Safe Prescribing — MCQs
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A 54-year-old woman with rheumatoid arthritis has been taking methotrexate 20mg once weekly for 18 months with good disease control. She now presents with mouth ulcers, sore throat, and fever. Blood tests show: Hb 89 g/L, WCC 1.2 × 10⁹/L, neutrophils 0.3 × 10⁹/L, platelets 45 × 10⁹/L. What is the most important immediate action regarding her methotrexate therapy?
A 67-year-old woman with permanent atrial fibrillation on apixaban 5mg twice daily is admitted with an acute ischaemic stroke (NIHSS score 16). CT brain shows no haemorrhage. She last took apixaban 6 hours ago. Thrombolysis is being considered. According to current UK stroke guidelines, what is the most appropriate management regarding her anticoagulation?
A 48-year-old man with type 2 diabetes is on insulin detemir 28 units at bedtime and insulin aspart with meals. He reports recurrent episodes of nocturnal hypoglycaemia at 03:00 but normal pre-breakfast readings. His bedtime glucose is typically 8-10 mmol/L. What is the most appropriate adjustment to his insulin regimen?
A 56-year-old woman with newly diagnosed deep vein thrombosis is commenced on treatment dose enoxaparin. She weighs 68kg and has normal renal function (eGFR 82 ml/min/1.73m²). According to current guidelines, which enoxaparin dosing regimen is most appropriate for this patient?
A 59-year-old woman with atrial fibrillation is on dabigatran 150mg twice daily. She requires urgent surgery for a fractured hip following a fall. The last dose of dabigatran was taken 14 hours ago. Her renal function shows eGFR 48 ml/min/1.73m². The orthopaedic team plans surgery in 6 hours. Considering dabigatran's pharmacokinetics and the patient's renal function, what is the most appropriate perioperative management?
A 52-year-old man with type 1 diabetes for 15 years attends the emergency department with altered consciousness. His wife reports he has been increasingly confused over the past hour. Capillary blood glucose is 1.9 mmol/L. He is agitated and combative, refusing oral treatment. Intravenous access cannot be established despite multiple attempts. Intramuscular glucagon 1mg is administered. After 15 minutes, he remains confused with blood glucose now 2.8 mmol/L. Analysing this response to treatment, what is the most likely explanation for the suboptimal response to glucagon?
A 73-year-old man with atrial fibrillation is on warfarin (target INR 2-3). He has been stable for 2 years with INR results consistently between 2.0-3.0. He now requires a tooth extraction. His most recent INR taken yesterday was 2.4. According to guidance on managing dental procedures in anticoagulated patients, what is the most appropriate perioperative anticoagulation management?
A 64-year-old man with mechanical mitral valve replacement is established on warfarin with target INR 2.5-3.5. He requires emergency laparotomy for perforated diverticulitis. His current INR is 3.2. The surgical team requests immediate reversal of anticoagulation. Understanding the risks and benefits in this scenario, what is the most appropriate management to balance surgical haemostasis and thrombotic risk?
A 56-year-old man with type 2 diabetes is on basal-bolus insulin therapy (insulin degludec 36 units at bedtime, insulin aspart 10 units with meals). He is admitted for elective inguinal hernia repair under general anaesthetic, scheduled as the first case at 08:00. He takes his usual insulin degludec at 22:00 the night before. What is the most appropriate management of his insulin on the day of surgery?
A 67-year-old woman with deep vein thrombosis completed 21 days of rivaroxaban 15mg twice daily and is now on maintenance rivaroxaban 20mg once daily. She develops significant epistaxis requiring ENT input and nasal packing. Her haemoglobin drops from 128 g/L to 94 g/L. Rivaroxaban was last taken 8 hours ago. Understanding the pharmacokinetics of rivaroxaban, which statement best explains the approach to reversal in major bleeding?
Safe Prescribing UK Medical PG Practice Questions and MCQs
Question 11: A 54-year-old woman with rheumatoid arthritis has been taking methotrexate 20mg once weekly for 18 months with good disease control. She now presents with mouth ulcers, sore throat, and fever. Blood tests show: Hb 89 g/L, WCC 1.2 × 10⁹/L, neutrophils 0.3 × 10⁹/L, platelets 45 × 10⁹/L. What is the most important immediate action regarding her methotrexate therapy?
