Safe Prescribing

Safe Prescribing UK Medical PG Question 1: According to the Mental Capacity Act 2005, which of the following statements about the hierarchy of decision-makers for a patient lacking capacity is correct?

• A. Court-appointed deputy takes precedence over a registered Lasting Power of Attorney
• B. Valid advance decision to refuse treatment takes precedence over Lasting Power of Attorney for Health and Welfare (Correct Answer)
• C. Lasting Power of Attorney for Health and Welfare takes precedence over advance decisions
• D. Next of kin have legal authority to make treatment decisions if no LPA exists
• E. Independent Mental Capacity Advocate can make binding treatment decisions

Safe Prescribing Explanation: ***Valid advance decision to refuse treatment takes precedence over Lasting Power of Attorney for Health and Welfare*** - Under the **Mental Capacity Act 2005**, a valid and applicable **Advance Decision to Refuse Treatment (ADRT)** represents the patient's own autonomous choice and is legally binding on clinicians. - If an **ADRT** is made and is applicable to the current situation, a **Lasting Power of Attorney (LPA)** for Health and Welfare cannot override it unless the LPA was granted after the ADRT was signed and explicitly allows for such an override. *Court-appointed deputy takes precedence over a registered Lasting Power of Attorney* - A **Court-appointed Deputy** is typically assigned by the **Court of Protection** when no **LPA** is in place, or an existing LPA is deemed problematic or insufficient by the court. - An **LPA** is a direct appointment by the individual themselves when they have capacity, and generally holds authority in its designated areas over a subsequently appointed deputy for the same matters. *Lasting Power of Attorney for Health and Welfare takes precedence over advance decisions* - This statement is incorrect; a valid and applicable **Advance Decision to Refuse Treatment (ADRT)** generally takes precedence over a **Lasting Power of Attorney (LPA)** for Health and Welfare. - An **ADRT** is a direct expression of the individual's will regarding specific treatments, whereas an LPA appoints an attorney to make decisions in their best interests, which must respect any valid ADRT. *Next of kin have legal authority to make treatment decisions if no LPA exists* - In the UK, **Next of Kin** have no legal authority to consent to or refuse treatment for an adult who lacks capacity. - While their views must be considered as part of determining the patient's **best interests**, the final clinical decision remains with the **treating clinician** or a legally appointed representative. *Independent Mental Capacity Advocate can make binding treatment decisions* - An **Independent Mental Capacity Advocate (IMCA)** is appointed to support and represent individuals who lack capacity and have no family or friends to consult for serious decisions. - An **IMCA's role** is to provide an independent report to help the decision-maker determine the patient's **best interests**; they do not have the power to make binding medical decisions themselves.

Safe Prescribing UK Medical PG Question 2: An 82-year-old woman with severe dementia (MMSE 6/30) and recurrent urosepsis is admitted from a nursing home. She has no advance decision or LPA. Her son (only relative) says 'Mum always said if she got dementia she wouldn't want to be kept alive with antibiotics'. There is no documented evidence of this. She appears comfortable but has sepsis requiring IV antibiotics. What weight should be given to the son's account?

• A. No weight as there is no written advance decision to refuse treatment
• B. It should be determinative as he is the next of kin
• C. It forms part of the best interests assessment but is not binding (Correct Answer)
• D. It constitutes a valid oral advance decision and antibiotics should be withheld
• E. It should be ignored as the son may have ulterior motives

Safe Prescribing Explanation: ***It forms part of the best interests assessment but is not binding***- Under the **Mental Capacity Act 2005**, clinicians are legally required to consider the patient's **past wishes and feelings** when they lack capacity, which the son's testimony provides insight into.- While this information is crucial for a **holistic best interests assessment**, it is not legally binding as it does not meet the formal requirements of an **Advance Decision to Refuse Treatment** (ADRT). *No weight as there is no written advance decision to refuse treatment*- Medical professionals are legally obligated to consult with **relatives and friends** to ascertain the patient's past values and beliefs when the patient lacks capacity and no formal ADRT exists.- Ignoring the son's account would constitute a failure to properly conduct a **best interests assessment** by not considering all relevant information about the patient's potential preferences. *It should be determinative as he is the next of kin*- In UK law, being the **next of kin** does not confer legal authority to make medical decisions for an adult, unlike holding a **Lasting Power of Attorney (LPA)**.- The ultimate decision for an incapacitated patient without an LPA rests with the **healthcare team**, who must act in the patient's best interests after considering all relevant factors. *It constitutes a valid oral advance decision and antibiotics should be withheld*- An **Advance Decision to Refuse Treatment (ADRT)** concerning life-sustaining treatment must be **written, signed by the patient, and witnessed** to be legally valid and binding.- The son's report of verbal statements does not meet these strict **statutory criteria** for a legally enforceable ADRT to withhold life-saving antibiotics. *It should be ignored as the son may have ulterior motives*- It is professionally inappropriate and unethical to assume **ulterior motives** without clear evidence or specific concerns that warrant investigation.- The son's input, like that of other individuals who know the patient well, is a vital component of the **best interests assessment** and must be considered with due diligence.

