ATD in TB refers to Anti-Tuberculosis Drugs, medications used to treat Tuberculosis.
Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. Treating TB requires a prolonged course of antibiotics, often involving a combination of several different drugs to prevent drug resistance and effectively eradicate the bacteria. These drugs are collectively known as Anti-Tuberculosis Drugs (ATDs).
Common Anti-Tuberculosis Drugs (ATDs)
The most common first-line anti-TB drugs include:
- Isoniazid (INH): A cornerstone of TB treatment.
- Rifampin (RIF): Another essential drug with broad antibacterial activity.
- Ethambutol (EMB): Used to prevent resistance to other drugs.
- Pyrazinamide (PZA): Helps to shorten the duration of treatment.
- Streptomycin (SM): An injectable aminoglycoside, less commonly used as a first-line drug due to the availability of oral options.
These drugs are often given in combination during the initial phase of treatment (usually 2 months), followed by a continuation phase (usually 4 months) with fewer drugs.
Importance of Adherence to ATD Therapy
Adherence to the prescribed ATD regimen is crucial for several reasons:
- Eradication of the bacteria: Consistent drug levels are needed to kill all TB bacteria.
- Prevention of drug resistance: Irregular or incomplete treatment can lead to the development of drug-resistant TB strains.
- Successful treatment outcomes: Proper adherence significantly improves the chances of a complete cure and prevents relapse.
Adverse Effects of ATDs
Anti-tuberculosis drugs, while effective, can cause adverse effects. Some of these can be severe. For example, some ATDs can lead to severe cutaneous adverse reactions (SCARs) such as:
- Stevens-Johnson syndrome (SJS)
- Toxic epidermal necrolysis (TEN)
- Drug reaction with eosinophilia and systemic symptoms (DRESS).
Other common side effects include liver toxicity, gastrointestinal disturbances, and neurological symptoms. Regular monitoring and prompt management of any adverse effects are essential during TB treatment.
Second-Line Anti-Tuberculosis Drugs
When TB strains become resistant to first-line drugs (Multi-Drug Resistant TB or MDR-TB), second-line anti-TB drugs are used. These drugs are generally more toxic and require longer treatment durations. Examples of second-line ATDs include:
- Fluoroquinolones (e.g., moxifloxacin, levofloxacin)
- Aminoglycosides (e.g., amikacin, kanamycin)
- Capreomycin
- Ethionamide
- Cycloserine
- Para-aminosalicylic acid (PAS)