- A. Stop methotrexate immediately and commence folinic acid rescue (Correct Answer)
- B. Continue methotrexate but reduce dose to 15mg weekly
- C. Stop methotrexate temporarily until blood counts recover, then restart at same dose
- D. Stop methotrexate permanently and never restart
- E. Continue methotrexate but increase folic acid supplementation
Explanation: ***Stop methotrexate immediately and commence folinic acid rescue*** - The patient's symptoms (mouth ulcers, sore throat, fever) coupled with severe pancytopenia (low Hb, WCC, neutrophils, platelets) indicate **severe methotrexate toxicity** and **neutropenic sepsis**. - Immediate cessation of methotrexate and administration of **folinic acid (leucovorin)** is crucial to rapidly reverse the effects of methotrexate on folate metabolism and prevent further bone marrow suppression. *Continue methotrexate but reduce dose to 15mg weekly* - Continuing methotrexate, even at a reduced dose, is highly dangerous and contraindicated in the presence of severe **bone marrow suppression** and suspected **neutropenic sepsis**. - Dose reduction is not an appropriate immediate action when the patient is experiencing life-threatening toxicity; complete cessation is required. *Stop methotrexate temporarily until blood counts recover, then restart at same dose* - While stopping methotrexate is correct, simply waiting for blood counts to recover without **folinic acid rescue** is insufficient for severe toxicity and could lead to worse outcomes. - Restarting at the same dose after such a severe adverse event without a thorough investigation into the cause (e.g., renal impairment, drug interactions) is unsafe and could lead to recurrence. *Stop methotrexate permanently and never restart* - Permanent cessation of methotrexate is a decision typically made after the acute toxicity has been managed and the patient's condition has stabilized, following specialist review. - The most important *immediate* action is to address the acute, life-threatening toxicity with cessation and **folinic acid rescue**, rather than a long-term prescribing decision. *Continue methotrexate but increase folic acid supplementation* - **Folic acid** is a precursor that needs to be converted to active forms and is generally used for routine prophylaxis to reduce side effects, not to treat acute, severe toxicity. - In severe methotrexate toxicity, the enzyme **dihydrofolate reductase** is inhibited; therefore, direct administration of **folinic acid** (an active form of folate) is required to bypass this inhibition and rescue cells.
Question 12: A 67-year-old woman with permanent atrial fibrillation on apixaban 5mg twice daily is admitted with an acute ischaemic stroke (NIHSS score 16). CT brain shows no haemorrhage. She last took apixaban 6 hours ago. Thrombolysis is being considered. According to current UK stroke guidelines, what is the most appropriate management regarding her anticoagulation?
- A. Proceed with thrombolysis; apixaban does not contraindicate treatment
- B. Withhold thrombolysis; wait 24 hours from last apixaban dose before considering
- C. Check anti-Xa level; proceed with thrombolysis if undetectable (Correct Answer)
- D. Reverse apixaban with idarucizumab, then proceed with thrombolysis
- E. Check APTT; proceed with thrombolysis if APTT is normal
Explanation: ***Check anti-Xa level; proceed with thrombolysis if undetectable*** - UK stroke guidelines recommend measuring **anti-Xa levels** for patients on Factor Xa inhibitors (like apixaban) who present within the thrombolytic window. - Thrombolysis can be considered if the **anti-Xa level is undetectable** or below a specific threshold, indicating a low residual anticoagulant effect and reduced bleeding risk. *Proceed with thrombolysis; apixaban does not contraindicate treatment* - Current therapeutic anticoagulation with a **DOAC** is a major contraindication to **intravenous thrombolysis** due to a significantly increased risk of intracranial haemorrhage. - Thrombolysis is only safe to proceed if there is objective evidence that the anticoagulant effect is **clinically insignificant**. *Withhold thrombolysis; wait 24 hours from last apixaban dose before considering* - A blanket **24-hour waiting period** after the last DOAC dose is not universally recommended as it can delay potentially life-saving treatment. - Individual drug clearance varies, and specific **laboratory tests** provide a more accurate and timely assessment of residual anticoagulant activity. *Reverse apixaban with idarucizumab, then proceed with thrombolysis* - **Idarucizumab** is a specific reversal agent for **dabigatran** (a direct thrombin inhibitor), not for apixaban. - Apixaban is a Factor Xa inhibitor, and its specific reversal agent is **andexanet alfa**, which is not routinely recommended prior to thrombolysis. *Check APTT; proceed with thrombolysis if APTT is normal* - The **Activated Partial Thromboplastin Time (APTT)** is not a reliable measure of the anticoagulant effect of **Factor Xa inhibitors** like apixaban. - While apixaban might slightly prolong APTT, this test is not sensitive or specific enough to guide decisions for thrombolysis in patients on this medication.
