NSGl 533/l NSG533l Examl 1l –l (NEWl
2026/l 2027l Update)l Advancedl
Pharmacologyl Guide|l Questionsl &l
Answersl |l Gradel A|l 100%l Correctl
(Verifiedl Solutions)-l Wilkes
QUESTION
Hypothalamic-Pituitary-Thyroidl (HPT)l Axis
Answer:
l Componentsl ofl thel HPTl Axis
l Hypothalamus
Secretesl TRHl (thyrotropin-releasingl hormone)
l Pituitaryl (anterior)
Secretesl TSHl (thyroid-stimulatingl hormone)
l Thyroidl Gland
Producesl T4l (thyroxine)l andl T3l (triiodothyronine)
T4l =l primaryl circulatingl hormone
T3l =l biologicallyl activel form
l Negativel Feedbackl Loop
Circulatingl T4/T3l suppressl TRHl andl TSH
Lowl thyroidl hormonel →l ↑l TSH
Highl thyroidl hormonel →l ↓l TSH
QUESTION
Whatl isl thel primaryl hormonel ofl thel hypothalamusl inl thel thyroidl axis?
Answer:
TRH.
,QUESTION
Whatl isl thel primaryl hormonel ofl thel pituitaryl inl thel thyroidl axis?
Answer:
TSH.
QUESTION
Whatl arel thel primaryl hormonesl ofl thel thyroidl gland?
Answer:
T4l andl T3.
QUESTION
Whatl isl thel bestl initiall testl forl thyroidl disease?
Answer:
TSH.
QUESTION
Whatl doesl highl TSHl withl lowl T4l indicate?
Answer:
Primaryl hypothyroidism.
QUESTION
Whatl doesl lowl TSHl withl highl T4l indicate?
Answer:
Hyperthyroidism.
QUESTION
Whatl isl thel treatmentl ofl choicel forl hypothyroidism?
Answer:
Levothyroxine.
,Providesl stablel T4l thatl isl peripherallyl convertedl tol T3
Longl half-lifel →l once-dailyl dosing
Predictablel effect
Narrowl therapeuticl indexl →l precisel titrationl usingl TSH
l First-linel forl essentiallyl alll patientsl withl primaryl hypothyroidism.
Avoidl over-replacementl (atriall fibrillation,l osteoporosis)
QUESTION
pregnancyl andl hypothyroidism
Answer:
l Stilll levothyroxinel (ONLYl safel choice)
Keyl pregnancyl changes:
↑l thyroidl hormonel requirementsl (oftenl ↑l dosel byl 25-30%)
Lowerl trimester-specificl TSHl targets
Monitorl TSHl everyl 4l weeksl inl earlyl pregnancy
l Examl pearl:
Untreatedl hypothyroidisml inl pregnancyl ↑l riskl ofl miscarriage,l preeclampsia,l andl
impairedl fetall neurodevelopment.
QUESTION
Whatl isl thel mechanisml ofl levothyroxine?
Answer:
Syntheticl T4l replacement.
QUESTION
Whatl doesl narrowl therapeuticl indexl mean?
Answer:
Smalll marginl betweenl therapeuticl andl toxicl dose.
Dosel changesl arel smalll (usuallyl 12.5-25l mcgl increments)
l Keyl rule:
Adjustl dosel →l waitl 6-8l weeksl →l recheckl TSH
, QUESTION
Whatl isl al dosingl considerationl forl levothyroxinel inl thel elderly?
Answer:
Avoidl suppressingl TSHl →l ↑l arrhythmial &l fracturel risk
Thyroidl hormonel ↑l heartl rate,l myocardiall oxygenl demand,l andl contractility
Elderlyl patientsl have:
Reducedl physiologicl reserve
Higherl prevalencel ofl occultl coronaryl arteryl disease
Riskl ifl startedl tool aggressively
Atriall fibrillation
Angina
Myocardiall infarction
l Implementation
Startl lowl dosel levothyroxinel (e.g.,l 12.5-25l mcg/day)
Titratel slowlyl everyl 6-8l weeksl basedl onl TSH
QUESTION
durationl ofl hypothyroidisml considerations
Answer:
Thel longerl hypothyroidisml hasl beenl present,l thel morel thel bodyl hasl adaptedl tol al low-
thyroidl state.
Whyl itl matters
Chronicl hypothyroidisml leadsl to:
Reducedl cardiacl output
Decreasedl metabolism
Rapidl normalizationl canl overwhelml adaptivel mechanisms
Risk
Cardiovascularl stress
Decompensation
l Implementation
Treatl chronicl orl long-standingl hypothyroidisml gradually
Avoidl fulll replacementl initiallyl unlessl youngl andl healthy
QUESTION
Whatl isl al dosingl considerationl forl levothyroxinel inl cardiacl disease?
