Safe Prescribing — MCQs

A 56-year-old man with type 2 diabetes is established on insulin detemir 32 units subcutaneously at 22:00 hours and insulin aspart 8 units three times daily with meals. Over the past week, his pre-breakfast glucose readings have been consistently between 3.8-4.2 mmol/L, while his pre-lunch, pre-dinner, and bedtime readings are all 7-9 mmol/L. He denies any hypoglycaemic symptoms. What is the most appropriate adjustment to his insulin regimen?

Q163

A 71-year-old man with atrial fibrillation is on warfarin with a target INR of 2.0-3.0. He is admitted with community-acquired pneumonia and started on clarithromycin 500mg twice daily. His INR on admission is 2.4. After 3 days of antibiotics, he develops haematuria and his INR is found to be 7.8. He is haemodynamically stable with no other bleeding. What is the most appropriate immediate management?

Q164

A 39-year-old woman with type 1 diabetes on basal-bolus insulin therapy (insulin glargine 24 units at bedtime and insulin aspart with meals) is admitted with acute appendicitis requiring emergency surgery. She last ate 6 hours ago. Her current blood glucose is 8.2 mmol/L. The operation is scheduled in 2 hours. What is the most appropriate management of her insulin during the perioperative period?

Q165

According to the National Patient Safety Agency guidance on high-risk medicines, which of the following monitoring parameters is specifically recommended for patients on long-term amiodarone therapy?

Q166

A 50-year-old man with bipolar disorder has been stable on lithium carbonate 800mg twice daily for 18 months. His most recent lithium level 3 months ago was 0.75 mmol/L (therapeutic range 0.6-1.0 mmol/L). He now presents to his GP with a 5-day history of diarrhoea and vomiting following a gastrointestinal infection. He appears clinically dehydrated with a coarse tremor. What is the most appropriate immediate management?

Q167

A 63-year-old woman with metastatic breast cancer is started on enoxaparin for prophylaxis of venous thromboembolism. She has a past medical history of hypertension and stage 3 chronic kidney disease with eGFR of 35 ml/min/1.73m². Her weight is 55 kg. According to current prescribing guidance, what adjustment should be made to the standard dose of enoxaparin?

Q168

A 63-year-old man with type 2 diabetes is established on a complex insulin regimen comprising insulin glargine 38 units at 22:00, insulin aspart 12 units with breakfast, 10 units with lunch, and 14 units with evening meal. He is admitted with acute pancreatitis and made nil by mouth, and a variable rate intravenous insulin infusion (VRIII) is commenced at 09:00 on Monday. His last dose of insulin glargine was at 22:00 on Sunday night. He improves and is ready to resume eating at 18:00 on Wednesday. When is the most appropriate time to discontinue the VRIII?

Q169

A 77-year-old man with atrial fibrillation and a mechanical mitral valve replacement is on warfarin with target INR 3.0-4.0. He requires urgent colonoscopy for suspected lower gastrointestinal bleeding (haemoglobin dropped from 125 to 95 g/L over 48 hours with melaena). His current INR is 3.6. He is haemodynamically stable. What is the most appropriate anticoagulation management strategy prior to the procedure?

Q170

A 42-year-old woman with newly diagnosed type 1 diabetes is being established on a basal-bolus insulin regimen. Over the past week, her pre-meal and bedtime capillary glucose readings have been: breakfast 6.2-7.8 mmol/L, lunch 11.5-14.2 mmol/L, evening meal 7.1-8.9 mmol/L, bedtime 9.8-12.4 mmol/L. She is currently on insulin detemir 18 units at bedtime and insulin lispro 6 units before each meal. Which insulin adjustment would most appropriately address her glucose pattern?

Safe Prescribing UK Medical PG Practice Questions and MCQs

Question 161: What is the recommended initial frequency for monitoring international normalised ratio (INR) when a patient is first started on warfarin therapy following a deep vein thrombosis?