Question 13: A 48-year-old man with type 2 diabetes is on insulin detemir 28 units at bedtime and insulin aspart with meals. He reports recurrent episodes of nocturnal hypoglycaemia at 03:00 but normal pre-breakfast readings. His bedtime glucose is typically 8-10 mmol/L. What is the most appropriate adjustment to his insulin regimen?
- A. Reduce evening insulin detemir dose by 10-20% (Correct Answer)
- B. Increase evening insulin detemir dose by 10-20%
- C. Reduce lunchtime insulin aspart dose
- D. Give insulin detemir in the morning instead of evening
- E. Add a bedtime snack containing complex carbohydrates
Explanation: ***Reduce evening insulin detemir dose by 10-20%*** - The patient's **nocturnal hypoglycaemia** at 03:00 directly indicates that the effect of the bedtime **basal insulin** (detemir) is excessive during the early morning hours. - Reducing the dose of **insulin detemir** will lower the basal insulin coverage, effectively preventing these hypoglycaemic episodes without compromising morning glucose levels, which are currently normal. *Increase evening insulin detemir dose by 10-20%* - Increasing the **insulin detemir** dose would further exacerbate the existing **nocturnal hypoglycaemia**, leading to more severe or frequent episodes. - This adjustment would only be considered if the patient was experiencing persistently high blood glucose levels during the night, not hypoglycemia. *Reduce lunchtime insulin aspart dose* - **Insulin aspart** is a rapid-acting insulin designed to cover glucose excursions after meals; its effect is transient. - A lunchtime dose of insulin aspart would have no impact on blood glucose levels at 03:00 the following morning, making this an inappropriate adjustment for nocturnal hypoglycemia. *Give insulin detemir in the morning instead of evening* - While **insulin detemir** can be given in the morning, simply changing the administration time without a dose adjustment might not resolve the underlying problem of insulin excess at night and could lead to inadequate basal coverage later in the day or evening. - The immediate priority is addressing the **insulin over-effect** causing hypoglycemia, which is best achieved by reducing the dose rather than just altering timing. *Add a bedtime snack containing complex carbohydrates* - Adding a **bedtime snack** can temporarily raise blood glucose, but it is a compensatory measure for an inappropriately high insulin dose and often contributes to unwanted **weight gain** in type 2 diabetes. - The preferred approach is to optimize the **insulin regimen** to match physiological needs rather than introducing additional calories to counteract excessive insulin.
Question 14: A 56-year-old woman with newly diagnosed deep vein thrombosis is commenced on treatment dose enoxaparin. She weighs 68kg and has normal renal function (eGFR 82 ml/min/1.73m²). According to current guidelines, which enoxaparin dosing regimen is most appropriate for this patient?