Safe Prescribing UK Medical PG Question 3: A 28-year-old woman presents with a 3-day history of dysuria, urinary frequency, and suprapubic pain. She is otherwise well with no fever. Urine dipstick shows nitrites positive, leucocytes positive. What is the most appropriate first-line antibiotic treatment?

• A. Amoxicillin 500mg TDS for 7 days
• B. Trimethoprim 200mg BD for 3 days (Correct Answer)
• C. Ciprofloxacin 500mg BD for 7 days
• D. Nitrofurantoin 50mg QDS for 3 days
• E. Co-amoxiclav 625mg TDS for 7 days

Safe Prescribing Explanation: ***Trimethoprim 200mg BD for 3 days***- This is a standard, highly effective **short course** regimen (3 days) recommended for community-acquired, uncomplicated **cystitis** in non-pregnant women, provided local **E. coli** resistance rates are acceptable (typically <20%).- Short courses improve adherence and minimize **collateral damage** (disruption of normal flora) and secondary resistance compared to longer courses.*Amoxicillin 500mg TDS for 7 days*- Amoxicillin monotherapy is unsuitable as first-line treatment for UTIs due to extremely high rates of **E. coli resistance** globally and poor efficacy in many regions.- The 7-day duration is unnecessarily long for uncomplicated **cystitis**, increasing antibiotic exposure and the risk of adverse effects.*Ciprofloxacin 500mg BD for 7 days*- **Fluoroquinolones** (like Ciprofloxacin) are generally reserved for complicated UTIs, **pyelonephritis**, or cases where first-line agents fail, due to resistance concerns and potential serious side effects.- A 7-day course is excessive. Uncomplicated cystitis usually requires only 3–5 days of effective therapy; 7 days is more appropriate for treating **pyelonephritis**.*Nitrofurantoin 50mg QDS for 3 days*- **Nitrofurantoin** is a preferred first-line agent, but the standard recommended regimen is typically 100mg BD for 5 days (or 50mg QDS for 5–7 days).- While highly effective against E. coli, a 3-day course of Nitrofurantoin is less established compared to the standard 3-day course used for **Trimethoprim** for uncomplicated cystitis.*Co-amoxiclav 625mg TDS for 7 days*- **Co-amoxiclav** (Amoxicillin/Clavulanate) is not a first-line agent for uncomplicated cystitis as it is a broad-spectrum antibiotic and increases the risk of **Clostridioides difficile infection** (CDI).- The 7-day duration is unnecessarily prolonged for treating simple **cystitis** in this patient, contributing to antibiotic selection pressure.

Safe Prescribing UK Medical PG Question 4: A 59-year-old man with type 1 diabetes for 25 years is admitted with acute pancreatitis. His usual insulin regimen is insulin glargine 32 units at bedtime and insulin lispro 8 units with meals. He is kept nil by mouth and started on intravenous fluids. His admission glucose is 16.2 mmol/L. According to best practice for managing insulin in acute illness with nil-by-mouth status, what is the most appropriate insulin management?

