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Mycobutin (Rifabutin) - Summary

 
 



MYCOBUTIN SUMMARY

Mycobutin®
rifabutin capsules, USP

MYCOBUTIN Capsules contain the antimycobacterial agent rifabutin, which is a semisynthetic ansamycin antibiotic derived from rifamycin S.

MYCOBUTIN Capsules are indicated for the prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.


See all Mycobutin indications & dosage >>

NEWS HIGHLIGHTS

Published Studies Related to Mycobutin (Rifabutin)

Determination of rifabutin dosing regimen when administered in combination with ritonavir-boosted atazanavir. [2011.09]
OBJECTIVES: Treatment of HIV/tuberculosis (TB) co-infected patients is complex due to drug-drug interactions for these chronic diseases. This study evaluates an intermittent dosing regimen for rifabutin when it is co-administered with ritonavir-boosted atazanavir... CONCLUSIONS: The benefits to HIV/TB co-infected patients receiving rifabutin 150 mg three times weekly or every other day may outweigh the risks of neutropenia observed here in non-HIV-infected subjects, provided that patients on combination therapy will be closely monitored for safety and tolerability.

Efficacy of rifabutin-based triple therapy as second-line treatment to eradicate helicobacter pylori infection. [2007.07.25]
BACKGROUND: Rifabutin has been found to be effective in multi-resistant patients after various treatment cycles for Helicobacter pylori (HP) infection, but it has not been analysed as a second-line treatment. Therefore, we seek to compare the effectiveness of a treatment regimen including rifabutin versus conventional quadruple therapy (QT)... CONCLUSION: A 7-day rifabutin-based triple therapy associated to amoxicillin and omeprazole at standard dose was not found to be effective as a second-line rescue therapy. The problem with quadruple therapy lies in the adverse side effects it provokes. We believe the search should continue for alternatives that are more comfortably administered and that are at least as effective, but with fewer adverse side effects. TRIAL REGISTRATION: Current Controlled Trials ISRCTN81058036.

Two-year combination antibiotic therapy with clarithromycin, rifabutin, and clofazimine for Crohn's disease. [2007.06]
BACKGROUND & AIMS: Mycobacterium avium subspecies paratuberculosis has been proposed as a cause of Crohn's disease. We report a prospective, parallel, placebo-controlled, double-blind, randomized trial of 2 years of clarithromycin, rifabutin, and clofazimine in active Crohn's disease, with a further year of follow-up... CONCLUSIONS: Using combination antibiotic therapy with clarithromycin, rifabutin, and clofazimine for up to 2 years, we did not find evidence of a sustained benefit. This finding does not support a significant role for Mycobacterium avium subspecies paratuberculosis in the pathogenesis of Crohn's disease in the majority of patients. Short-term improvement was seen when this combination was added to corticosteroids, most likely because of nonspecific antibacterial effects.

Randomized trial of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin. [2006.07.15]
BACKGROUND: The clinical management of Helicobacter pylori infected patients who failed standard eradication therapies remains a challenge. AIM: To investigate the efficacy of rifabutin-based triple therapy and high-dose dual therapy for rescue treatment of H. pylori, and the correlation between cytochrome P450 2C19 (CYP2C19) polymorphisms and treatment outcome... CONCLUSIONS: Triple therapy with esomeprazole, rifabutin and amoxicillin and high-dose omeprazole/amoxicillin are comparable and effective and safe for rescue therapy of H. pylori regardless of the patient's CYP2C19 genotype.

[Three cases of uveitis induced by mycobacteriosis therapy using rifabutin]. [2011.07]
CONCLUSION: Rifabutin rarely causes uveitis as an ocular side effect. Early diagnosis and is important and reduction or discontinuance of the rifabutin as well as anti-inflammatory therapy need to be implemented when a patient develops this condition.

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Clinical Trials Related to Mycobutin (Rifabutin)

EARNEST Rifabutin Pharmacokinetics (PK) Substudy [Recruiting]

- Background and study aims?