A. Daily until INR is stable in therapeutic range for 2 consecutive days (Correct Answer)
B. Every 2-3 days until INR is stable in therapeutic range
C. Weekly for the first month then monthly
D. Daily for the first week then twice weekly
E. Every 2 days for the first week then weekly

Explanation: ***Daily until INR is stable in therapeutic range for 2 consecutive days*** - **Daily monitoring** is essential during the initiation phase because of **warfarin's delayed onset** and the high degree of inter-individual variability in response. - Stabilizing the **INR** within the therapeutic range (typically 2.0-3.0 for **DVT**) for two consecutive days ensures the patient is safely anticoagulated before extending monitoring intervals. *Every 2-3 days until INR is stable in therapeutic range* - Waiting 2-3 days initially is risky because **warfarin** inhibits **Protein C and S** first, potentially creating a **prothrombotic state** that requires close observation. - This frequency is more appropriate for the **maintenance phase** after initial stabilization has already been achieved. *Weekly for the first month then monthly* - **Weekly monitoring** at the start of therapy is inadequate and poses a high risk of **bleeding complications** or subtherapeutic dosing. - **Monthly monitoring** is only reserved for patients who have demonstrated long-term **INR stability** on a consistent dose. *Daily for the first week then twice weekly* - While it starts with daily checks, transitioning to twice weekly based on a fixed timeline rather than **therapeutic stability** increases the risk of dosage errors. - The decision to reduce frequency must be based on reaching the **target INR range** for two consecutive days, not just the passage of one week. *Every 2 days for the first week then weekly* - Monitoring every 2 days during the first week is insufficient to detect rapid fluctuations in **clotting factor levels** as different factors have different **half-lives**. - A **weekly** transition is premature for a patient who hasn't yet reached a proven **steady state** on their prescribed warfarin dose.

Question 162: A 56-year-old man with type 2 diabetes is established on insulin detemir 32 units subcutaneously at 22:00 hours and insulin aspart 8 units three times daily with meals. Over the past week, his pre-breakfast glucose readings have been consistently between 3.8-4.2 mmol/L, while his pre-lunch, pre-dinner, and bedtime readings are all 7-9 mmol/L. He denies any hypoglycaemic symptoms. What is the most appropriate adjustment to his insulin regimen?

A. Reduce insulin detemir by 4 units (to 28 units) (Correct Answer)
B. Reduce breakfast insulin aspart by 2 units (to 6 units)
C. Increase all insulin aspart doses by 2 units
D. Split insulin detemir to twice daily dosing
E. Reduce dinner insulin aspart by 2 units (to 6 units)

Explanation: ***Reduce insulin detemir by 4 units (to 28 units)***- The pre-breakfast glucose readings (3.8-4.2 mmol/L) are at the **lower limit of target**, indicating the **basal insulin** (detemir) given at 22:00 is too high and risks **nocturnal hypoglycaemia**.- A dose reduction of approximately **10-15%** (4 units is 12.5% of 32 units) is the standard safe adjustment to correct fasting levels.*Reduce breakfast insulin aspart by 2 units (to 6 units)*- Reducing **breakfast bolus** insulin would primarily affect the **pre-lunch** glucose levels, not the pre-breakfast levels.- Since his pre-lunch readings (7-9 mmol/L) are already at the upper end of the target, this change would likely lead to **hyperglycaemia**.*Increase all insulin aspart doses by 2 units*- Increasing the **bolus insulin** doses would lower daytime glucose but does not address the primary concern of near-hypoglycaemic **fasting glucose**.- This action increases the overall risk of **daytime hypoglycaemia** while leaving the excessive basal dose unchanged.*Split insulin detemir to twice daily dosing*- **Splitting the dose** is usually indicated if there is significant "wear-off" where the basal insulin does not last 24 hours, which is not evidenced here.- The current issue is the **total dose** of basal insulin being too high overnight, not its duration of action.*Reduce dinner insulin aspart by 2 units (to 6 units)*- **Dinner bolus** insulin affects the **bedtime glucose** reading rather than the fasting glucose reading the next morning.- This adjustment would increase his bedtime glucose (currently 7-9 mmol/L) without correcting the low morning readings caused by the **insulin detemir**.

Question 163: A 71-year-old man with atrial fibrillation is on warfarin with a target INR of 2.0-3.0. He is admitted with community-acquired pneumonia and started on clarithromycin 500mg twice daily. His INR on admission is 2.4. After 3 days of antibiotics, he develops haematuria and his INR is found to be 7.8. He is haemodynamically stable with no other bleeding. What is the most appropriate immediate management?

