[A case of pseudomembranous colitis associated with rifampicin therapy in a patient with rectal cancer and gastrointestinal tuberculosis]

Pseudomembranous colitis (PMC) is known to be associated with the administration of antibiotics which alter normal gastrointestinal flora and allow overgrowth of Clostridium difficile. Most cases of rifampicin-induced PMC are seen in patients with pulmonary tuberculosis, but not with gastrointestinal tuberculosis. We report a case of PMC associated with rifampicin therapy in a patient with gastrointestinal tuberculosis. A 65-year-old female patient with rectal cancer and gastrointestinal tuberculosis was admitted due to abdominal pain and diarrhea. She was treated with anti-tuberculosis agents containing rifampicin. On colonoscopic examination, mucoid exudates and yellowish plaque lesions were observed. Anti-tuberculosis agents were stopped, and the patient was treated with metronidazole. Symptoms were relieved and did not recur when all the anti-tuberculosis agents except rifampicin were started again. When a patient complains of abdominal pain or diarrhea while taking rifampicin, the physician should consider the possibility of rifampicin-associated PMC.

Addison's disease induced by miliary tuberculosis and the administration of rifampicin

We herein report a rare occurrence of Addison's disease caused by acute adrenal gland tuberculosis occurring in association with miliary tuberculosis and the administration of rifampicin. An 82-year-old woman with miliary tuberculosis was treated with antituberculous chemotherapeutic agents including rifampicin (RFP), but she still demonstrated general malaise in addition to hyponatremia. Abdominal CT showed an enlargement of the right adrenal gland. However, after discontinuing RFP, the patient's symptoms improved. We carefully reinitiated the administration of RFP. The patient's condition thereafter did not worsen, and the treatment could thus be maintained. It is extremely important to immediately recognize adrenal crisis precipitated by the administration of RFP.

Pharmacokinetics of efavirenz when co-administered with rifampin in TB/HIV co-infected patients: pharmacogenetic effect of CYP2B6 variation

The goal of this study was to determine the effect of CYP2B6 genetic variation on the steady-state pharmacokinetics of efavirenz (600 mg/d) in TB/HIV co-infected patients receiving concomitant rifampin, a potent CYP inducer. In the 26 patients studied, CYP2B6 c.516GG, GT, and TT genotype frequencies were 0.27, 0.50, and 0.23, respectively. Mean plasma efavirenz area under the curve was significantly higher in patients with CYP2B6 c.516TT than in those with GT (107 vs 27.6 microg x h/mL, P< .0001) or GG genotype (107 vs 23.0 microg x h/mL, P< .0001). Apparent oral clearance (CL/F) was significantly lower in patients with CYP2B6 c.516TT than in those with GT genotype (2.1 vs 8.4 mL/min/kg, P<0.0001) and GG genotype (2.1 vs 9.9 mL/min/kg, P< .0001). No differences in efavirenz exposure or CL/F existed between patients with CYP2B6 c.516GT and GG genotypes. Our results indicate that CYP2B6 c.516TT genotype can be used to identify efavirenz poor metabolizers in patients co-treated with rifampin.

Hypoadrenalism is not associated with early mortality during tuberculosis treatment in Malawi

SETTING

In the developing world, early mortality within 1 month of commencing tuberculosis (TB) treatment is high, particularly with human immunodeficiency virus (HIV) co-infection. In Malawi, 40% of those who die do so in the first month of treatment. Reasons remain unclear and may include delayed diagnosis, opportunistic infections, immune restoration inflammatory syndrome (IRIS) or malnutrition. One possible contributing factor is underlying hypoadrenalism associated with TB-HIV, exacerbated by rifampicin (RMP) induction of P450 and glucocorticoid metabolism.

OBJECTIVE

To assess the prevalence of hypoadrenalism in TB patients before and after commencement of TB treatment, and relationship with early mortality.

DESIGN

Prospective descriptive study assessing hypoadrenalism before and after anti-tuberculosis treatment, HIV status and outcome up to 3 months post-treatment.

RESULTS

Of 51 patients enrolled, 29 (56.9%) were female (median age 32 years, range 18-62). Of 43 patients HIV-tested, 38 (88.3%) were HIV-positive and 15.7% died within the first month. At 3 months, 11 (21.6%) were known to have died. Adequate cortisol levels were found in 49/51 (95.9%) before commencing RMP. Neither of the two with reduced response died. All 34 patients revealed adequate cortisol responses at 2 weeks.