- A. 1mg/kg subcutaneously twice daily
- B. 1.5mg/kg subcutaneously once daily (Correct Answer)
- C. 40mg subcutaneously once daily
- D. 0.5mg/kg subcutaneously twice daily
- E. 60mg subcutaneously twice daily fixed dose
Explanation: ***1.5mg/kg subcutaneously once daily*** - For the treatment of **Deep Vein Thrombosis (DVT)** in patients with normal renal function, the preferred treatment dose according to guidelines is **1.5mg/kg once daily** or 1mg/kg twice daily.- This patient has an **eGFR of 82 ml/min**, meaning dose reduction for **renal impairment** (usually required when eGFR <30) is not necessary.*1mg/kg subcutaneously twice daily* - This is an acceptable **therapeutic dose** for VTE; however, once-daily dosing at **1.5mg/kg** is often preferred for uncomplicated DVT due to better **patient compliance**.- This regimen is typically reserved for patients with a higher risk of thrombosis or certain complications, but it is not the singularly "most appropriate" first-line choice over the 1.5mg/kg once-daily option in this context.*40mg subcutaneously once daily* - This is the standard **prophylactic dose** used for VTE prevention in surgical or immobilized medical patients.- It is insufficient for the **treatment** of an established deep vein thrombosis, which requires higher, **weight-adjusted** weight doses.*0.5mg/kg subcutaneously twice daily* - This is a sub-therapeutic frequency and dosage for the active treatment of **venous thromboembolism**.- It does not align with established **pharmacokinetic guidelines** for achieving effective anticoagulation levels with Enoxaparin.*60mg subcutaneously twice daily fixed dose* - Therapeutic enoxaparin dosing must be **weight-adjusted** (mg/kg) rather than fixed-dose to ensure safety and efficacy.- A fixed dose of 60mg twice daily would result in **inaccurate dosing** for this 68kg patient, who requires approximately 102mg (if once daily) or 68mg (if twice daily).
Question 15: A 59-year-old woman with atrial fibrillation is on dabigatran 150mg twice daily. She requires urgent surgery for a fractured hip following a fall. The last dose of dabigatran was taken 14 hours ago. Her renal function shows eGFR 48 ml/min/1.73m². The orthopaedic team plans surgery in 6 hours. Considering dabigatran's pharmacokinetics and the patient's renal function, what is the most appropriate perioperative management?
- A. Delay surgery until at least 48 hours after the last dabigatran dose given the impaired renal function, as dabigatran has significant renal elimination
- B. Proceed to surgery as planned; 14 hours is insufficient clearance time but emergency surgery necessitates accepting increased bleeding risk with local haemostatic measures
- C. Administer idarucizumab 5g intravenously immediately to reverse dabigatran and proceed to surgery (Correct Answer)
- D. Measure anti-Xa levels to guide decision on timing of surgery
- E. Give prothrombin complex concentrate (PCC) before surgery to reduce bleeding risk
Explanation: ***Administer idarucizumab 5g intravenously immediately to reverse dabigatran and proceed to surgery***- **Idarucizumab** is a specific humanized monoclonal antibody fragment that provides **immediate and complete reversal** of dabigatran's anticoagulant effect within minutes.- Since the patient requires **urgent surgery** for a fractured hip and has **impaired renal function (eGFR 48)** which slows dabigatran clearance, drug reversal is essential to prevent life-threatening perioperative hemorrhage.*Delay surgery until at least 48 hours after the last dabigatran dose given the impaired renal function, as dabigatran has significant renal elimination*- While **48-72 hours** is the recommended wait time for major surgery with this eGFR, delaying hip fracture surgery significantly increases **morbidity and mortality**.- Hip fractures are considered **time-sensitive** emergencies where clinical outcomes are better if addressed within 24-48 hours.*Proceed to surgery as planned; 14 hours is insufficient clearance time but emergency surgery necessitates accepting increased bleeding risk with local haemostatic measures*- Proceeding without reversal carries an unacceptably high **risk of major bleeding**, as dabigatran is a potent **direct thrombin inhibitor**.- Local measures are often insufficient for deep tissue surgeries like hip repair when systemic anticoagulation is at near-therapeutic levels.*Measure anti-Xa levels to guide decision on timing of surgery*- **Anti-Xa assays** are used to monitor factor Xa inhibitors (like rivaroxaban or apixaban) and are completely ineffective for monitoring **dabigatran**.- Dabigatran is a **direct thrombin inhibitor**, so its effect would be better reflected by a **diluted thrombin time (dTT)** or ecarin clotting time, though these shouldn't delay urgent reversal.*Give prothrombin complex concentrate (PCC) before surgery to reduce bleeding risk*- **PCC** is used as a reversal agent for Vitamin K antagonists or factor Xa inhibitors but has **limited and inconsistent efficacy** against dabigatran.- Specific reversal with **idarucizumab** is the first-line gold standard for dabigatran; PCC should only be considered if the specific antidote is unavailable.