A. Give 5mg oral vitamin K, withhold warfarin, and recheck INR in 24 hours
B. Give 10mg intravenous vitamin K and 4-factor prothrombin complex concentrate
C. Withhold warfarin for 2 doses and recheck INR daily without vitamin K
D. Give 1-2mg intravenous vitamin K, withhold warfarin, and recheck INR in 24 hours (Correct Answer)
E. Stop warfarin permanently and switch to direct oral anticoagulant

Explanation: ***Give 1-2mg intravenous vitamin K, withhold warfarin, and recheck INR in 24 hours*** - An **INR of 7.8** with **minor bleeding** (haematuria) in a haemodynamically stable patient warrants rapid, but not aggressive, reversal of anticoagulation. - **Low-dose intravenous vitamin K** (1-2mg) is the recommended intervention, as it provides a predictable and timely reduction in INR, along with **withholding warfarin**. *Give 5mg oral vitamin K, withhold warfarin, and recheck INR in 24 hours* - While **oral vitamin K** is an option for elevated INR without bleeding, **intravenous administration** is preferred for active bleeding (like haematuria) due to its faster onset and more reliable effect. - A **5mg dose** of vitamin K may be excessive for minor bleeding, potentially causing **warfarin resistance** for several days, complicating subsequent anticoagulation management. *Give 10mg intravenous vitamin K and 4-factor prothrombin complex concentrate* - **Prothrombin complex concentrate (PCC)** and a high dose of **intravenous vitamin K (10mg)** are reserved for **major life-threatening bleeding** (e.g., intracranial hemorrhage) or urgent surgical needs. - This patient is **haemodynamically stable** with only minor bleeding, making such aggressive and costly reversal measures inappropriate and potentially harmful. *Withhold warfarin for 2 doses and recheck INR daily without vitamin K* - Simply **withholding warfarin** is insufficient to rapidly lower an **INR of 7.8** with active bleeding, as warfarin's anticoagulant effect takes several days to diminish. - Active reversal with **vitamin K** is crucial in this scenario to quickly reduce the INR and mitigate the risk of the minor bleeding progressing to a more serious event. *Stop warfarin permanently and switch to direct oral anticoagulant* - The elevated INR and haematuria are likely due to a **drug-drug interaction** between **warfarin** and **clarithromycin**, a known **CYP3A4 inhibitor**, increasing warfarin's effect. - Permanent cessation of warfarin is not indicated, as the issue is transient; once the INR is controlled and the antibiotic course is complete, warfarin can typically be safely resumed at an adjusted dose.

Question 164: A 39-year-old woman with type 1 diabetes on basal-bolus insulin therapy (insulin glargine 24 units at bedtime and insulin aspart with meals) is admitted with acute appendicitis requiring emergency surgery. She last ate 6 hours ago. Her current blood glucose is 8.2 mmol/L. The operation is scheduled in 2 hours. What is the most appropriate management of her insulin during the perioperative period?

A. Continue basal insulin, omit bolus insulin, and start variable rate intravenous insulin infusion with dextrose (Correct Answer)
B. Stop all subcutaneous insulin and start variable rate intravenous insulin infusion with dextrose
C. Continue both basal and bolus insulin at current doses with hourly glucose monitoring
D. Give 50% of basal insulin dose, omit bolus insulin, and monitor glucose 2-hourly
E. Stop basal insulin, give half dose of bolus insulin, and start intravenous insulin only if glucose >15 mmol/L

