Pharmacology trans - Principle of Antimicrobial Therapy (2026)

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Questions and Answers

What is the main reason for using a combination of drugs in anti-TB treatment?

To achieve synergy to combat resistance (correct)

To simplify treatment regimens

To increase the likelihood of resistance

To reduce side effects of each drug

What does co-trimoxazole consist of?

Clarithromycin and amoxicillin

Azithromycin and doxycycline

Ciprofloxacin and metronidazole

Sulfamethoxazole and trimethoprim (correct)

Which enzyme does trimethoprim inhibit in the folate synthesis pathway?

Folate synthase

Folate transport protein

Dihydrofolate reductase (correct)

Dihydropteroate synthetase

What is a potential consequence of monotherapy in treating TB?

Increased likelihood of drug resistance Signup and view all the answers

What is an important characteristic of acquired resistance in patients on anti-TB drugs?

It involves forced mutation under treatment Signup and view all the answers

In a mixed infection, what might be required for effective treatment?

Combination of antifungal and antimicrobial agents Signup and view all the answers

What are Koplik spots associated with?

Measles Signup and view all the answers

What does the term 'amplifier effect' refer to in the context of MDR-TB?

Progressive resistance to remaining drugs due to initial resistance development Signup and view all the answers

Which type of transmission is primarily associated with IV drug use?

Common vehicle Signup and view all the answers

What is a recommended preventative measure against malaria?

Mosquito nets Signup and view all the answers

What does the expression '1 in 10 quintillion' signify in the context of drug resistance?

The likelihood of spontaneous resistance to multiple agents Signup and view all the answers

Which of the following is an example of a mixed infection?

Sepsis with a superinfection of Candida albicans Signup and view all the answers

Which of the following is a key factor in determining antimicrobial therapy?

History and physical examination Signup and view all the answers

Which type of infection is NOT associated with exogenous transmission?

Endogenous infections Signup and view all the answers

What is the primary difficulty with combining multiple antibiotics?

They can destroy normal flora Signup and view all the answers

Which drug should be stopped first if a patient presents with jaundice and is taking three unspecified medications?

Erythromycin estolate Signup and view all the answers

What type of therapy is recommended for managing tuberculosis?

Combination therapy Signup and view all the answers

What is a characteristic of the drug chloramphenicol?

Hematologic toxicity Signup and view all the answers

What is the likelihood of developing a resistant strain when treated with isoniazid?

1 in 10^4 Signup and view all the answers

Which of the following drugs is classified as an aminoglycoside?

Streptomycin Signup and view all the answers

What is the most hepatotoxic of the erythromycins?

Erythromycin estolate Signup and view all the answers

How does natural resistance in Mycobacterium tuberculosis occur?

From predictable random mutation Signup and view all the answers

Which drug is not commonly used systemically anymore?

Polymyxin Signup and view all the answers

Which drug is given a high chance of developing a mutant strain during therapy at 1 in 10^3?

Pyrazinamide Signup and view all the answers

In combination therapy for Hansen’s disease, how many drugs are typically used?

Two or more Signup and view all the answers

What characterizes the signs and symptoms discussed?

They may not align with typical descriptions. Signup and view all the answers

What are the whitish plaques in the large intestine associated with?

The suppression of normal flora of the colon. Signup and view all the answers

What does iatrogenesis refer to?

Induction of disease by medical treatment or procedures. Signup and view all the answers

What is a notable feature of the infections mentioned?

They are generally more resistant to cure than community-acquired infections. Signup and view all the answers

What can be a consequence of iatrogenesis in patients?

Prolonged hospital stays and higher costs. Signup and view all the answers

Why are the microorganisms mentioned in the context resistant to treatment?

They have adapted to hospital environments and treatments. Signup and view all the answers

What is a key challenge in predicting patient signs and symptoms?

They can differ from established clinical guidelines. Signup and view all the answers

How do community-acquired infections differ from those discussed in terms of treatment?

Community-acquired infections are generally easier to treat. Signup and view all the answers

What does the presence of whitish plaques suggest?