Question 16: A 52-year-old man with type 1 diabetes for 15 years attends the emergency department with altered consciousness. His wife reports he has been increasingly confused over the past hour. Capillary blood glucose is 1.9 mmol/L. He is agitated and combative, refusing oral treatment. Intravenous access cannot be established despite multiple attempts. Intramuscular glucagon 1mg is administered. After 15 minutes, he remains confused with blood glucose now 2.8 mmol/L. Analysing this response to treatment, what is the most likely explanation for the suboptimal response to glucagon?
- A. Depleted hepatic glycogen stores due to prolonged fasting, alcohol excess, or chronic malnutrition limit the glucose release in response to glucagon (Correct Answer)
- B. Glucagon was administered subcutaneously rather than intramuscularly, delaying absorption
- C. The patient has developed glucagon resistance due to long-standing type 1 diabetes
- D. An insufficient dose of glucagon was given; the correct dose for adults is 2mg intramuscularly
- E. Hypoglycaemia has been present for too long, and irreversible neurological damage has occurred
Explanation: ***Depleted hepatic glycogen stores due to prolonged fasting, alcohol excess, or chronic malnutrition limit the glucose release in response to glucagon***- **Glucagon** works primarily by stimulating **hepatic glycogenolysis**; if glycogen stores are exhausted, the hormonal stimulus cannot effectively raise blood glucose.- Clinical conditions such as **chronic malnutrition**, **alcohol excess**, or **starvation** are classic scenarios where glucagon becomes ineffective for treating **hypoglycaemia**.*Glucagon was administered subcutaneously rather than intramuscularly, delaying absorption*- While **subcutaneous** administration might slightly delay the peak effect, it would not typically cause a complete **blunting of the glycemic response** observed in 15 minutes.- **Pharmacokinetic** differences between IM and SC glucagon are generally not clinically significant enough to explain a failure of glucose recovery in an emergency.*The patient has developed glucagon resistance due to long-standing type 1 diabetes*- **Glucagon resistance** is not a recognised pathological feature of **type 1 diabetes**; the liver remains sensitive to exogenous glucagon stimulus for glucose release.- Long-standing diabetes actually causes a loss of the **endogenous glucagon response** to hypoglycaemia, making exogenous administration more critical, not less effective.*An insufficient dose of glucagon was given; the correct dose for adults is 2mg intramuscularly*- The standard, universally recommended dose of **intramuscular glucagon** for the emergency reversal of hypoglycaemia in adults is **1mg**.- Administering **2mg** is not the standard of care and would unlikely rectify a failure caused by the absence of **hepatic glycogen substrate**.*Hypoglycaemia has been present for too long, and irreversible neurological damage has occurred*- A blood glucose rise from 1.9 to 2.8 mmol/L is a **biochemical failure** of the medication, which points to metabolic issues rather than the duration of the coma.- **Irreversible neurological damage** would not prevent the blood glucose level from rising; it would only prevent the clinical recovery of **consciousness** despite normalisation of glucose.
Question 17: A 73-year-old man with atrial fibrillation is on warfarin (target INR 2-3). He has been stable for 2 years with INR results consistently between 2.0-3.0. He now requires a tooth extraction. His most recent INR taken yesterday was 2.4. According to guidance on managing dental procedures in anticoagulated patients, what is the most appropriate perioperative anticoagulation management?
