Drug Therapy of Tuberculosis

Questions and Answers

What is the primary objective of tuberculosis treatment?

Prevent disease transmission (correct)

Eliminate all symptoms immediately

Achieve a persistent immune response

Introduce new strains of bacteria

Which of the following drugs is classified as a first line antituberculosis drug?

Moxifloxacin

Isoniazid (correct)

Azithromycin

Ciprofloxacin

What characterizes multidrug-resistant tuberculosis?

Resistance to isoniazid and rifampin (correct)

Only responsive to first-line drugs

Highly contagious strain only

Resistance to all known antibiotics

What does Directly Observed Treatment, Short-Course (DOTS) help ensure?

All doses are taken appropriately Signup and view all the answers

What is commonly a rationale for combination antimicrobial therapy in tuberculosis treatment?

To prevent the development of resistance Signup and view all the answers

What is true about latent tuberculosis infection?

It can be treated with first-line drugs Signup and view all the answers

What is an important aspect of the pharmacokinetics of first-line antituberculosis drugs?

Their absorption rates vary among patients Signup and view all the answers

Which of the following is NOT a major effect of first-line antituberculosis drugs?

Permanent skin changes Signup and view all the answers

What defines extensively drug-resistant tuberculosis?

Resistance to first line drugs, a fluoroquinolone, and aminoglycoside. Signup and view all the answers

What does DOTS refer to in tuberculosis management?

Directly observed treatment, short-course. Signup and view all the answers

How is tuberculosis primarily transmitted?

By inhalation. Signup and view all the answers

What is the primary treatment approach for active tuberculosis?

Combination therapy with multiple drugs. Signup and view all the answers

What is considered as prophylactic treatment for latent tuberculosis?

Monotherapy using one drug. Signup and view all the answers

Which bacterium is primarily responsible for tuberculosis?

Mycobacterium tuberculosis. Signup and view all the answers

What is one of the general therapeutic objectives in treating pulmonary tuberculosis?

Decrease transmission of TB. Signup and view all the answers

Which of the following is NOT a form of drug action in tuberculosis treatment?

Molecular therapy. Signup and view all the answers

What is the primary site of action for isoniazid?

Synthesis of mycolic acids Signup and view all the answers

What is the mechanism of action (MoA) of isoniazid?

Inhibits synthesis of mycolic acids Signup and view all the answers

Which of the following is a therapeutic use of isoniazid?

Treatment of latent tuberculosis infection Signup and view all the answers

What is a significant adverse effect of isoniazid?

Hepatotoxicity Signup and view all the answers

How does isoniazid exhibit its bactericidal activity?

By disrupting cell wall synthesis Signup and view all the answers

Which other first-line anti-tuberculosis drug is commonly used alongside isoniazid?

Rifampin Signup and view all the answers

Which statement best describes isoniazid's activity against other mycobacteria?

Less active against other mycobacteria Signup and view all the answers

What gastrointestinal side effect is associated with isoniazid use?

Gastrointestinal upset Signup and view all the answers

What effect does isoniazid have on acetaminophen?

It enhances the hepatotoxic effect of acetaminophen. Signup and view all the answers

Which is a mechanism of action for rifampin?

Blocking RNA production. Signup and view all the answers

What is a common side effect of rifampin?

Rash. Signup and view all the answers

Which condition can arise from phenytoin being used with isoniazid?

Increased effects of phenytoin. Signup and view all the answers

What type of infections is rifampin primarily used to treat?

Atypical mycobacterial infections. Signup and view all the answers

What can happen if rifampin is used as a single drug?

Resistance may rapidly emerge. Signup and view all the answers

Which of the following is NOT a side effect of rifampin?

Weight gain. Signup and view all the answers

What is the primary action of rifampin on mycobacteria?

It exhibits bactericidal activity. Signup and view all the answers

What side effects are specifically noted as dose-related for isoniazid?

Neuropathy, ataxia, and paresthesia Signup and view all the answers

What is the suggested preventative measure for the neurologic side effects caused by isoniazid?

Administration of pyridoxine Signup and view all the answers

Which condition indicates significant hepatotoxicity in a patient taking isoniazid?

Transaminases exceeding five times the upper limit of normal Signup and view all the answers

What is a potential interaction that reduces the absorption of isoniazid?

Administration with food Signup and view all the answers

What metabolic process affects the pharmacokinetics of isoniazid?

Hepatic first-pass metabolism Signup and view all the answers

Which metabolite of isoniazid is associated with hepatotoxicity?

Hydroxylated monoacetylhydrazine Signup and view all the answers

What genetic factor influences the metabolism of isoniazid?

Slow and fast acetylators Signup and view all the answers

What symptom is NOT associated with INH-induced hepatotoxicity?

Substantial weight gain Signup and view all the answers

Study Notes

Therapeutic Objectives of Tuberculosis Treatment

Aim to reduce transmission of tuberculosis (TB) among the population.
Decrease morbidity and mortality associated with active TB.
Facilitate rapid recovery and restoration of health in affected individuals.

Classification of Anti-TB Drugs

First-line drugs include:
- Isoniazid
- Rifampin
- Pyrazinamide
- Ethambutol
Multidrug-resistant tuberculosis (MDR-TB) occurs when strains resist at least isoniazid and rifampin.
Extensively drug-resistant tuberculosis (XDR-TB) shows resistance to isoniazid, rifampin, a fluoroquinolone, and an aminoglycoside.

Mechanism of Action and Pharmacokinetics of First-Line Antituberculosis Drugs

Isoniazid:
- Inhibits synthesis of mycolic acids essential for mycobacterial cell walls.
- Display bactericidal activity against susceptible M. tuberculosis strains.
- Can cause hepatotoxicity, gastrointestinal upset, and neurologic side effects.
Rifampin:
- Inhibits DNA-dependent RNA polymerase, blocking RNA production.
- Exhibits bactericidal activity against mycobacteria and is the first-line agent for TB.
- Common side effects include gastrointestinal disturbances, CNS effects, and dermatologic reactions.

Pharmacokinetics of Isoniazid

Absorbed rapidly after oral administration, with bioavailability reduced when taken with food.
Metabolized primarily by acetylation, results can vary with genetic differences in patients.
Caution advised for use in patients with liver disease due to potential hepatotoxicity.

Hepatotoxicity of Isoniazid

Symptoms of toxicity include elevated transaminases and bilirubin, alongside signs of nausea and jaundice.
Hepatotoxicity linked to N-acetyl transferase metabolism and reactive intermediate formation.
Risk of increased hepatotoxic effects when combined with acetaminophen or phenytoin.

Side Effects of Rifampin

Gastrointestinal issues like nausea and diarrhea are frequently reported.
Central nervous system effects may include headache and fever.
Potential dermatologic effects include rash and itching.
Hematological side effects can manifest as thrombocytopenia and neutropenia.

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Description

This quiz focuses on the pharmacological treatment methods for tuberculosis. Designed for students of the Management & Science University, it covers key concepts and therapeutic strategies in respiratory system drug therapy. Prepare to test your knowledge on effective treatments and management of this respiratory affliction.

Drug Therapy of Tuberculosis - 3rd Edition