Some of the drugs used to treat HIV (anti-retrovirals, or ARVs) can affect the blood levels

of other drugs used to treat TB - called a "drug-drug interaction". The main drug used in

second-line therapy, Aluvia (lopinavir/ritonavir), is one of the drugs that has this effect. This is why people on second-line ARVs usually cannot use one of the main TB drugs, "rifampicin", and instead will be prescribed a slightly different drug called "rifabutin", which is less affected by these drug-drug interactions. Although blood levels of rifabutin are not as badly affected by Aluvia as blood levels of rifampicin, rifabutin levels in the blood are still increased a lot by taking Aluvia at the same time. This could lead to higher levels of side-effects because there is more drug in the body. So in the past doctors have suggested that instead of taking rifabutin every day with Aluvia, it should only be taken three times a week, on Mondays, Wednesdays and Fridays. However, in the last 2 years, new studies have suggested that this three times a week regimen might not be enough and that it may not completely cure TB. So the purpose of this study is to find out whether taking rifabutin every day with Aluvia really does lead to more side-effects, and whether taking rifabutin three times a week with Aluvia really does lead to much lower levels of rifabutin in the blood.

- Who can participate?

This substudy is specifically for people who are already taking anti-TB drugs in EARNEST, or who need to start anti-TB drugs whilst they are in the EARNEST trial.

- What does the study involve?

Participants will be selected (by chance, chosen by a computer) to one of the following two rifabutin groups:

Group 1: Rifabutin (150 mg) taken three times a week on Monday/Wednesday/Friday Group 2: Rifabutin (150 mg) taken every day On these days, one capsule of rifabutin (150 mg) should be taken in the morning by mouth.

Participants will be asked to attend clinic 2 and 12 weeks after entering the sub-study then every 6 weeks until the end of their TB treatment, and then return to their usual EARNEST follow-up schedule. This is roughly the same visit schedule for people with TB who are usually seen more frequently than those without TB, whether or not the patients join this sub-study. The 2 week visit is specifically so the investigators can make sure participants are doing OK on rifabutin and to check carefully that they don't have any side-effects. At all these visits (including the day when participants enroll into the substudy) the investigators will take an extra 10 ml (two teaspoons) of blood to do laboratory tests for side-effects of rifabutin, and to measure the levels of rifabutin and other ARVs in the

blood - these are called "pharmacokinetic" or "PK" studies. On the day of these visits,

participants should not take their dose of rifabutin until after this blood draw, so the investigators can measure the lowest amount of drug likely in their blood. Instead, participants should bring the rifabutin dose to clinic, so that they can take it straight after the blood draw. At the visit 12 weeks after starting rifabutin, participants will need to stay in clinic for a second blood draw of ~3 ml (half a teaspoon) around 4 hours after they take the rifabutin dose immediately after the first blood draw. We use this second sample to see how quickly rifabutin enters the blood. At this special visit the investigators will make sure participants are first seen as early as possible, so they don't have to stay any longer than necessary for the second blood draw to be taken 4 hours later. After participants have completed their TB treatment they will stay in EARNEST until the end of the trial (144 weeks on second-line therapy).

- What are the possible benefits and risks of participating?

If participants are allocated to Group 1 (150 mg rifabutin three times a week), there is a risk that they may have lower levels of rifabutin in your blood and this may be less effective at treating the TB. However, participants should have fewer side-effects. In contrast, if participants are allocated to Group 2 (150 mg rifabutin daily), here is a risk that they may get more side-effects, but the levels of rifabutin in the blood should be more than high enough to have a good chance of curing the TB. Having blood taken may cause some discomfort and/or bruising in some people. It is currently impossible to know which rifabutin regimen would be best and participants may find in years to come that they may or may not have received the best treatment.

- Where is the study run from?

9 EARNEST sites in Uganda as follows: JCRC Kampala, IDI, San Raphael of St Francis Hospital (Nsambya), JCRC Mbarara, JCRC Mbale, JCRC Kabale, JCRC Kakira, JCRC Gulu

- When is study starting and how long is it expected to run?