Explanation: ***Continue basal insulin, omit bolus insulin, and start variable rate intravenous insulin infusion with dextrose*** - For **Type 1 Diabetes** patients undergoing surgery, **basal insulin** must be continued to prevent the development of **diabetic ketoacidosis (DKA)**. - A **variable rate intravenous insulin infusion (VRIII)**, paired with a glucose substrate like **dextrose**, ensures tight glycemic control during fasting periods and surgical stress. *Stop all subcutaneous insulin and start variable rate intravenous insulin infusion with dextrose* - Discontinuing **long-acting basal insulin** in Type 1 Diabetes increases the risk of **DKA** if the IV infusion is interrupted or stopped prematurely. - Clinical guidelines recommend maintaining the **subcutaneous basal dose** as a safety net, even when using a VRIII. *Continue both basal and bolus insulin at current doses with hourly glucose monitoring* - Administering **bolus insulin** (insulin aspart) when the patient is **NPO** (nil per os) carries a very high risk of inducing severe **hypoglycemia**. - While frequent glucose monitoring is crucial, it does not mitigate the danger of giving short-acting insulin without an appropriate carbohydrate intake. *Give 50% of basal insulin dose, omit bolus insulin, and monitor glucose 2-hourly* - Reducing the **basal insulin** dose to 50% may be insufficient to counteract the **stress-induced hyperglycemia** during acute appendicitis and surgery in a Type 1 diabetic. - For emergency or major surgery, a **VRIII** provides more dynamic and precise glucose management compared to a fixed, reduced subcutaneous dose with less frequent monitoring. *Stop basal insulin, give half dose of bolus insulin, and start intravenous insulin only if glucose >15 mmol/L* - Completely stopping **basal insulin** in Type 1 Diabetes is highly dangerous and will rapidly precipitate **DKA** due to the lack of endogenous insulin production. - Waiting for blood glucose to exceed **15 mmol/L** before initiating intravenous insulin is unsafe, as perioperative targets should ideally be maintained between **6.0-10.0 mmol/L** to prevent complications.

Question 165: According to the National Patient Safety Agency guidance on high-risk medicines, which of the following monitoring parameters is specifically recommended for patients on long-term amiodarone therapy?

A. Monthly electrocardiogram and liver function tests
B. Six-monthly thyroid function tests and annual chest X-ray (Correct Answer)
C. Weekly international normalised ratio and renal function
D. Three-monthly full blood count and serum amiodarone levels
E. Annual echocardiogram and monthly ophthalmic examination

Explanation: ***Six-monthly thyroid function tests and annual chest X-ray*** - **Amiodarone** is a high-iodine compound that can cause **hypothyroidism** or **thyrotoxicosis**, requiring **thyroid function tests (TFTs)** every 6 months. - **Pulmonary toxicity** is a life-threatening complication, necessitating an **annual chest X-ray** to monitor for interstitial lung disease or fibrosis. *Monthly electrocardiogram and liver function tests* - While **Liver Function Tests (LFTs)** are required every 6 months, monthly testing is not the standard recommendation for stable patients. - **Electrocardiograms (ECGs)** are performed at baseline and periodically, but **monthly routine monitoring** is not mandate by NPSA guidelines. *Weekly international normalised ratio and renal function* - **International Normalised Ratio (INR)** monitoring is critical only if amiodarone is used concurrently with **warfarin**, due to a significant drug interaction. - Amiodarone does not typically require **renal function** monitoring, as it is primarily metabolized through the **liver** and excreted in bile. *Three-monthly full blood count and serum amiodarone levels* - **Full blood counts** are not standard monitoring requirements for amiodarone, as it does not commonly cause myelosuppression. - Routine monitoring of **serum amiodarone levels** is not clinically useful or recommended due to the drug's extremely long half-life and large volume of distribution. *Annual echocardiogram and monthly ophthalmic examination* - **Echocardiograms** are not part of routine amiodarone monitoring unless there is a clinical suspicion of worsening heart failure or specific arrhythmias. - **Ophthalmic examinations** are recommended at baseline and only if visual symptoms occur; **monthly examinations** are not required for asymptomatic patients.

Question 166: A 50-year-old man with bipolar disorder has been stable on lithium carbonate 800mg twice daily for 18 months. His most recent lithium level 3 months ago was 0.75 mmol/L (therapeutic range 0.6-1.0 mmol/L). He now presents to his GP with a 5-day history of diarrhoea and vomiting following a gastrointestinal infection. He appears clinically dehydrated with a coarse tremor. What is the most appropriate immediate management?