CONCLUSION

No evidence of hypoadrenalism was found in this first study to assess adrenal function and outcome of anti-tuberculosis treatment.

Successful use of rifampicin for Hispanic foreign-born patients with latent tuberculosis infection

SETTING

Four months of rifampicin (4R) is recommended for the treatment of latent tuberculosis infection (LTBI), although data regarding its use are limited. The majority of tuberculosis (TB) cases in the USA occur among foreign-born persons.

OBJECTIVE

To determine tolerability, hepatotoxicity and completion rates associated with 4R among foreign-born persons.

DESIGN

We retrospectively evaluated 4R treatment among a cohort of predominantly Hispanic foreign-born LTBI patients in four Middle-Tennessee public health clinics from February 2000 to February 2004. Patients' charts were reviewed to abstract demographic, social and clinical data. 4R completion rates, new symptoms and hepatotoxicity (serum aminoalanine transferase >or=120U/l with gastrointestinal symptoms or >or=200 regardless of symptoms) were evaluated.

RESULTS

Of 749 patients treated, 571 (76%) completed 4R. Among all subjects, Hispanics had a lower risk of non-completion (OR 0.6, 95%CI 0.4-0.7) than non-Hispanics. Among non-Hispanic subjects, the risk of non-completion was higher for Blacks than non-Blacks (adjusted OR 2.6, 95%CI 1.5-4.7), but was lower for foreign-born than non-foreign-born subjects (adjusted OR 0.5, 95%CI 0.2-0.9). During treatment, 85 subjects (11%) developed new symptoms, and hepatotoxicity occurred in three patients.

CONCLUSION

With high completion rates and minimal side effects, 4R is a favorable LTBI treatment regimen for Hispanic and other foreign-born patients.

[Rezonizat and cycloserine in complex therapy of drug resistant tuberculosis (comparative studies)]

An open comparative investigation of the Russian drugs rezonizat and cycloserine was performed. The studies made it possible to recommend the use of rezonizat in complex therapy of patients with drug resistant tuberculosis. Higher activity and better tolerability of rezonizat vs. cycloserine was shown.

[A case of multi-drug resistant tuberculosis showing psychiatric adverse effect by cycloserine]

A 45-year-old man with multi-drug resistant tuberculosis were referred to our hospital for treatment. We started chemotherapy with cycloserine (CS), ethionamide (TH), kanamycin (KM), pyrazinamide (PZA), para-aminosalicylic acid (PAS) and gatifloxacin (GFLX). Two months later, psychosis and seizure occurred and worsened day after day. We suspected that these symptoms were due to CS. After stopping CS, psychosis and seizure disappeared. After surgical operation, positive tubercle bacilli in sputum converted to negative both on smear and culture. He was successfully discharged from our hospital. We should take care on side effects with second-line drugs that are often used in treating multi-drug resistant tuberculosis.

[69 years old male patient, with impairment of physical condition, hyperpigmentation, cutaneous lesion and a deficient response to treatment]

We submit the case of a male patient, suffering from a tuberculous ethiology adrenal primary insufficiency, showing a dermal lesion, in which necrotizing granulomas were found, and from which bacterial culture growth yielded mycobacterium bovis. Given the clinical findings, and awaiting for the bacterial culture result, a triple treatment with tuberculostatics was started, but had to be discontinued because of hepatic toxicity. After culture of cutaneous biopsy yielded micobaterium tuberculosis, treatment with streptomycin, rifampicin and etambutol was restarted. Three weeks later, in spite of increasing hydrocortisone dose to 40 mg, adrenal insufficiency reappeared. Under the circumstances, we chose to continue rifampicin and double hydrocortisone dose. The case is of concern because of the concurrency of three nowadays infrequent disorders: tuberculous ethiology adrenal insufficiency, cutaneous tuberculosis due to mycobacterium bovis and primary adrenal insufficiency due to rifampicin treatment, the latter resolved after increasing hydrocortisone dose.

Rifabutin for treating pulmonary tuberculosis

BACKGROUND

Rifamycins are an essential component of modern short-course regimens for treating tuberculosis. Rifabutin has favourable pharmacokinetic and pharmacodynamic properties and is less prone to drug-drug interactions than rifampicin. It could contribute to shortening of therapy or simplify treatment in HIV-positive people who also need antiretroviral drugs.