2026/l 2027l Update)l Advancedl
Pharmacologyl Guide|l Questionsl &l
Answersl |l Gradel A|l 100%l Correctl
(Verifiedl Solutions)-l Wilkes
QUESTION
Hypothalamic-Pituitary-Thyroidl (HPT)l Axis
Answer:
l Componentsl ofl thel HPTl Axis
l Hypothalamus
Secretesl TRHl (thyrotropin-releasingl hormone)
l Pituitaryl (anterior)
Secretesl TSHl (thyroid-stimulatingl hormone)
l Thyroidl Gland
Producesl T4l (thyroxine)l andl T3l (triiodothyronine)
T4l =l primaryl circulatingl hormone
T3l =l biologicallyl activel form
l Negativel Feedbackl Loop
Circulatingl T4/T3l suppressl TRHl andl TSH
Lowl thyroidl hormonel →l ↑l TSH
Highl thyroidl hormonel →l ↓l TSH
QUESTION
Whatl isl thel primaryl hormonel ofl thel hypothalamusl inl thel thyroidl axis?
Answer:
TRH.
,QUESTION
Whatl isl thel primaryl hormonel ofl thel pituitaryl inl thel thyroidl axis?
Answer:
TSH.
QUESTION
Whatl arel thel primaryl hormonesl ofl thel thyroidl gland?
Answer:
T4l andl T3.
QUESTION
Whatl isl thel bestl initiall testl forl thyroidl disease?
Answer:
TSH.
QUESTION
Whatl doesl highl TSHl withl lowl T4l indicate?
Answer:
Primaryl hypothyroidism.
QUESTION
Whatl doesl lowl TSHl withl highl T4l indicate?
Answer:
Hyperthyroidism.
QUESTION
Whatl isl thel treatmentl ofl choicel forl hypothyroidism?
Answer:
Levothyroxine.
,Providesl stablel T4l thatl isl peripherallyl convertedl tol T3
Longl half-lifel →l once-dailyl dosing
Predictablel effect
Narrowl therapeuticl indexl →l precisel titrationl usingl TSH
l First-linel forl essentiallyl alll patientsl withl primaryl hypothyroidism.
Avoidl over-replacementl (atriall fibrillation,l osteoporosis)
QUESTION
pregnancyl andl hypothyroidism
Answer:
l Stilll levothyroxinel (ONLYl safel choice)
Keyl pregnancyl changes:
↑l thyroidl hormonel requirementsl (oftenl ↑l dosel byl 25-30%)
Lowerl trimester-specificl TSHl targets
Monitorl TSHl everyl 4l weeksl inl earlyl pregnancy
l Examl pearl:
Untreatedl hypothyroidisml inl pregnancyl ↑l riskl ofl miscarriage,l preeclampsia,l andl
impairedl fetall neurodevelopment.
QUESTION
Whatl isl thel mechanisml ofl levothyroxine?
Answer:
Syntheticl T4l replacement.
QUESTION
Whatl doesl narrowl therapeuticl indexl mean?
Answer:
Smalll marginl betweenl therapeuticl andl toxicl dose.
Dosel changesl arel smalll (usuallyl 12.5-25l mcgl increments)
l Keyl rule:
Adjustl dosel →l waitl 6-8l weeksl →l recheckl TSH
, QUESTION
Whatl isl al dosingl considerationl forl levothyroxinel inl thel elderly?
Answer:
Avoidl suppressingl TSHl →l ↑l arrhythmial &l fracturel risk
Thyroidl hormonel ↑l heartl rate,l myocardiall oxygenl demand,l andl contractility
Elderlyl patientsl have:
Reducedl physiologicl reserve
Higherl prevalencel ofl occultl coronaryl arteryl disease
Riskl ifl startedl tool aggressively
Atriall fibrillation
Angina
Myocardiall infarction
l Implementation
Startl lowl dosel levothyroxinel (e.g.,l 12.5-25l mcg/day)
Titratel slowlyl everyl 6-8l weeksl basedl onl TSH
QUESTION
durationl ofl hypothyroidisml considerations
Answer:
Thel longerl hypothyroidisml hasl beenl present,l thel morel thel bodyl hasl adaptedl tol al low-
thyroidl state.
Whyl itl matters
Chronicl hypothyroidisml leadsl to:
Reducedl cardiacl output
Decreasedl metabolism
Rapidl normalizationl canl overwhelml adaptivel mechanisms
Risk
Cardiovascularl stress
Decompensation
l Implementation
Treatl chronicl orl long-standingl hypothyroidisml gradually
Avoidl fulll replacementl initiallyl unlessl youngl andl healthy
QUESTION
Whatl isl al dosingl considerationl forl levothyroxinel inl cardiacl disease?