A. Continue lithium and arrange lithium level within 7 days
B. Reduce lithium dose by 50% and recheck level in 1 week
C. Stop lithium immediately and arrange urgent lithium level (Correct Answer)
D. Continue lithium and start domperidone for symptom control
E. Switch to sodium valproate and monitor lithium level

Explanation: ***Stop lithium immediately and arrange urgent lithium level*** - The patient presents with clear signs of **lithium toxicity**, including a **coarse tremor** and clinical **dehydration**, precipitated by a **gastrointestinal infection** causing fluid loss. - Dehydration significantly impairs renal lithium excretion, leading to rapid accumulation and potentially dangerous **elevated plasma levels** that require immediate cessation and urgent monitoring. *Continue lithium and arrange lithium level within 7 days* - Continuing lithium in a patient with active **signs of toxicity** and **volume depletion** is extremely dangerous and risks escalating to severe toxicity, including **seizures** or **renal damage**. - Waiting 7 days for a lithium level is an unacceptably slow response given the acute and potentially life-threatening nature of **lithium overdose** in a dehydrated state. *Reduce lithium dose by 50% and recheck level in 1 week* - A **dose reduction** is insufficient as the patient is already displaying signs of **acute lithium toxicity** due to increased reabsorption from dehydration, meaning even a reduced dose would likely remain toxic. - The immediate priority is to stop the accumulation and facilitate excretion of the already elevated lithium; merely reducing the dose does not address the **acute toxic state** or the physiological changes causing it. *Continue lithium and start domperidone for symptom control* - **Domperidone** would only address the vomiting symptom, while completely ignoring the critical issue of **lithium accumulation** and ongoing toxicity exacerbated by dehydration. - This approach risks masking worsening symptoms and allowing the patient to progress toward **severe lithium toxicity** without appropriate intervention. *Switch to sodium valproate and monitor lithium level* - Switching to an alternative mood stabilizer like **sodium valproate** does not address the immediate medical emergency of **acute lithium toxicity** and its existing high levels in the patient's system. - The primary concern is to manage and clear the currently elevated and **renally-excreted lithium**, not to initiate a new mood stabilizer in an acutely unwell patient.

Question 167: A 63-year-old woman with metastatic breast cancer is started on enoxaparin for prophylaxis of venous thromboembolism. She has a past medical history of hypertension and stage 3 chronic kidney disease with eGFR of 35 ml/min/1.73m². Her weight is 55 kg. According to current prescribing guidance, what adjustment should be made to the standard dose of enoxaparin?

A. No dose adjustment required
B. Reduce dose by 25% and monitor anti-Xa levels
C. Reduce dose by 50% and monitor anti-Xa levels (Correct Answer)
D. Switch to unfractionated heparin instead
E. Increase dosing interval from once to twice daily

Explanation: ***Reduce dose by 50% and monitor anti-Xa levels*** - **Enoxaparin**, a low molecular weight heparin, is primarily cleared by the **kidneys**. With an **eGFR of 35 ml/min/1.73m² (Stage 3 CKD)** and **low body weight (55 kg)**, there is a high risk of drug accumulation. - Current guidelines recommend a **50% dose reduction** for VTE prophylaxis in patients with an eGFR below 30 mL/min or those with an eGFR between 30-50 mL/min who also have additional risk factors like low body weight, along with monitoring **anti-Xa levels**. *No dose adjustment required* - This patient's **Stage 3 CKD (eGFR 35 ml/min/1.73m²)** significantly impairs enoxaparin clearance, and her **low body weight (55 kg)** further increases the risk of accumulation. - Standard dosing without adjustment would lead to **toxic accumulation** and a substantially elevated risk of **bleeding**, which is unacceptable for anticoagulation. *Reduce dose by 25% and monitor anti-Xa levels* - A **25% dose reduction** is generally considered insufficient to adequately mitigate the risk of **enoxaparin accumulation** in patients with significant renal impairment and low body weight. - Pharmacokinetic data and clinical experience indicate that a more substantial reduction, typically **50%**, is necessary to maintain safe and effective **anti-Xa levels** for prophylaxis in this high-risk group. *Switch to unfractionated heparin instead* - While **unfractionated heparin (UFH)** is often preferred in cases of **severe renal failure (eGFR <15 ml/min)** due to its non-renal clearance, it is not strictly necessary for Stage 3 CKD where LMWH can be adjusted. - **UFH** requires more frequent monitoring via **aPTT** and has a shorter half-life, making it less practical for VTE prophylaxis compared to appropriately dose-adjusted enoxaparin. *Increase dosing interval from once to twice daily* - Increasing the frequency of administration from once to **twice daily** without reducing the individual dose would inadvertently **increase the total daily drug exposure**. - This would exacerbate the problem of **drug accumulation** in a renally impaired patient, significantly increasing the risk of **hemorrhagic complications**, rather than providing a safer regimen.

