L-30 : Antimycobacterial Agents Mycobacteria and Tuberculosis Quiz

Drug-resistant tuberculosis (DR-TB) is a form of tuberculosis that does not respond to standard first-line and second-line treatments.

Treatment options for DR-TB are often less effective and have more side effects than standard TB treatments.

DOT (Directly Observed Therapy) involves healthcare professionals directly observing patients taking their medication to ensure adherence.

DOT is considered a core management strategy for all tuberculosis patients.

First-line drugs (FLDs) are the primary medications used to treat TB.

Second-line drugs (SLDs) are used when TB does not respond to first-line drugs or when the patient has specific conditions.

Isoniazid (INH), Rifampin, Ethambutol, and Pyrazinamide are examples of first-line drugs commonly used to treat TB.

Amikacin, Ciprofloxacin, Ethionamide, and Streptomycin are examples of second-line drugs used to treat TB.

Streptomycin is now considered a second-line drug in many parts of the world because of increasing resistance and side effects.

Mycobacteria are bacteria that are able to retain the carbolfuchsin stain even after washing with acid-alcohol. This characteristic is due to the high lipid content (60%) in their cell walls, particularly the long-chain fatty acid (C70 to C90) called mycolic acid.

Multidrug-resistant TB (MDR TB) is a type of TB that is resistant to at least two of the most effective TB drugs, isoniazid and rifampicin. These are considered first-line drugs for treating all TB cases.

Extensively drug-resistant TB (XDR TB) is a rare form of MDR TB. In addition to being resistant to isoniazid and rifampicin, XDR TB is also resistant to fluoroquinolones and at least one of the three injectable second-line drugs (amikacin, kanamycin, or capreomycin).

Mycobacteria are obligate aerobes, meaning they require oxygen for survival and growth. This is why infections often occur in highly oxygenated areas.

M. tuberculosis is the causative agent of tuberculosis, while M. leprae is responsible for leprosy.

Mycobacteria can be grown in special media like Lowenstein-Jensen, which includes malachite green to inhibit the growth of other bacteria. However, M. leprae cannot be grown in any currently available bacteriologic media.

The transition from MDR TB to XDR TB, which is resistant to even more drugs, is a challenging aspect of TB treatment. This shift often occurs due to the misuse of first-line and second-line drugs.

This drug is used in short-term TB treatment regimens and is effective against Mycobacterium tuberculosis. It's well-absorbed orally and can reach the brain. However, it can cause serious liver problems.

These drugs are used to treat TB when the bacteria are resistant to first-line medications. They are often given in combination and can have serious side effects.

These drugs are used to treat Hansen's disease, also known as leprosy. Dapsone and clofazimine are commonly used.

This is a side effect of some TB medications that can cause joint pain and discomfort.

Isoniazid is a drug used to treat tuberculosis. It works by killing the bacteria that causes TB. It can cause liver damage and nerve damage, but these side effects can be reduced by taking vitamin B6.

Rifampin is another drug used for tuberculosis. It blocks the bacteria's RNA synthesis, preventing them from making essential proteins. It is often used in combination with other drugs.

Isoniazid can cause liver damage, which may be more severe in older adults. This side effect is known as hepatotoxicity.

Isoniazid can also cause nerve damage, known as peripheral neuropathy. This is rare but can occur in a small number of patients.

Vitamin B6 (pyridoxine) can help reduce the risk of nerve damage caused by isoniazid.

Rifampin can cause a red-orange color in urine, saliva, and body fluids. This can be used to check if a patient is taking their medication.

Rifampin is well-tolerated by most people. The most common side effect is stomach upset, but it can also cause liver problems in older adults and alcohol users.

Rifampin can increase the risk of liver damage when taken with isoniazid.

Rifampin can interact with other medications and affect how they are processed by the body.

Rifampin can cause skin rashes, low platelet count, and other rare side effects.

Rifampin is an antibiotic used in TB treatment but interacts negatively with protease inhibitors. PIs reduce Rifampin's effectiveness and Rifampin increases PIs' side effects like liver and gastrointestinal toxicity.

Rifapentine is a second-line TB drug with a longer half-life than Rifampin, but also interacts negatively with protease inhibitors.

Rifabutin is a rifamycin derivative used for patients who cannot tolerate Rifampin. It's also effective against mycobacteria that resist Rifampin.

Ethambutol is a bacteriostatic drug that blocks the synthesis of a component in the mycobacterial cell wall. It is used primarily in combination with other TB drugs.

Ethambutol is primarily administered orally and is eliminated in the urine. It penetrates well into the central nervous system (CNS).

Ethambutol can cause visual disturbances, including green blindness, retinal damage, and even headache and confusion.

Pyrazinamide is a bactericidal drug that is converted into an active form (pyrazinoic acid) by an enzyme within the Mycobacterium tuberculosis bacterium.

Pyrazinamide is effective primarily against Mycobacterium tuberculosis and has a narrow spectrum of activity. It is similar to isoniazid in terms of targeting TB bacteria.

Directly Observed Therapy (DOT) ensures patients take their medication as prescribed by involving healthcare professionals in the medication-taking process.

First-line drugs are the initial medications used to treat TB. They are recommended for most patients and are typically more effective and have fewer side effects.