- A. Proceed with dental extraction without stopping warfarin, ensuring INR is <4.0 on the day of procedure, and arrange local haemostatic measures (Correct Answer)
- B. Stop warfarin 5 days before procedure, start low molecular weight heparin (LMWH) bridging therapy, and restart warfarin after the procedure
- C. Stop warfarin 2 days before procedure, check INR is <1.5 before proceeding, and restart warfarin the evening of the procedure
- D. Give prothrombin complex concentrate on the day of the procedure to temporarily reverse anticoagulation
- E. Stop warfarin 3 days before procedure and do not restart until dental socket has completely healed
Explanation: ***Proceed with dental extraction without stopping warfarin, ensuring INR is <4.0 on the day of procedure, and arrange local haemostatic measures*** - For minor dental procedures like **tooth extraction**, current guidelines recommend continuing **warfarin** if the **INR is less than 4.0** (or sometimes 3.5), which is met by the patient's INR of 2.4. - This approach minimizes the risk of **thromboembolic events** (e.g., stroke in atrial fibrillation) while managing minor bleeding risks with **local haemostatic measures** such as suturing, pressure, or tranexamic acid mouthwash. *Stop warfarin 5 days before procedure, start low molecular weight heparin (LMWH) bridging therapy, and restart warfarin after the procedure* - **Bridging therapy** with LMWH is generally not indicated for low-risk procedures like tooth extraction and significantly increases the risk of **post-operative bleeding**. - This strategy is reserved for patients at very high **thrombotic risk** undergoing major surgeries, which is not the scenario here. *Stop warfarin 2 days before procedure, check INR is <1.5 before proceeding, and restart warfarin the evening of the procedure* - Stopping **warfarin** for two days puts the patient with **atrial fibrillation** at an unnecessary and increased risk of a **thromboembolic stroke** due to subtherapeutic anticoagulation. - Minor dental procedures can be safely performed within the therapeutic INR range (2.0-3.0), and severe bleeding is rare and manageable with local measures. *Give prothrombin complex concentrate on the day of the procedure to temporarily reverse anticoagulation* - **Prothrombin complex concentrate (PCC)** is reserved for rapid reversal of **warfarin** in cases of life-threatening bleeding or major emergency surgery, not for elective minor procedures. - Administering PCC unnecessarily carries a significant risk of **acute thrombosis** and is an inappropriate intervention for this clinical context. *Stop warfarin 3 days before procedure and do not restart until dental socket has completely healed* - Prolonged interruption of **warfarin** until complete healing would leave the patient unprotected against **thromboembolic events** for an extended period, substantially increasing the risk of **ischaemic stroke**. - Guidelines advocate against routine interruption of warfarin for procedures with a low **bleeding risk**, relying on local haemostatic measures instead of prolonged systemic anticoagulation cessation.
Question 18: A 64-year-old man with mechanical mitral valve replacement is established on warfarin with target INR 2.5-3.5. He requires emergency laparotomy for perforated diverticulitis. His current INR is 3.2. The surgical team requests immediate reversal of anticoagulation. Understanding the risks and benefits in this scenario, what is the most appropriate management to balance surgical haemostasis and thrombotic risk?
- A. Give prothrombin complex concentrate (PCC) 25-50 units/kg and intravenous vitamin K 5mg to achieve rapid reversal; restart anticoagulation with low molecular weight heparin (LMWH) postoperatively as soon as haemostasis allows (Correct Answer)
- B. Give fresh frozen plasma (FFP) 15ml/kg alone without vitamin K to allow easier re-anticoagulation postoperatively
- C. Withhold warfarin and proceed to surgery without any reversal agent given INR is only mildly elevated
- D. Give oral vitamin K 10mg and delay surgery for 24 hours to allow gradual INR reduction
- E. Give intravenous vitamin K 10mg alone and proceed to surgery when INR falls below 2.0
Explanation: ***Give prothrombin complex concentrate (PCC) 25-50 units/kg and intravenous vitamin K 5mg to achieve rapid reversal; restart anticoagulation with low molecular weight heparin (LMWH) postoperatively as soon as haemostasis allows***- **Prothrombin complex concentrate (PCC)** is the treatment of choice for emergency warfarin reversal because it provides immediate replacement of **factors II, VII, IX, and X** without the volume overload associated with FFP.- **Intravenous vitamin K** is essential alongside PCC to promote the synthesis of new clotting factors and prevent an **INR rebound** once the exogenous PCC factors are metabolized.*Give fresh frozen plasma (FFP) 15ml/kg alone without vitamin K to allow easier re-anticoagulation postoperatively*- **FFP** is less effective than PCC because it requires large volumes, needs **ABO matching**, and takes significantly longer to correct the INR.- Omitting **Vitamin K** is dangerous in emergency surgery as the anticoagulation effect will return as soon as the transfused plasma factors degrade.