Question 168: A 63-year-old man with type 2 diabetes is established on a complex insulin regimen comprising insulin glargine 38 units at 22:00, insulin aspart 12 units with breakfast, 10 units with lunch, and 14 units with evening meal. He is admitted with acute pancreatitis and made nil by mouth, and a variable rate intravenous insulin infusion (VRIII) is commenced at 09:00 on Monday. His last dose of insulin glargine was at 22:00 on Sunday night. He improves and is ready to resume eating at 18:00 on Wednesday. When is the most appropriate time to discontinue the VRIII?

A. Discontinue VRIII immediately at 18:00 Wednesday and give insulin aspart 14 units with the evening meal
B. Discontinue VRIII at 19:00 Wednesday, 1 hour after insulin aspart 14 units given with evening meal
C. Discontinue VRIII at 22:00 Wednesday when insulin glargine is administered
D. Discontinue VRIII at 23:00 Wednesday, 1 hour after insulin glargine is administered (Correct Answer)
E. Continue VRIII overnight and discontinue at 07:00 Thursday before breakfast insulin aspart

Explanation: ***Discontinue VRIII at 23:00 Wednesday, 1 hour after insulin glargine is administered*** - To safely transition from a **Variable Rate Intravenous Insulin Infusion (VRIII)**, there must be adequate **overlap** with **long-acting basal insulin** to prevent a gap in insulin coverage and subsequent **hyperglycemia** or **ketogenesis**. - **Insulin glargine** has a delayed onset of action, typically taking 1-2 hours to reach therapeutic levels; therefore, the VRIII should continue for at least **30-60 minutes after** the basal insulin is administered to ensure continuous insulinization. *Discontinue VRIII immediately at 18:00 Wednesday and give insulin aspart 14 units with the evening meal* - Stopping the **VRIII** immediately at 18:00 would leave the patient without effective insulin coverage, as **intravenous insulin** has a very short half-life. - **Insulin aspart** is a rapid-acting bolus insulin for meal coverage and does not provide the essential **basal insulin** required for continuous glycemic control. *Discontinue VRIII at 19:00 Wednesday, 1 hour after insulin aspart 14 units given with evening meal* - While providing a 1-hour overlap, this option fails to re-establish **basal insulin** coverage, as **insulin aspart** is a rapid-acting mealtime insulin. - The patient would be without crucial **basal insulin** from 19:00 until the glargine dose at 22:00, risking significant **hyperglycemia** and **ketosis** overnight. *Discontinue VRIII at 22:00 Wednesday when insulin glargine is administered* - **Insulin glargine** requires time to be absorbed and exert its therapeutic effect (onset of 1-2 hours after subcutaneous injection). - Discontinuing the **VRIII** at the exact moment of glargine administration would create a **therapeutic gap** where the patient has no active insulin, leading to potential metabolic instability. *Continue VRIII overnight and discontinue at 07:00 Thursday before breakfast insulin aspart* - This approach is overly cautious and prolongs the use of **intravenous insulin**, increasing the risk of **hypoglycemia** and complications related to IV access. - Once **basal insulin** is restarted with appropriate overlap, the **VRIII** is no longer needed, making continuation until Thursday morning unnecessary.

Question 169: A 77-year-old man with atrial fibrillation and a mechanical mitral valve replacement is on warfarin with target INR 3.0-4.0. He requires urgent colonoscopy for suspected lower gastrointestinal bleeding (haemoglobin dropped from 125 to 95 g/L over 48 hours with melaena). His current INR is 3.6. He is haemodynamically stable. What is the most appropriate anticoagulation management strategy prior to the procedure?

A. Give prothrombin complex concentrate and proceed with colonoscopy immediately
B. Give intravenous vitamin K 5-10mg and proceed when INR falls below 1.5
C. Omit warfarin doses and proceed with colonoscopy when INR falls to 1.5-2.0 (Correct Answer)
D. Continue warfarin and proceed with colonoscopy as INR is within therapeutic range
E. Give oral vitamin K 1-2mg and proceed when INR falls below 2.0

