Pharmacology Cheat Sheet
Special Populations and Medicine Systems
Special pharmacology for NEET-PG: paediatric dose rules, teratogens, renal dosing, isotretinoin, glaucoma therapy, and India NLEM 2022 facts.
MedNext Academy | 3 min read
Special Populations and Medicine Systems
Special pharmacology for NEET-PG: paediatric dose rules, teratogens, renal dosing, isotretinoin, glaucoma therapy, and India NLEM 2022 facts.
Special pharmacology covering paediatric and geriatric dosing, teratogens, renal dosing, dermatological and ophthalmic drugs, and regulatory frameworks.
High-yield lines
- Young's rule gives child dose as age divided by age plus 12, times the adult dose, while Clark's rule uses weight in pounds over 150.
- The Cockcroft-Gault formula estimates creatinine clearance and is multiplied by 0.85 for females, guiding dosing of aminoglycosides, digoxin, and metformin.
- Tetracyclines are contraindicated under 8 years for tooth discolouration, and chloramphenicol causes grey baby syndrome in neonates.
- Major human teratogens include thalidomide causing phocomelia, warfarin causing fetal warfarin syndrome, and ACE inhibitors causing renal dysgenesis.
- Metformin is avoided when GFR falls below 30 mL/min because of lactic acidosis risk.
- Isotretinoin is the only acne agent acting on all four pathogenic factors and is a potent teratogen requiring two negative pregnancy tests before starting.
- Terbinafine is the drug of choice for dermatophyte onychomycosis and is hepatotoxic, while griseofulvin is the choice for tinea capitis in children.
- For primary open-angle glaucoma, treatment starts with a prostaglandin analogue, adding a beta-blocker or carbonic anhydrase inhibitor as needed.
- Acute angle-closure crisis is treated with IV acetazolamide, IV mannitol, and topical pilocarpine.
- Mydriatics must never be used in narrow-angle glaucoma because pupil dilation blocks aqueous outflow and precipitates a crisis.
- Slow NAT2 acetylators are prone to isoniazid neuropathy and drug-induced lupus with hydralazine and procainamide.
- The 2022 Indian NLEM lists 384 medicines across 27 therapeutic categories.
- Folic acid 400 micrograms daily is advised for all women planning pregnancy, rising to 4 to 5 mg in high-risk women.
- Rational fixed-dose combinations include anti-tubercular HRZE, levodopa with carbidopa, and amoxicillin with clavulanate.
Mapped competency codes
- PH1.56
- PH1.57
- PH1.58
- PH1.59
- PH1.60
- PH1.61
- PH1.62
- PH1.63
- PH1.64
Continue into the full chapter
This summary maps to PH15-special-pharmacology.
Frequently Asked Questions
Which drugs are contraindicated in young children?
Tetracyclines under 8 years (tooth discolouration), chloramphenicol in neonates (grey baby syndrome), and fluoroquinolones under 18 years (cartilage concern).
What are key human teratogens?
Thalidomide (phocomelia), warfarin (fetal warfarin syndrome), and ACE inhibitors or ARBs (renal dysgenesis and oligohydramnios).
What is the drug of choice for onychomycosis and for tinea capitis?
Terbinafine for dermatophyte onychomycosis; griseofulvin for tinea capitis in children.
Why are mydriatics contraindicated in narrow-angle glaucoma?
Pupillary dilation crowds the drainage angle and blocks aqueous outflow, precipitating acute angle-closure.
Continue reading
Cheat SheetsAll Pharmacology cheat sheets
Browse the complete authored set for this subject.
Open the complete revision pathway
Explore clinician-written learning resources, structured revision and practice across the MedNext platform.
Open in the MedNext appSee plans