*Withhold warfarin and proceed to surgery without any reversal agent given INR is only mildly elevated*- An **INR of 3.2** represents a significant bleeding risk for major abdominal surgery; proceeding without reversal would likely lead to uncontrollable **intraoperative hemorrhage**.- High-risk procedures like a **laparotomy** for perforated diverticulitis require an INR typically below 1.5 to ensure adequate surgical **hemostasis**.*Give oral vitamin K 10mg and delay surgery for 24 hours to allow gradual INR reduction*- **Oral vitamin K** acts too slowly (peaking at 12–24 hours) for an **emergency laparotomy** necessitated by perforated diverticulitis, which carries a high risk of sepsis.- Delaying surgery for 24 hours in the setting of a **perforated bowel** is clinically inappropriate and significantly increases patient mortality.*Give intravenous vitamin K 10mg alone and proceed to surgery when INR falls below 2.0*- While **IV vitamin K** works faster than oral, it still takes approximately 4–6 hours to begin correcting the INR, which is too slow for **immediate emergency reversal**.- Reversing to an INR of 2.0 is insufficient for major surgery, and relying on Vitamin K alone ignores the immediate need for **clotting factor replacement** provided by PCC.
Question 19: A 56-year-old man with type 2 diabetes is on basal-bolus insulin therapy (insulin degludec 36 units at bedtime, insulin aspart 10 units with meals). He is admitted for elective inguinal hernia repair under general anaesthetic, scheduled as the first case at 08:00. He takes his usual insulin degludec at 22:00 the night before. What is the most appropriate management of his insulin on the day of surgery?
- A. Omit morning insulin aspart, continue usual insulin degludec, start variable rate intravenous insulin infusion (VRIII) only if blood glucose >12 mmol/L or he misses more than one meal (Correct Answer)
- B. Stop all subcutaneous insulin and start variable rate intravenous insulin infusion (VRIII) from 06:00 on the morning of surgery
- C. Give usual insulin degludec at 22:00 the night before and usual insulin aspart with breakfast, then fast for 6 hours before surgery
- D. Give half the usual dose of both insulin degludec and insulin aspart on the morning of surgery
- E. Omit all insulin until after the surgery is completed, then resume usual regimen
Explanation: ***Omit morning insulin aspart, continue usual insulin degludec, start variable rate intravenous insulin infusion (VRIII) only if blood glucose >12 mmol/L or he misses more than one meal*** - For elective surgery as the first case, the patient is expected to have a short **fasting period**, likely missing only one meal. In this scenario, **basal insulin** (degludec) should be continued at the usual dose to prevent **ketoacidosis** and maintain metabolic stability. - **Prandial (bolus) insulin** (aspart) must be omitted while fasting to avoid severe **hypoglycaemia**. A **Variable Rate Intravenous Insulin Infusion (VRIII)** is only initiated if **blood glucose** levels exceed target (>12 mmol/L) or if the patient misses more than one meal. *Stop all subcutaneous insulin and start variable rate intravenous insulin infusion (VRIII) from 06:00 on the morning of surgery* - Stopping all **subcutaneous insulin**, including the basal dose, significantly increases the risk of **hyperglycemia** and **diabetic ketoacidosis (DKA)** in an insulin-dependent patient, especially if VRIII is delayed or inadequately managed. - Routine **VRIII** for a short, elective fasting period is generally **overmanagement**, carrying risks of **electrolyte imbalance** and requiring intensive monitoring that might not be necessary for simple procedures. *Give usual insulin degludec at 22:00 the night before and usual insulin aspart with breakfast, then fast for 6 hours before surgery* - Giving **insulin aspart** (rapid-acting mealtime insulin) with breakfast before surgery is strictly contraindicated as the patient will be **fasting (NPO)**, leading to profound **intraoperative hypoglycaemia**. - This approach violates fundamental **perioperative fasting guidelines** and poses a serious safety risk to the patient. *Give half the usual dose of both insulin degludec and insulin aspart on the morning of surgery* - Giving any dose of **insulin aspart** on the morning of surgery while fasting will predispose the patient to **hypoglycaemia**, as there is no meal to counteract its effect. - A blanket **reduction of basal insulin** (degludec) by half is often unnecessary for ultra-long-acting analogues in short fasting scenarios and may lead to inadequate **basal glucose control**, increasing the risk of hyperglycemia. *Omit all insulin until after the surgery is completed, then resume usual regimen* - **Omitting all insulin** in a patient on a basal-bolus regimen is highly dangerous, as it can rapidly lead to severe **hyperglycemia** and potentially **diabetic ketoacidosis (DKA)**, even in individuals with Type 2 diabetes under surgical stress. - Maintaining adequate **basal insulin** is essential throughout the perioperative period to prevent metabolic decompensation and ensure patient safety.