Explanation: ***Omit warfarin doses and proceed with colonoscopy when INR falls to 1.5-2.0***- In a **haemodynamically stable** patient with a high thromboembolic risk (**mechanical mitral valve**), omitting doses allows for a controlled drop in INR to a safer range for endoscopy.- An **INR of 1.5-2.0** provides a necessary balance, reducing the risk of procedural bleeding while minimizing the time the patient is unprotected from valve thrombosis.*Give prothrombin complex concentrate and proceed with colonoscopy immediately*- **Prothrombin complex concentrate (PCC)** is reserved for **life-threatening bleeding** or emergency surgery, which is not indicated here as the patient is stable.- Rapid reversal with PCC can be pro-thrombotic and is dangerous for patients with **mechanical heart valves** unless absolutely necessary.*Give intravenous vitamin K 5-10mg and proceed when INR falls below 1.5*- High-dose **intravenous Vitamin K** can cause **warfarin resistance** for several days, making it difficult to restart therapeutic anticoagulation after the procedure.- Aiming for an **INR below 1.5** unnecessarily increases the duration of subtherapeutic coverage in a patient with a high-risk **mitral prosthesis**.*Continue warfarin and proceed with colonoscopy as INR is within therapeutic range*- Performing a colonoscopy for **GI bleeding** with an **INR of 3.6** carries an unacceptably high risk of exacerbating the bleed or causing procedural complications.- Most endoscopic interventions require the INR to be significantly lower than the **therapeutic range** for a mechanical valve to ensure haemostasis.*Give oral vitamin K 1-2mg and proceed when INR falls below 2.0*- While lower doses of **oral Vitamin K** are safer than IV, they are still generally unnecessary in a **haemodynamically stable** patient when simple omission of doses is an option.- Managing the INR through **natural decay** (omission) allows for more predictable re-titration of warfarin once the bleeding source is identified and treated.

Question 170: A 42-year-old woman with newly diagnosed type 1 diabetes is being established on a basal-bolus insulin regimen. Over the past week, her pre-meal and bedtime capillary glucose readings have been: breakfast 6.2-7.8 mmol/L, lunch 11.5-14.2 mmol/L, evening meal 7.1-8.9 mmol/L, bedtime 9.8-12.4 mmol/L. She is currently on insulin detemir 18 units at bedtime and insulin lispro 6 units before each meal. Which insulin adjustment would most appropriately address her glucose pattern?

A. Increase insulin detemir to 22 units at bedtime
B. Increase breakfast insulin lispro to 8 units (Correct Answer)
C. Increase lunch insulin lispro to 8 units
D. Increase evening meal insulin lispro to 8 units
E. Split insulin detemir to 10 units in the morning and 10 units at bedtime

Explanation: ***Increase breakfast insulin lispro to 8 units*** - The patient's **pre-lunch glucose readings (11.5-14.2 mmol/L)** are significantly elevated, indicating that the current **breakfast bolus insulin (lispro)** is insufficient to cover the carbohydrate intake from breakfast. - In a basal-bolus regimen, the rapid-acting insulin given before a meal is primarily responsible for controlling the **postprandial glucose excursion** and ensuring an appropriate glucose level before the subsequent meal. *Increase insulin detemir to 22 units at bedtime* - Increasing the **basal insulin (detemir)** primarily impacts the **fasting glucose** (pre-breakfast readings), which are currently within an acceptable range (6.2-7.8 mmol/L). - Adjusting basal insulin when fasting levels are well-controlled risks **nocturnal hypoglycemia** without addressing the specific post-breakfast hyperglycemia. *Increase lunch insulin lispro to 8 units* - Increasing the **lunch bolus insulin** would primarily affect the glucose levels before the **evening meal**, which are already acceptable (7.1-8.9 mmol/L). - This adjustment would not target the elevated glucose readings observed **before lunch**, which is the main problem area. *Increase evening meal insulin lispro to 8 units* - While bedtime glucose is slightly high (9.8-12.4 mmol/L), the most pronounced and concerning hyperglycemia is seen **before lunch**, which should be prioritized for intervention. - Increasing the evening bolus without addressing the morning issue could lead to inadequate daytime control and potentially mask the primary problem. *Split insulin detemir to 10 units in the morning and 10 units at bedtime* - Splitting the **basal insulin dose** can improve overall 24-hour glucose stability by providing more even coverage, but it does not directly address **postprandial spikes** related to specific meals. - This adjustment would not specifically correct the **insulin-to-carbohydrate ratio mismatch** identified after breakfast.

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