• A. Continue insulin glargine at usual dose; omit insulin lispro while nil by mouth (Correct Answer)
• B. Continue insulin glargine; give insulin lispro based on blood glucose readings every 4 hours
• C. Stop all insulin until he is eating and drinking again
• D. Convert to variable-rate intravenous insulin infusion at 0.05 units/kg/hour
• E. Give half the usual total daily insulin dose as basal insulin only

Safe Prescribing Explanation: ***Continue insulin glargine at usual dose; omit insulin lispro while nil by mouth*** - Patients with **Type 1 diabetes** have an absolute insulin deficiency and require continuous **basal insulin** (glargine) to prevent the development of **diabetic ketoacidosis (DKA)**, even when not eating. - **Prandial insulin** (lispro) should be omitted while the patient is **nil by mouth** (NBM) to avoid hypoglycemia, as it is designed to cover carbohydrate intake. *Continue insulin glargine; give insulin lispro based on blood glucose readings every 4 hours* - While **glargine** must continue, scheduled **lispro** is for mealtime coverage; giving it every 4 hours without food intake significantly increases the risk of severe **hypoglycemia**. - High blood glucose readings in an NBM patient should be managed with specific **correction doses** or a variable-rate intravenous insulin infusion if clinically indicated, not routine prandial boluses. *Stop all insulin until he is eating and drinking again* - Stopping all insulin in a Type 1 diabetic is dangerous and will lead to **diabetic ketoacidosis (DKA)** within hours because basal insulin is essential to suppress hepatic glucose production and **ketogenesis**. - Total cessation of insulin is a common clinical error that must be avoided in **Type 1 diabetes** management during acute illness, regardless of nutritional status. *Convert to variable-rate intravenous insulin infusion at 0.05 units/kg/hour* - **Variable-rate intravenous insulin infusion (VRIII)** is typically reserved for metabolically unstable patients (e.g., DKA, severe hyperglycemia, major surgery, critical illness). - For a stable NBM patient with Type 1 diabetes, continuing their **usual subcutaneous basal insulin** is generally preferred as it is simpler and maintains a steady physiological insulin level. *Give half the usual total daily insulin dose as basal insulin only* - Arbitrarily reducing the **basal insulin dose** by half risks insufficient insulin coverage, potentially leading to **hyperglycemia** and metabolic decompensation, especially during acute stress. - The **standard dose of basal insulin** should generally be maintained in Type 1 diabetics to reflect their continuous physiological requirements and prevent DKA.

Safe Prescribing UK Medical PG Question 5: A 68-year-old woman with non-valvular atrial fibrillation (CHA₂DS₂-VASc score 4) is on apixaban 5mg twice daily. She is diagnosed with intermediate-risk myelodysplastic syndrome requiring treatment with azacitidine chemotherapy, which carries significant thrombocytopenia risk (expected platelet nadir 20-50 × 10⁹/L). What is the most appropriate anticoagulation strategy during chemotherapy?

• A. Continue apixaban 5mg twice daily throughout chemotherapy; monitor platelets weekly
• B. Reduce apixaban to 2.5mg twice daily during chemotherapy cycles
• C. Switch to prophylactic-dose LMWH during chemotherapy cycles
• D. Switch to warfarin with target INR 2-3 as it can be more easily reversed
• E. Temporarily stop all anticoagulation during chemotherapy cycles; restart when platelets >50 × 10⁹/L (Correct Answer)

Safe Prescribing Explanation: ***Temporarily stop all anticoagulation during chemotherapy cycles; restart when platelets >50 × 10⁹/L*** - For patients with **thrombocytopenia**, the bleeding risk from therapeutic anticoagulation significantly outweighs the stroke prevention benefit when the **platelet count drops below 50 × 10⁹/L**. - This strategy minimizes the risk of **life-threatening hemorrhage** during the anticipated chemotherapy-induced nadir while allowing for the resumption of protection once platelets recover. *Continue apixaban 5mg twice daily throughout chemotherapy; monitor platelets weekly* - Maintaining full-dose **DOAC therapy** with a platelet count between 20-50 × 10⁹/L carries an unacceptably high risk of **major bleeding**. - Weekly monitoring is insufficient to prevent acute bleeding events when severe **platelet suppression** is actively occurring due to cytotoxic agents. *Reduce apixaban to 2.5mg twice daily during chemotherapy cycles* - Dose reduction of **apixaban** is only indicated for specific criteria (age ≥80, weight ≤60kg, or creatinine ≥133 μmol/L); reducing it for **thrombocytopenia** is not evidence-based. - A reduced dose may still cause significant bleeding at low platelet levels while providing **sub-therapeutic stroke prevention**. *Switch to prophylactic-dose LMWH during chemotherapy cycles* - **Prophylactic-dose LMWH** is inadequate for stroke prevention in a patient with a high **CHA₂DS₂-VASc score** of 4. - In the setting of severe thrombocytopenia, even low-dose anticoagulation is often contraindicated until platelets reach a safer threshold. *Switch to warfarin with target INR 2-3 as it can be more easily reversed* - **Warfarin** is notoriously difficult to manage during chemotherapy due to **drug-nutrient interactions**, nausea, and fluctuating liver function. - The risk of **intracranial hemorrhage** is significantly higher with warfarin compared to DOACs, especially when **platelet counts** are unstable.