OBJECTIVES

To compare combination drug regimens containing rifabutin with those containing rifampicin for treating pulmonary tuberculosis

SEARCH STRATEGY

We searched Cochrane Infectious Diseases Group Specialized Register (January 2007), CENTRAL (The Cochrane Library 2006, Issue 4), MEDLINE (1966 to January 2007), EMBASE (1974 to January 2007), and LILACS (1982 to January 2007). We also searched the Indian Journal of Tuberculosis (1983 to 2006), conference abstracts, reference lists, and unpublished data on file at Pfizer Inc.

SELECTION CRITERIA

Randomized and quasi-randomized trials including participants with sputum smear and/or culture-confirmed tuberculosis that compared a rifabutin-containing with an otherwise identical rifampicin-containing regimen.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and methodological quality, and extracted data. Dichotomous data were analysed and combined using relative risks (RR) with 95% confidence intervals (CI) using a fixed-effect model. Subgroup analyses were carried out according to rifabutin dose.

MAIN RESULTS

Five trials with a total of 924 participants met the inclusion criteria; 5% of participants were HIV positive. Only one small trial was methodologically adequate. The two largest trials (818 participants) had unclear allocation concealment and included < 90% of randomized participants in the analysis. There was no statistically significant difference in between the regimens for cure (RR 1.00, 95% CI 0.96 to 1.04; 553 participants, 2 trials) or relapse (RR 1.23, 95% CI 0.45 to 3.35; 448 participants, 2 trials). The number of adverse events was not significantly different (RR 1.42, 95% CI 0.88 to 2.31; 714 participants, 3 trials), though the RR increased with rifabutin dose: 150 mg (RR 0.98, 95% CI 0.45 to 2.12; 264 participants, 2 trials); and 300 mg (RR 1.78, 95% CI 0.94 to 3.34; 450 participants, 2 trials). However, lack of dose adjustment by weight in the relevant trials complicates interpretation of this relationship.

AUTHORS' CONCLUSIONS

The replacement of rifampicin by rifabutin for first-line treatment of tuberculosis is not supported by the current evidence. HIV-positive people with tuberculosis, the group most likely to benefit from the rifabutin use, are under-represented in trials to date, and further trials in this group would be useful.

Rifampin-induced hypothyroidism without underlying thyroid disease

Rifampin (RFP) increases hepatic microsomal enzyme activity, and there are case reports of RFP-induced hypothyroidism, all associated with Hashimoto's thyroiditis. Here, we report a case of RFP-induced hypothyroidism without underlying thyroid disease.

Clinical characteristics of tuberculosis in patients with liver cirrhosis

BACKGROUND AND OBJECTIVES

Patients with liver cirrhosis are likely to be susceptible to tuberculosis (TB) because of immune system dysfunction. The aim of this study was to elucidate the clinical characteristics and treatment responses in TB patients with cirrhosis.

METHODS

Cases were patients with TB detected during their follow up for liver cirrhosis over a 4-year period. Controls were randomly selected patients with TB but no liver disease, matched to cases by age and gender in a 3:1 ratio.

RESULTS

Thirty-six cases and 108 controls were enrolled. Extrapulmonary TB was more common in cases than controls (31% vs 12%, P = 0.02). Clinical and radiographic manifestations and response to treatment did not differ between the two groups. The frequency of hepatotoxicity was higher in the cases than in the controls who were treated with a regimen containing rifampicin and isoniazid, although the difference was not statistically significant (27% vs 10%, P = 0.079).

CONCLUSIONS

TB patients with liver cirrhosis show extrapulmonary involvement more frequently. Patients with pulmonary TB and cirrhosis usually respond well to anti-TB treatment although appear to present more frequently with treatment-related hepatotoxicity.

Rifampin, a cytochrome P450 3A inducer, decreases plasma concentrations of antipsychotic risperidone in healthy volunteers

BACKGROUND

Although cytochrome P450 (CYP) 2D6 is often thought to be the only CYP responsible for the metabolism of risperidone, many reports suggest that CYP3A may be involved too. Rifampin, a potent CYP3A inducer, has been known to markedly decrease plasma concentrations of various drugs, which are concomitantly administered during treatment.

OBJECTIVE

To examine the effect of rifampin on plasma concentrations of a single oral dose of risperidone in healthy Thai male volunteers.

METHODS

In an open, randomized two-phase crossover study, separated by a 2-week period, 10 healthy Thai male volunteers received a single oral dose of 4-mg risperidone alone or with 600 mg rifampin, orally once daily for 5 days. Serial blood samples were collected at specific time points for a 48-h period. Risperidone was measured in plasma using high performance liquid chromatography with ultraviolet detection. Pharmacokinetic parameters were determined by using non-compartmental analysis.

