# Antimicrobial Principles and Beta-Lactams for NEET PG Pharmacology: WHO AWaRe, ICMR Guidelines, Penicillins, Cephalosporins, Carbapenems Source: https://tracknation.in/story/antimicrobial-principles-and-beta-lactams-for-neet-pg-pharmacology-who-aware-icmr-guidelines-penicillins-cephalosporins-carbapenems (TrackNation — free UPSC notes with PYQs) > NEET PG Pharmacology: WHO AWaRe groups and the 60% Access target, India's ICMR antimicrobial guidelines (stewardship, de-escalation, typhoid, cystitis, surgical prophylaxis), penicillins, amoxicillin-clavulanate, benzathine penicillin, ceftriaxone, piperacillin-tazobactam, meropenem, vancomycin, linezolid and colistin, with a diagram, hooks, vignette MCQs and cards. ## Start Here 🎯 **Exam priority: Very high.** *Expect: AWaRe groups, the antibiotic for typhoid in India, surgical prophylaxis timing, amoxicillin rash in glandular fever, ceftriaxone with calcium, vancomycin infusion reactions and linezolid toxicity.* CBME mapping: **PH 8.1–8.3**. Indian guidance: **ICMR Treatment Guidelines for Antimicrobial Use in Common Syndromes (2nd edition, 2019)**; ICMR's 2022 revision was not available to download, so 2019 figures are used. ## WHO AWaRe and Stewardship *WHO AWaRe groups with examples from the 2023 classification. Drawn by TrackNation.* - **Access**: narrow spectrum, good safety. **Watch**: broader spectrum; first choice only in more severe infections or where resistance to Access drugs is likely. **Reserve**: last choice for multidrug-resistant infections. - WHO target: at least **60%** of national antibiotic use should be Access antibiotics. - **Stewardship** (ICMR): coordinated measures to improve choice, dose, duration and route; review empirical therapy and **de-escalate** once cultures return. ## ICMR Choices for Common Syndromes - **Typhoid**: quinolone resistance up to 69% (S. Typhi) and 23% (S. Paratyphi A); resistance is low to co-trimoxazole, chloramphenicol and third-generation cephalosporins. Preferred: oral cefixime or azithromycin, or IV ceftriaxone; alternatives (co-trimoxazole, chloramphenicol, ciprofloxacin) by susceptibility; 10–14 days. - **Acute cystitis**: nitrofurantoin is the drug of choice. - **Surgical prophylaxis**: first dose within 1 hour before incision — e.g. a single IV cefazolin 2 g within 60 minutes before caesarean incision. ## Beta-Lactams and Other Key Drugs | **Drug (AWaRe group)** | **Exam point (label / ICMR)** | | Amoxicillin (Access) | Rash in most patients with infectious mononucleosis; contraindicated after serious reaction to any beta-lactam | | Amoxicillin-clavulanate (Access) | Contraindicated after Augmentin-associated cholestatic jaundice; pointless if the organism makes no beta-lactamase | | Benzathine penicillin (Access) | Deep IM only — never IV; syphilis, yaws; prevents rheumatic fever recurrence | | Cefazolin (Access) | Surgical prophylaxis: single 2 g IV dose within 60 minutes before incision (ICMR) | | Ceftriaxone (Watch) | Not with calcium-containing IV fluids; contraindicated in premature and hyperbilirubinaemic neonates | | Piperacillin-tazobactam (Watch) | Anti-pseudomonal beta-lactam/beta-lactamase inhibitor | | Meropenem (Watch) | Lowers valproate levels → breakthrough seizures | | Vancomycin (Watch) | Infuse over ≥ 60 minutes (flushing, hypotension if fast); kidney injury; ototoxicity | | Linezolid (Reserve) | Weekly blood counts (myelosuppression); serotonin syndrome; tyramine pressor response | | Colistin (Reserve) | Perioral numbness and paraesthesia; apnoea/neuromuscular block, worse in renal failure | ## Traps the Examiner Sets - Typhoid in India: not ciprofloxacin first (high resistance) — ceftriaxone, cefixime or azithromycin. - Prophylactic antibiotic goes in within 60 minutes before the incision, not after. - Benzathine penicillin given IV can be fatal. - Meropenem in an epileptic on valproate → seizures. - Linezolid and colistin are Reserve; vancomycin and carbapenems are Watch. ## Memory Hooks & Shortcuts *Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.