoconazole or itraconazole, theophylline, quinidine sulfate, digitoxin or digoxin, verapamil hydrochloride, human immunodeficiency virus-related protease inhibitors, zidovudine, delavirdine mesylate, nifedipine, and midazolam. Recent reports have demonstrated clinically relevant interactions with numerous other drugs, such as buspirone hydrochloride, zolpidem tartrate, simvastatin, propafenone hydrochloride, tacrolimus, ondansetron hydrochloride, and opiates. Rifabutin reduces serum concentrations of antiretroviral agents, but less so than rifampin. To avoid a reduced therapeutic response, therapeutic failure, or toxic reactions when rifampin is added to or discontinued from medication regimens, clinicians need to be cognizant of these interactions. Enhanced knowledge of known interactions will continue to develop, including research on the induction of specific cytochrome P-450 isoenzymes and on the importance of the P-glycoprotein transport system. New rifampin and rifabutin interactions will be discovered with further investigations.
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PMID:Rifampin and rifabutin drug interactions: an update. 1199 7


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