Cephalosporins

Correct Answer: B

Rationale: Cephalosporins are a class of beta-lactam antibiotics, containing a beta-lactam ring in their chemical structure. Option B, "Are less vulnerable to beta-lactamase enzyme," is correct because cephalosporins are less susceptible to degradation by beta-lactamase enzymes compared to penicillins. This is due to the presence of a dihydrothiazine ring in cephalosporins, which provides some protection against beta-lactamase enzymes. Option A, "Are more vulnerable to beta-lactamase enzyme," is incorrect because, as mentioned, cephalosporins are actually less vulnerable to beta-lactamase enzymes compared to penicillins. Option C, "Do not possess beta-lactam ring," is incorrect because cephalosporins do contain a beta-lactam ring in their structure, which is essential for their antibacterial activity. Option D, "Have multiple beta-lactam rings," is incorrect because cephalosporins typically have one beta-lactam ring in their chemical structure, not multiple rings. In an educational context, understanding the susceptibility of antibiotics to beta-lactamase enzymes is crucial for selecting appropriate treatment options for bacterial infections. Knowing that cephalosporins are less vulnerable to beta-lactamase enzymes compared to penicillins can help healthcare professionals make informed decisions when prescribing antibiotics to patients.

Correct Answer: B

Rationale: In this question, the correct answer is B) Fusidic acid. Fusidic acid is a steroidal antibiotic that is commonly used to treat bacterial infections by inhibiting bacterial protein synthesis. It is not only effective against a wide range of bacteria but also has anti-inflammatory properties due to its steroid structure. Option A) Nalidixic acid is a synthetic antibiotic that works by inhibiting bacterial DNA replication, specifically targeting Gram-negative bacteria. It is not a steroidal antibiotic. Option C) Spectinomycin is an aminoglycoside antibiotic that disrupts bacterial protein synthesis. It is not a steroidal antibiotic. Option D) Nitrofurantoin is an antibiotic commonly used to treat urinary tract infections by interfering with bacterial cell wall synthesis. It is not a steroidal antibiotic. Educationally, understanding the classification and mechanism of action of different antibiotics is crucial for healthcare professionals to make informed decisions regarding the appropriate treatment of infections. Knowing which antibiotics are steroidal, bacteriostatic, or bactericidal helps in selecting the most effective drug based on the type of infection and the causative organism. This knowledge is vital in clinical practice to ensure optimal patient outcomes and prevent antibiotic resistance.

Correct Answer: C

Rationale: The correct answer is C) The lipoprotein-peptidoglycan cell wall of gram-negative organisms prevents entry of penicillin. Benzyl penicillin is ineffective in gram-negative infections because gram-negative bacteria have an extra outer membrane composed of lipoproteins and lipopolysaccharides that act as a barrier, preventing the entry of penicillin. This outer membrane is not present in gram-positive bacteria, making them susceptible to benzyl penicillin. Option A is incorrect because penicillinase, an enzyme that degrades penicillin, is produced by both gram-positive and gram-negative organisms, but it is not the main reason benzyl penicillin is ineffective against gram-negative bacteria. Option B is incorrect because benzyl penicillin inhibits the cross-linking of peptidoglycan chains in the bacterial cell wall by binding to penicillin-binding proteins, which are involved in the final steps of cell wall synthesis. This mechanism is not related to D-alanine incorporation. Understanding the differences in cell wall structures between gram-positive and gram-negative bacteria is crucial in selecting the appropriate antibiotic therapy. This knowledge helps healthcare professionals make informed decisions to effectively treat bacterial infections and prevent the development of antibiotic resistance.

Correct Answer: A

Rationale: Rationale: The correct answer is A) Hypotension. Basiliximab is a monoclonal antibody that targets the IL-2 receptor on activated T lymphocytes, thus inhibiting T cell activation. Hypotension can occur as a side effect of basiliximab due to its potential to affect blood pressure regulation by impacting the immune response. Option B) Delayed, severe dyspnoea and wheezing is not a commonly reported side effect of basiliximab. These symptoms are more commonly associated with respiratory conditions or allergic reactions. Option C) Cardiomyopathy is not a known side effect of basiliximab. Cardiomyopathy involves damage to the heart muscle and is not directly related to the mechanism of action of IL-2 receptor blocking antibodies. Option D) Aseptic meningitis is not a typical side effect of basiliximab. Aseptic meningitis is more commonly associated with viral infections or certain medications, not with IL-2 receptor blocking antibodies. Educational Context: Understanding the potential side effects of drugs used in the treatment of immune system disorders is crucial for healthcare professionals. Basiliximab is often used in transplant recipients to prevent organ rejection. By knowing the side effect profile of basiliximab, healthcare providers can monitor patients effectively and intervene promptly if adverse reactions occur. This knowledge contributes to safe and effective patient care in the management of immune-related conditions.

Correct Answer: A

Rationale: In the management of acute anaphylactic shock following a bee sting out of hospital and without monitoring facilities, the correct option is A) Intramuscular adrenaline (epinephrine) (0.5-1 mL, 1 in 1000). Adrenaline is the first-line treatment for anaphylaxis as it acts rapidly to counteract the severe allergic reaction. When administered intramuscularly, it can quickly reach the bloodstream and exert its effects, making it suitable for use in emergency situations like anaphylactic shock. Option B) Intravenous adrenaline (epinephrine) (10 mL, 1 in 10000) is not recommended in this scenario as intravenous administration of adrenaline is more complex and should be reserved for healthcare settings where monitoring and resuscitation equipment are available due to the risk of adverse effects like arrhythmias. Option C) Intravenous hydrocortisone is not the immediate treatment of choice for acute anaphylactic shock. While corticosteroids may be used as an adjunct therapy to prevent biphasic reactions, they do not provide the rapid response needed in an emergency like anaphylaxis. Option D) Intravenous chlorpheniramine is also not the recommended treatment for acute anaphylactic shock. Antihistamines like chlorpheniramine can help with itching and hives in less severe allergic reactions but are not sufficient to reverse the life-threatening symptoms of anaphylaxis. In an educational context, it is essential for healthcare providers and individuals to be familiar with the appropriate management of anaphylaxis, including the use of adrenaline as the first-line treatment. Understanding the rationale behind the choice of treatment options can help ensure timely and effective interventions in emergency situations, potentially saving lives.