RESULTS

Co-administration with 600-mg rifampin once daily for 5 days was associated with a significant decrease in risperidone area under the curve (AUC(0-48)) and maximal concentration (C(max)) by 72% (157 x 49 +/- 48 x 80 vs. 42 x 66 +/- 7 x 81 ng/L/h; P<0 x 01) and 50% (32 x 44 +/- 6 x 05 vs. 16 x 16 +/- 2 x 73 ng/mL; P<0 x 05), respectively when compared with risperidone alone.

CONCLUSIONS

Rifampin when used concurrently with risperidone significantly decreases the plasma concentration of risperidone. Our results provide in vivo evidence of the involvement of CYP3A in the metabolism of risperidone, in addition to CYP2D6. Thus, co-administration of risperidone with CYP3A inducer(s), including rifampin should be recognized or avoided in clinical practice.

Update on the interaction of rifampin and warfarin

A 79-year-old man with a history of deep vein thrombosis and pulmonary embolism received anticoagulation therapy with warfarin 5 mg daily for 8 months. He was diagnosed with osteomyelitis and underwent partial metatarsal resection of his right foot. After surgery, antibiotics were initiated, including ertapenem sodium 1 g intravenously every 24 hours, vancomycin 1400 mg intravenously every 24 hours, and rifampin 300 mg by mouth twice daily. Achieving a therapeutic level of anticoagulation was difficult despite escalating doses of warfarin, because of the interaction with rifampin. A 5- to 6-fold increase in warfarin dose was prescribed to reach therapeutic international normalized ratios (INRs), but even these increases were insufficient to maintain his INR in the therapeutic range. After rifampin was discontinued, warfarin doses were gradually reduced over the next 2 months. When concurrent warfarin-rifampin therapy is necessary, vigilant monitoring is imperative and significant increases in warfarin doses are likely.

Rifampicin-associated segmental necrotizing glomerulonephritis in staphylococcal endocarditis

Segmental necrotising glomerulonephritis has been reported as complication of rifampicin therapy in patients receiving treatment for tuberculosis. Changing epidemiology of infections such as infective endocarditis (IE) has led to an increase in the use of rifampicin for Staphylococcal infections. We describe a case of a patient with Staphylococcal IE who developed acute renal failure secondary to a segmental necrotising glomerulonephritis while being treated with rifampicin, and review the literature regarding this complication of rifampicin therapy.

Clinical Evaluation of the Nelfinavir-Rifabutin Interaction in Patients with Tuberculosis and Human Immunodeficiency Virus Infection

STUDY OBJECTIVE

To characterize the bidirectional interaction between twice-daily nelfinavir and twice-weekly rifabutin and isoniazid in patients with tuberculosis and human immunodeficiency virus (HIV) infection.

DESIGN

Prospective cohort study.

SETTING

Three clinical research centers.

PATIENTS

Seven patients with HIV-related tuberculosis.

INTERVENTION

Rifabutin 300 mg and isoniazid 15 mg/kg (maximum dose 900 mg) twice/week were administered for at least 2 weeks during the continuation phase of tuberculosis treatment. Antiretroviral therapy with nelfinavir 1250 mg twice/day and two nucleoside reverse transcriptase inhibitors was then added.

MEASUREMENTS AND MAIN RESULTS

Patients underwent blood sampling for pharmacokinetic analysis during the continuation phase of tuberculosis therapy and after a median of 21 days after the addition of antiretroviral treatment. When rifabutin was coadministered with nelfinavir, its area under the concentration-time curve from 0-21 hours (AUC(0-21)) increased 22% (geometric mean 5.01 microg.hr/ml [90% confidence interval (CI) 3.25-7.71] with nelfinavir vs 4.10 microg.hr/ml [90% CI 3.18-5.27] without nelfinavir; geometric mean ratio 1.22 [90% CI 0.78-1.92]). Also, the AUC(0-21) for the active metabolite, desacetylrifabutin, increased significantly (geometric mean ratio 3.46, 90% CI 1.84-6.47, p=0.009). In the presence of rifabutin, the pharmacokinetic parameters of nelfinavir and its principal metabolite M8 were similar to those of patients not taking rifabutin. No drug interaction between nelfinavir and isoniazid was detected.

