Addition of clavulanic acid to amoxicillin is to

Correct Answer: B

Rationale: In the context of this question on the addition of clavulanic acid to amoxicillin, the correct answer is B) Enhance the anti-bacterial activity of amoxicillin. Clavulanic acid is a beta-lactamase inhibitor that is often combined with amoxicillin to protect amoxicillin from being degraded by beta-lactamase enzymes produced by certain bacteria. By inhibiting beta-lactamase, clavulanic acid allows amoxicillin to exert its antibacterial effects effectively, hence enhancing its antibacterial activity. Option A) Decrease the renal excretion of amoxicillin is incorrect because clavulanic acid does not affect the renal excretion of amoxicillin. Option C) Decrease the biotransformation of amoxicillin is incorrect as clavulanic acid's main role is to protect amoxicillin from enzymatic degradation rather than affecting its biotransformation. Option D) To increase oral absorption of amoxicillin is also incorrect because clavulanic acid does not directly impact the oral absorption of amoxicillin. In an educational context, understanding the rationale behind combining clavulanic acid with amoxicillin is crucial for healthcare professionals, particularly in the field of pharmacology and infectious diseases. This knowledge helps in choosing the appropriate antibiotic therapy, especially in cases where beta-lactamase-producing bacteria are involved. It also underscores the importance of combination therapy in combating antibiotic resistance, as these combinations can enhance the effectiveness of antibiotics against resistant strains.

Correct Answer: C

Rationale: In this question, the correct answer is C) Tetracyclines and chloramphenicol. These antibiotics inhibit protein synthesis in cells by targeting the bacterial ribosomes, thereby preventing the translation of mRNA into proteins. Tetracyclines bind to the 30S ribosomal subunit, while chloramphenicol inhibits the peptidyl transferase activity of the 50S ribosomal subunit. Option A) Sulphonamides and PAS are not antibiotics that inhibit protein synthesis. Sulphonamides work by inhibiting folic acid synthesis, while PAS is used in the treatment of tuberculosis. Option B) Isoniazid and PAS are also not antibiotics that inhibit protein synthesis. Isoniazid is used in the treatment of tuberculosis by inhibiting mycolic acid synthesis in the bacterial cell wall. Option D) Penicillin and cephalosporins are beta-lactam antibiotics that inhibit cell wall synthesis by targeting penicillin-binding proteins, not protein synthesis. Understanding the mechanisms of action of different antibiotics is crucial for healthcare professionals to make informed decisions regarding the selection of appropriate antibiotics for treating bacterial infections. Knowing which antibiotics target protein synthesis, cell wall synthesis, or other bacterial processes helps in effectively combating bacterial infections and preventing antibiotic resistance.

Correct Answer: B

Rationale: In the context of drugs for the immune system, understanding the activity of antibiotics like Streptomycin at different pH levels is crucial for their effectiveness. The correct answer, B) pH 8.5 than pH 5.5 of urine, is based on the pharmacokinetics of Streptomycin. Streptomycin is more active at alkaline pH levels like 8.5 because it is a weak base and its solubility and activity increase in alkaline environments. This is important to know for dosing and treatment efficacy. Option A) pH 5.5 than pH 8.5 of urine is incorrect because acidic pH levels would actually decrease the activity of Streptomycin. In acidic conditions, Streptomycin may become less soluble and therefore less effective. Option C) Equally active at all pH of urine is incorrect because, as mentioned earlier, Streptomycin's activity is pH-dependent due to its chemical properties as a weak base. It is not equally active across all pH levels. Option D) All of the above is incorrect because Streptomycin does not exhibit consistent activity across different pH levels. Understanding this concept is important in clinical practice when prescribing antibiotics and ensuring their optimal effectiveness in treating infections.

Correct Answer: A

Rationale: Benzylpenicillin, also known as penicillin G, is not used orally because it is destroyed by the acidic environment of the stomach. This leads to incomplete absorption of the drug when taken orally. The correct answer A is the most accurate because oral administration of benzylpenicillin would render it ineffective due to its susceptibility to acid degradation. Option B is incorrect because even if benzylpenicillin were well absorbed from the intestine, the issue lies with its destruction in the stomach, making absorption from the intestine irrelevant for oral administration. Option C is also incorrect as severe diarrhea is not a known side effect of benzylpenicillin. The primary reason for not using benzylpenicillin orally is its susceptibility to being destroyed by stomach acid. In an educational context, understanding the pharmacokinetics of drugs is crucial for healthcare professionals. Knowing why certain drugs cannot be administered via specific routes helps in ensuring their efficacy and patient safety. This question highlights the importance of drug administration routes and their implications on drug effectiveness.

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.