Start 05/03/2012 finish on 31/01/2014

- Who is funding the study? Abbott

Pharmacokinetics of Rifabutin Combined With Antiretroviral Therapy in Patients With TB/HIV Co-infection in South Africa [Recruiting]
The overall aim of the project is to evaluate rifabutin (RBT) as a replacement for rifampicin (RMP), for the combined treatment of tuberculosis and HIV infection. RBT represents an alternative to RMP for HIV infected patients as its half-life is longer and the enzymatic induction effect appears to be less important on the associated antiretroviral therapy (ART) drugs.

This phase II trial is to determine precisely the pharmacokinetics parameters of RBT in combination with different ART regimens in Vietnamese HIV infected patients with pulmonary tuberculosis, in order to define optimal doses that will be further tested in a larger phase III trial comparing safety, tolerability and efficacy of RBT and RMP regimens.

TBTC Study 23B:Intensive PK of the Nelfinavir Rifabutin Interaction in Patients With HIV-TB [Completed]
Primary Objective:

To define the impact of nelfinavir (given at 1250mg bid as part of a combination antiretroviral regimen) on peak levels and area under the curve for rifabutin and the rifabutin metabolite, 25-O-desacetyl rifabutin when rifabutin is given at 300 mg bi-weekly as part of tuberculosis chemotherapy.

Secondary Objectives:

To compare the pharmacokinetics of nelfinavir given twice daily at 1250 mg bid with twice-weekly isoniazid and rifabutin to the pharmacokinetics of nelfinavir 1250 mg twice-daily in historical HIV-infected patients not receiving isoniazid and rifabutin.

To evaluate the correlation between pharmacokinetic parameters of rifabutin and 25-O-desacetyl rifabutin and the occurrence of toxicity attributed to rifabutin in patients with HIV-related tuberculosis.

To define detailed pharmacokinetics of isoniazid given at 15mg/kg or 900 mg in patients with HIV-related tuberculosis.

To attempt to derive optimal sampling times for nelfinavir and rifabutin pharmacokinetic studies.

Pharmacokinetics of Rifabutin Combined With Antiretroviral Therapy in Patients With TB/HIV Co-infection in Vietnam [Recruiting]
The overall aim of the project is to evaluate rifabutin (RBT) as a replacement for rifampicin (RMP), for the combined treatment of tuberculosis and HIV infection. RBT represents an alternative to RMP for HIV infected patients as its half-life is longer and the enzymatic induction effect appears to be less important on the associated antiretroviral therapy (ART) drugs.

This phase II trial is to determine precisely the pharmacokinetics parameters of RBT in combination with different ART regimens in Vietnamese HIV infected patients with pulmonary tuberculosis, in order to define optimal doses that will be further tested in a larger phase III trial comparing safety, tolerability and efficacy of RBT and RMP regimens.

TBTC Study 23A: Pharmacokinetics of Intermittent Isoniazid and Rifabutin in HIV-TB [Completed]
Primary Objectives:

1) To determine the proportion of patients with HIV-related tuberculosis who have abnormal pharmacokinetic parameters for isoniazid and rifabutin.

Secondary Objectives:

1. To determine risk factors for abnormal pharmacokinetic parameters for isoniazid and rifabutin.

2. To evaluate the correlation between pharmacokinetic parameters of isoniazid and rifabutin and the occurrence of toxicity attributed to antituberculous therapy.

3. To evaluate the correlation between pharmacokinetic parameters of isoniazid and rifabutin and the efficacy of TB therapy.

4. To define and correlate phenotypic INH acetylator status with the results of genotypic acetylator data obtained in the parent trial.

more trials >>

Reports of Suspected Mycobutin (Rifabutin) Side Effects

Pyrexia (7)Mycobacterium Avium Complex Infection (5)Cytomegalovirus Chorioretinitis (5)Immune Reconstitution Syndrome (4)Headache (4)Bone Marrow Disorder (4)Thrombocytopenia (4)Visual Impairment (4)Leukopenia (4)Drug Eruption (3)more >>


Page last updated: 2011-12-09

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