* - 🧠 **Traffic light: Green Access, Amber Watch, Red Reserve** — AWaRe colour logic - 🧠 **Sixty goes Green** — ≥ 60% Access target - 🧠 **Typhoid: Cipro Can't (69% resistant)** — use ceftriaxone, cefixime or azithromycin - 🧠 **Cut within the hour** — prophylactic antibiotic ≤ 60 minutes before incision - 🧠 **Bicillin in a Bottom, never a Bag** — deep IM only, never IV - 🧠 **Mero Muffles valproate** — seizures from lower valproate levels - 🧠 **Vanco Very slow (60 min)** — infusion reaction if fast ## Rapid-Revision Cards - Narrow spectrum, safe: amoxicillin, co-amoxiclav, benzathine penicillin, cefazolin, doxycycline, nitrofurantoin. - Ceftriaxone, cefixime, azithromycin, ciprofloxacin, pip-tazo, meropenem, vancomycin. - Colistin, polymyxin B, linezolid, ceftazidime-avibactam, cefiderocol, IV fosfomycin. - ≥ 60% of national use. - Right drug, dose, duration, route; de-escalate. - Quinolones up to 69% (Typhi). - Cefixime/azithromycin oral, ceftriaxone IV; 10–14 d. - Nitrofurantoin. - Cefazolin 2 g IV ≤ 60 min before incision. - Rash. - Serious reaction to any β-lactam → avoid amoxicillin. - Avoid after its cholestatic jaundice. - Deep IM only; syphilis, yaws, RF prophylaxis. - No IV calcium; not in premature/jaundiced neonates. - Valproate ↓ → seizures. - ≥ 60 min infusion; AKI; ototoxicity. - Weekly CBC; serotonin syndrome; tyramine. - Paraesthesia; apnoea in renal failure. ## Sources *Facts in this article were checked against these documents.* - Treatment Guidelines for Antimicrobial Use in Common Syndromes, 2nd edition — Indian Council of Medical Research, 2019 (link) - The WHO AWaRe (Access, Watch, Reserve) antibiotic book — World Health Organization, 2022 (link) - WHO AWaRe classification of antibiotics, 2023 (EML web annex C) — World Health Organization, 2023 (link) - Prescribing labels: amoxicillin, Augmentin, Bicillin L-A, ceftriaxone, Zosyn, meropenem, vancomycin, Coly-Mycin M, Zyvox — DailyMed, US National Library of Medicine, current labels, accessed November 2026 (link) - Competency Based Undergraduate Curriculum, Pharmacology (PH 8.1–8.3) — National Medical Commission, 2024 ## Test Yourself: Practice Questions Twenty-four questions in NEET PG style, most of them clinical vignettes. ## Practice Questions (NEET PG pattern) *Original questions written in the style of the exam: +4 for a correct answer, −1 for a wrong one. Every answer was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.* **Q1.** In the WHO AWaRe classification, amoxicillin belongs to the - (a) Watch group - (b) Access group - (c) Not-recommended group - (d) Reserve group **Answer: (b)** — Access: narrow spectrum, good safety. **Q2.** Ceftriaxone and ciprofloxacin are both in which AWaRe group? - (a) Reserve - (b) Not recommended - (c) Watch - (d) Access **Answer: (c)** — Broader spectrum; first choice only in selected situations. **Q3.** A tertiary hospital uses colistin for carbapenem-resistant Klebsiella. In AWaRe, colistin (IV) is - (a) Access - (b) not classified - (c) Reserve — last resort for multidrug-resistant infections - (d) Watch **Answer: (c)** — Also Reserve: polymyxin B, linezolid, ceftazidime-avibactam, cefiderocol. **Q4.** WHO's national target for antibiotic consumption is that at least - (a) 60% should be Watch antibiotics - (b) 10% should be Reserve - (c) 60% should be Access antibiotics - (d) 90% should be Reserve **Answer: (c)** — WHO AWaRe book. **Q5.** A 22-year-old in Delhi has blood-culture-proven typhoid. Given ICMR's resistance data, a preferred drug is - (a) ciprofloxacin empirically - (b) penicillin G - (c) ceftriaxone (or oral cefixime/azithromycin) - (d) nitrofurantoin **Answer: (c)** — Quinolone resistance up to 69% for S. Typhi; ICMR prefers cefixime or azithromycin orally, ceftriaxone IV; 10–14 days. **Q6.** ICMR's recommended duration of antibiotic treatment for typhoid is - (a) 6 weeks - (b) single dose - (c) 3 days - (d) 10–14 days **Answer: (d)** — ICMR 2019 Table 2.1. **Q7.** A non-pregnant woman has uncomplicated acute cystitis. ICMR's drug of choice is - (a) ceftriaxone - (b) nitrofurantoin - (c) meropenem - (d) colistin **Answer: (b)** — Nitrofurantoin is also an Access antibiotic. **Q8.** For an elective caesarean section, ICMR's antibiotic prophylaxis is - (a) ceftriaxone for 7 days after surgery - (b) a single IV dose of cefazolin 2 g within 60 minutes before incision - (c) meropenem at skin closure - (d) no antibiotic **Answer: (b)** — First dose within one hour before incision. **Q9.** Reviewing a patient on empirical meropenem whose culture grows a sensitive organism, the stewardship action is to - (a) continue meropenem for 6 weeks - (b) add colistin - (c) stop all antibiotics today regardless - (d) de-escalate to a narrower drug **Answer: (d)** — ICMR: evaluate whether empirical therapy can be justified or de-escalated. **Q10.