Safe Prescribing UK Medical PG Question 6: A 55-year-old woman with type 2 diabetes is on insulin detemir 38 units at 22:00 and metformin 1g twice daily. Her blood glucose readings show: fasting 6-8 mmol/L, pre-lunch 12-15 mmol/L, pre-dinner 10-13 mmol/L, bedtime 8-10 mmol/L. HbA1c is 68 mmol/mol (8.4%). Understanding insulin pharmacodynamics, what is the most appropriate next step in optimizing her insulin regimen?

• A. Split insulin detemir to twice-daily dosing (20 units morning, 20 units evening)
• B. Increase insulin detemir to 44 units at 22:00
• C. Add prandial rapid-acting insulin with main meals (Correct Answer)
• D. Switch from insulin detemir to insulin glargine
• E. Add a GLP-1 receptor agonist

Safe Prescribing Explanation: ***Add prandial rapid-acting insulin with main meals*** - The patient's **fasting glucose** is within target (6-8 mmol/L), indicating the current **basal insulin** dose effectively covers overnight hepatic glucose production. - The significant elevation in **pre-lunch** and **pre-dinner** readings demonstrates inadequate coverage of **post-prandial glucose excursions**, necessitating a **basal-bolus** regimen. *Split insulin detemir to twice-daily dosing (20 units morning, 20 units evening)* - Splitting the dose is typically used when **basal insulin** does not last 24 hours, leading to rising glucose before the next dose, which is not the case here given the stable **fasting readings**. - This adjustment would not provide the rapid peaks required to control **meal-related glucose spikes** seen in this patient. *Increase insulin detemir to 44 units at 22:00* - Increasing the **basal dose** when fasting levels are already at target (6-8 mmol/L) significantly increases the risk of **nocturnal hypoglycemia**. - Basal insulin is designed to manage background levels and is inefficient at controlling high **post-prandial hyperglycemia**. *Switch from insulin detemir to insulin glargine* - Both are **long-acting basal analogues**; switching between them primarily addresses duration of action or injection site reactions rather than **post-prandial control**. - Glargine would still provide a relatively **flat peakless profile**, failing to address the 12-15 mmol/L spikes seen during the day. *Add a GLP-1 receptor agonist* - While **GLP-1 receptor agonists** help with post-prandial glucose and weight, the clinical priority for a patient already on significant insulin with an **HbA1c of 8.4%** is often rapid titration via a **basal-bolus** insulin strategy. - In the context of "optimizing her **insulin regimen**," adding a rapid-acting bolus is the standard pharmacodynamic escalation to match mealtime carbohydrates.

Safe Prescribing UK Medical PG Question 7: A 64-year-old man with atrial fibrillation is on rivaroxaban 20mg once daily. He requires emergency laparotomy for perforated diverticulitis within 2 hours. He took his last dose of rivaroxaban 8 hours ago. His renal function shows eGFR 58 ml/min/1.73m². Pre-operative blood tests show Hb 118 g/L. What is the most appropriate management of his anticoagulation?

• A. Give 4-factor prothrombin complex concentrate 50 units/kg before surgery (Correct Answer)
• B. Proceed to surgery; accept increased bleeding risk as surgery is life-saving
• C. Give fresh frozen plasma 15 ml/kg before surgery
• D. Delay surgery 12 hours to allow rivaroxaban clearance
• E. Give tranexamic acid 1g IV before surgery