A secondary effect of disrupted normal flora. Signup and view all the answers

What is an important point regarding the cost of care in cases of iatrogenesis?

It leads to increased costs due to prolonged hospital stays. Signup and view all the answers

What does the term 'antimicrobial' refer to?

Substances produced by microorganisms that kill or inhibit other microorganisms Signup and view all the answers

What major role did Alexander Fleming play in microbiology?

He observed that a mold could inhibit bacterial growth. Signup and view all the answers

Which factor is NOT related to the infecting organism in the treatment of infections?

The socioeconomic status of the infected individual Signup and view all the answers

What is meant by 'antimicrobial prophylaxis'?

Administering antimicrobials to prevent infection before it occurs Signup and view all the answers

Which of the following statements about antibiotics is incorrect?

All antibiotics are effective against viruses. Signup and view all the answers

In what year did Alexander Fleming make his notable discovery regarding antibiotics?

1928 Signup and view all the answers

What is the main concern associated with the use of antimicrobial combinations?

They may lead to greater toxicity and side effects. Signup and view all the answers

Which method is NOT typically associated with the classification of antimicrobials?

According to the geographical region of usage Signup and view all the answers

What is an advantage of using antimicrobial combinations in treatment?

They can provide a broader spectrum of activity against multiple organisms. Signup and view all the answers

Which of the following is NOT a common disadvantage of using antimicrobials?

Improvement in patient outcomes Signup and view all the answers

Study Notes

Reasons for Using Combinations of Antimicrobial Agents

Combination therapy enhances efficacy against tuberculosis (TB) by multiplying resistance probabilities, reducing the chance of resistance development significantly (1 in 10^19).
Co-trimoxazole consists of sulfamethoxazole and trimethoprim; both act as folate antagonists to inhibit the synthesis of essential components in bacteria.
Trimethoprim specifically inhibits dihydrofolate reductase, while sulfamethoxazole inhibits dihydropteroate synthetase.
Resistance to multiple unrelated antimicrobial agents arises from the independent probabilities of each drug's resistance.
Acquired resistance to TB occurs predictably during monotherapy and can amplify with multi-drug resistant TB (MDR-TB), leading to comprehensive resistance among multiple drugs in the regimen.

Treatment for Mixed Infections

Treatment requires using different antimicrobials to target specific pathogens (e.g., treating sepsis alongside a superinfection like Candida albicans).

Treatment of Severe Infections

Understanding factors related to the pathogen, epidemiological elements, and host conditions is crucial in managing severe infections.

Antimicrobial Prophylaxis and Failure

Prophylactic measures aim to prevent infections during high-risk situations.
Broad-spectrum antibiotics might be used empirically based on presentation; however, their use can lead to resistance.

Prevention of Resistance

Combination therapies, such as in tuberculosis (quadruple treatments), are essential in minimizing resistance development.
Natural resistance can arise through random mutation and requires careful management of treatment regimens.

Iatrogenesis

Iatrogenesis refers to a disease induced inadvertently by medical treatment, which can complicate patient health outcomes.
Examples include hematologic toxicity from drugs like Chloramphenicol and neurotoxicity from aminoglycosides.

Transmission and Acquisition of Infections

Infections can be transmitted through various means, including exogenous (external sources) and endogenous (from normal flora).
Acquisition methods include contact (e.g., sexually transmitted infections), inhalation (e.g., tuberculosis), common vehicles (e.g., handled food), and vector-borne routes (e.g., malaria).

Key Points on Antimicrobial Therapy

Delivering effective antimicrobial therapy should not rely solely on non-specific methods of diagnosis, avoiding generalizations.
Patient history and physical examinations are crucial for formulating appropriate treatment strategies and understanding patients' current health statuses.

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Description

This quiz explores the reasons for using combinations of antimicrobial agents, particularly in the treatment of tuberculosis (TB). It highlights concepts such as synergy in drug effectiveness and the mathematical calculations involved in assessing treatment efficacy. Enhance your understanding of this critical topic in infectious disease management.