** A teenager with infectious mononucleosis is given amoxicillin and develops a widespread red rash. The explanation is - (a) scarlet fever - (b) true penicillin allergy for life - (c) Stevens-Johnson syndrome - (d) most patients with mononucleosis given amoxicillin develop a rash **Answer: (d)** — Amoxicillin label. **Q11.** A patient had anaphylaxis to a cephalosporin. Amoxicillin is - (a) preferred - (b) safe if given IV - (c) safe - (d) contraindicated (serious reaction to another beta-lactam) **Answer: (d)** — Label contraindication. **Q12.** A man developed cholestatic jaundice during a previous course of amoxicillin-clavulanate. Now - (a) give it IV - (b) only reduce the dose - (c) Augmentin is contraindicated - (d) it is safe to repeat **Answer: (c)** — Contraindication. **Q13.** Benzathine penicillin for secondary prophylaxis of rheumatic fever must be given - (a) IV push - (b) orally - (c) by deep IM injection only — never IV - (d) subcutaneously **Answer: (c)** — Bicillin L-A boxed statement; also for syphilis and yaws. **Q14.** A neonatal unit plans ceftriaxone with calcium-containing IV fluids in a jaundiced premature baby. The label says - (a) safe - (b) contraindicated: risk of ceftriaxone-calcium precipitation; avoid in premature/hyperbilirubinaemic neonates - (c) only reduce the dose - (d) give with extra calcium **Answer: (b)** — Ceftriaxone label. **Q15.** An epileptic on valproate gets meropenem for sepsis and starts having seizures. The cause is - (a) valproate toxicity - (b) meropenem raising valproate levels - (c) meropenem lowering valproate levels - (d) hyponatraemia only **Answer: (c)** — Breakthrough seizures from reduced valproic acid concentrations. **Q16.** During a rapid vancomycin infusion a patient becomes flushed, itchy and hypotensive. The fix is - (a) add calcium - (b) give it as a bolus - (c) infuse over at least 60 minutes - (d) switch to oral route for sepsis **Answer: (c)** — Infusion reaction; also watch kidney injury and ototoxicity. **Q17.** A patient on vancomycin and an aminoglycoside develops rising creatinine. The label warns that vancomycin - (a) only causes rash - (b) causes hypoglycaemia - (c) protects the kidneys - (d) can cause acute kidney injury, more with other nephrotoxins **Answer: (d)** — Risk rises with exposure. **Q18.** A man on linezolid for 3 weeks develops thrombocytopenia. The label advises - (a) doubling the dose - (b) adding an SSRI - (c) no monitoring - (d) weekly complete blood counts (myelosuppression) **Answer: (d)** — Also serotonin syndrome and a tyramine pressor response. **Q19.** A patient on linezolid eats aged cheese and develops a severe headache with high BP. The mechanism is - (a) renal failure - (b) allergy - (c) hypoglycaemia - (d) linezolid's MAO-inhibiting pressor response with tyramine **Answer: (d)** — Label: significant pressor response with linezolid plus tyramine. **Q20.** A patient with renal failure on colistin develops perioral numbness and then breathing difficulty. The concern is - (a) hepatitis - (b) neuromuscular blockade and apnoea, more likely in renal impairment - (c) hypercalcaemia - (d) anaphylaxis to penicillin **Answer: (b)** — Coly-Mycin M label. **Q21.** Augmentin should not be used when culture shows - (a) the organism is amoxicillin-sensitive (no beta-lactamase) - (b) mixed infection - (c) beta-lactamase production - (d) H. influenzae resistance **Answer: (a)** — Clavulanate adds nothing without beta-lactamase. **Q22.** Benzathine penicillin is labelled for the treatment of - (a) typhoid - (b) malaria - (c) tuberculosis - (d) syphilis and yaws **Answer: (d)** — Also prevents recurrence of rheumatic fever and chorea. **Q23.** Which antibiotic is an AWaRe Access drug and the ICMR choice for surgical prophylaxis? - (a) Cefazolin - (b) Meropenem - (c) Linezolid - (d) Colistin **Answer: (a)** — First-generation cephalosporin. **Q24.** ICMR defines antimicrobial stewardship as - (a) banning all antibiotics - (b) coordinated interventions to measure and improve appropriate antibiotic use - (c) giving antibiotics for all fevers - (d) using only Reserve antibiotics **Answer: (b)** — Optimal choice, dose, duration and route. ### Active Recall From memory: define the three WHO AWaRe groups with examples and the Access target; explain stewardship and de-escalation; give ICMR's choices for typhoid, acute cystitis and surgical prophylaxis; and give the key warning for amoxicillin, co-amoxiclav, benzathine penicillin, ceftriaxone, meropenem, vancomycin, linezolid and colistin.