Question 20: A 67-year-old woman with deep vein thrombosis completed 21 days of rivaroxaban 15mg twice daily and is now on maintenance rivaroxaban 20mg once daily. She develops significant epistaxis requiring ENT input and nasal packing. Her haemoglobin drops from 128 g/L to 94 g/L. Rivaroxaban was last taken 8 hours ago. Understanding the pharmacokinetics of rivaroxaban, which statement best explains the approach to reversal in major bleeding?
- A. Rivaroxaban has a relatively short half-life (5-9 hours in elderly); supportive measures and withholding further doses may be sufficient, but if life-threatening bleeding, consider prothrombin complex concentrate (PCC) (Correct Answer)
- B. Immediate administration of vitamin K 10mg intravenously will rapidly reverse rivaroxaban's anticoagulant effect
- C. Protamine sulphate should be given urgently as the specific reversal agent for factor Xa inhibitors
- D. Andexanet alfa is routinely available in all UK hospitals and should be administered immediately
- E. Fresh frozen plasma (FFP) 15ml/kg is the first-line reversal agent for all DOAC-related bleeding
Explanation: ***Rivaroxaban has a relatively short half-life (5-9 hours in elderly); supportive measures and withholding further doses may be sufficient, but if life-threatening bleeding, consider prothrombin complex concentrate (PCC)***- **Rivaroxaban** is a direct **Factor Xa inhibitor** with a relatively short half-life, meaning drug levels decline significantly within 24 hours of the last dose, making withholding doses a primary strategy.- For major bleeding, the primary approach involves **mechanical compression**, **supportive care** (e.g., fluid resuscitation, blood transfusion), and potentially **4-factor PCC** to increase thrombin generation if bleeding is life-threatening or uncontrolled.*Immediate administration of vitamin K 10mg intravenously will rapidly reverse rivaroxaban's anticoagulant effect*- **Vitamin K** is the specific reversal agent for **Warfarin** (vitamin K antagonists) and has no effect on direct oral anticoagulants (DOACs) like rivaroxaban.- Rivaroxaban does not interfere with the **vitamin K cycle** or directly inhibit vitamin K-dependent clotting factors, rendering vitamin K ineffective.*Protamine sulphate should be given urgently as the specific reversal agent for factor Xa inhibitors*- **Protamine sulphate** is the reversal agent specifically for **Unfractionated Heparin** and partially for Low Molecular Weight Heparin.- It does not bind to or inhibit the action of direct **Factor Xa inhibitors** such as rivaroxaban, making it unsuitable for this type of bleeding.*Andexanet alfa is routinely available in all UK hospitals and should be administered immediately*- While **Andexanet alfa** is a specific decoy receptor for Factor Xa inhibitors, it is **not routinely available** in all UK hospitals due to its high cost and specific criteria for use.- It is typically reserved for **life-threatening gastrointestinal or intracranial bleeding**, rather than epistaxis that may respond to packing and other supportive measures.*Fresh frozen plasma (FFP) 15ml/kg is the first-line reversal agent for all DOAC-related bleeding*- **FFP** contains clotting factors in dilute concentrations and is **not effective** at reversing the potent inhibition of Factor Xa by DOACs.- Large volumes of FFP would be required to overcome the drug effect, risking **volume overload** and transfusion-related adverse events without providing reliable haemostasis.
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