CONCLUSIONS

Coadministration of rifabutin and isoniazid without dosage adjustment during twice-weekly tuberculosis therapy with nelfinavir-based antiretroviral therapy resulted in rifabutin exposures within the acceptable ranges for safety and efficacy. Therefore, this combination is an appropriate option for the simultaneous treatment of tuberculosis and HIV infection when tuberculosis therapy is given twice weekly.

Pharmacokinetics and tolerability of a higher rifampin dose versus the standard dose in pulmonary tuberculosis patients

Rifampin is a key drug for tuberculosis (TB) treatment. The available data suggest that the currently applied 10-mg/kg of body weight dose of rifampin may be too low and that increasing the dose may shorten the treatment duration. A double-blind randomized phase II clinical trial was performed to investigate the effect of a higher dose of rifampin in terms of pharmacokinetics and tolerability. Fifty newly diagnosed adult Indonesian TB patients were randomized to receive a standard (450-mg, i.e., 10-mg/kg in Indonesian patients) or higher (600-mg) dose of rifampin in addition to other TB drugs. A full pharmacokinetic curve for rifampin, pyrazinamide, and ethambutol was recorded after 6 weeks of daily TB treatment. Tolerability was assessed during the 6-month treatment period. The geometric means of exposure to rifampin (area under the concentration-time curve from 0 to 24 h [AUC(0-24)]) were increased by 65% (P < 0.001) in the higher-dose group (79.7 mg.h/liter) compared to the standard-dose group (48.5 mg.h/liter). Maximum rifampin concentrations (C(max)) were 15.6 mg/liter versus 10.5 mg/liter (49% increase; P < 0.001). The percentage of patients for whom the rifampin C(max) was > or =8 mg/liter was 96% versus 79% (P = 0.094). The pharmacokinetics of pyrazinamide and ethambutol were similar in both groups. Mild (grade 1 or 2) hepatotoxicity was more common in the higher-dose group (46 versus 20%; P = 0.054), but no patient developed severe hepatotoxicity. Increasing the rifampin dose was associated with a more than dose-proportional increase in the mean AUC(0-24) and C(max) of rifampin without affecting the incidence of serious adverse effects. Follow-up studies are warranted to assess whether high-dose rifampin may enable shortening of TB treatment.

Rifampicin induced thrombocytopenia

Thrombocytopenia is an uncommon but potentially life threatening complication of certain anti-tubercular drugs and is characterized by rapid destruction of platelets whenever an offending drug is taken by a susceptible person. Here is a case report of Rifampicin induced Thrombocytopenia. This case is being reported for purpose of its rare occurrence and documentation.

Rifabutin-induced hypopyon uveitis in patients with acquired immunodeficiency syndrome infected with Mycobacterium avium complex

Rifabutin is a semi-synthetic antimycobacterial agent mainly used in the prophylaxis and treatment of Mycobacterium avium complex (MAC) in acquired immunodeficiency syndrome patients. Uveitis as a side effect of rifabutin has been recognized and established since 1994, but there was no case previously described in Taiwan so far. We report 2 cases of rifabutin-induced hypopyon uveitis in patients with human immunodeficiency virus and MAC infection. Both patients received the regimen of clarithromycin and rifabutin to treat MAC infection. Uveitis resolved after discontinuing of rifabutin and treatment with topical corticosteroid and mydriatics. Early recognition of this entity can prevent invasive ocular procedures and treatments. Doctors who prescribe rifabutin should be aware of this ocular complication of uveitis and drug-drug interactions. Ophthalmologists should put this on the list of differential diagnoses for uveitis.

Clinical aspects of rifampicin-associated pseudomembranous colitis

Pseudomembranous colitis (PMC) is known to develop after antibiotic administration, but antituberculosis agents are rarely associated with this disorder. We report 6 cases of PMC after rifampicin administration; the clinical manifestations, laboratory findings, imaging findings, and clinical course are described. The median age of patients was 68 years (range, 54 to 82 y). All patients were diagnosed with active pulmonary tuberculosis by sputum smear and culture, and 2 suffered from type 2 diabetes mellitus. The average interval between initiation of antituberculosis therapy and the onset of diarrhea was 19.8 days. The anatomic distribution of PMC included the rectum and sigmoid colon in 5 cases and up to the hepatic flexure in 1 case. All patients were cured with medical treatment, which include discontinuation of rifampicin and oral metronidazole and vancomycin. PMC recurred in 1 patient after retreatment with rifampicin. Our findings suggest that patients who are treated with antituberculosis agents, who develop acute diarrhea during or after therapy, should be evaluated for PMC.