Safe Prescribing Explanation: ***Give 4-factor prothrombin complex concentrate 50 units/kg before surgery*** - For life-threatening emergency surgery in patients taking **Direct Oral Anticoagulants (DOACs)** like **rivaroxaban**, reversal is required to prevent catastrophic bleeding; **4-factor PCC** (50 units/kg) is recommended when specific antidotes like andexanet alfa are unavailable. - Given the patient's **eGFR of 58 ml/min** and that the last dose was only **8 hours ago**, significant anticoagulant activity remains as the half-life of rivaroxaban is approximately 5–9 hours. *Proceed to surgery; accept increased bleeding risk as surgery is life-saving* - Proceeding without reversal in a major abdominal surgery like a **laparotomy** carries an unacceptably high risk of **uncontrolled intraoperative hemorrhage**. - Standard of care mandates attempting to restore **hemostasis** before high-risk emergency procedures when the patient is fully anticoagulated. *Give fresh frozen plasma 15 ml/kg before surgery* - **Fresh frozen plasma (FFP)** is ineffective for reversing the effects of **Factor Xa inhibitors** because it lacks the concentration of clotting factors needed to overwhelm the drug effect. - Using FFP would require **large volumes** to provide even minimal pro-coagulant effect, risking fluid overload without providing adequate reversal. *Delay surgery 12 hours to allow rivaroxaban clearance* - **Perforated diverticulitis** is a surgical emergency where delay increases the risk of **fecal peritonitis**, severe **sepsis**, and mortality. - Anticoagulation should be reversed pharmacologically rather than waiting for **metabolic clearance** when the clinical situation is time-critical. *Give tranexamic acid 1g IV before surgery* - **Tranexamic acid** is an **antifibrinolytic** agent that prevents the breakdown of clots; it does not neutralize the **Factor Xa inhibition** caused by rivaroxaban. - While it may be used as an adjunct, it is not a sufficient primary management strategy for **reversing anticoagulant effects** in an emergency.

Safe Prescribing UK Medical PG Question 8: A 46-year-old man with type 1 diabetes for 20 years presents with a 3-month history of unpredictable blood glucose control despite good insulin adherence. He reports that his hypoglycaemic episodes now occur without warning symptoms. Investigations show HbA1c 58 mmol/mol (7.5%) but frequent hypoglycaemia on continuous glucose monitoring. What is the most appropriate modification to his insulin regimen?

• A. Switch to insulin pump therapy with continuous glucose monitoring
• B. Increase overall insulin doses to improve HbA1c
• C. Relax blood glucose targets and accept higher HbA1c to restore hypoglycaemia awareness (Correct Answer)
• D. Add acarbose to slow carbohydrate absorption
• E. Switch from rapid-acting to regular insulin analogues

Safe Prescribing Explanation: ***Relax blood glucose targets and accept higher HbA1c to restore hypoglycaemia awareness*** - This patient presents with **impaired awareness of hypoglycaemia (IAH)**, characterized by the absence of warning symptoms during hypoglycaemic episodes, which is a significant safety concern. - The primary treatment for IAH involves **strict avoidance of hypoglycaemia** for several weeks by intentionally raising blood glucose targets, allowing the **autonomic counter-regulatory responses** to re-establish. *Switch to insulin pump therapy with continuous glucose monitoring* - While **insulin pump therapy (CSII)** and **continuous glucose monitoring (CGM)** are valuable tools for tight glucose management and can help detect hypoglycaemia, they do not directly restore **hypoglycaemia awareness**. - The immediate priority is to modify the patient's physiological response to low glucose, which requires a period free from hypoglycaemia, regardless of the delivery method or monitoring technology. *Increase overall insulin doses to improve HbA1c* - Increasing insulin doses in a patient experiencing **frequent, unwarned hypoglycaemia** would be dangerous, significantly increasing the risk of **severe hypoglycaemic events** and further worsening IAH. - Although the HbA1c is 7.5%, safety takes precedence; aggressively lowering HbA1c in this scenario would compromise patient well-being by inducing more hypoglycaemia. *Add acarbose to slow carbohydrate absorption* - **Acarbose** is an alpha-glucosidase inhibitor primarily used in type 2 diabetes to reduce **postprandial glucose excursions** by delaying carbohydrate absorption in the gut. - It has no role in the management of type 1 diabetes or in restoring **hypoglycaemia awareness**, and its use could complicate the rapid absorption of glucose needed for hypoglycaemia treatment. *Switch from rapid-acting to regular insulin analogues* - **Rapid-acting insulin analogues** are generally preferred in type 1 diabetes as they offer a quicker onset and shorter duration, better mimicking physiological insulin release and providing more flexible dosing. - Switching to **regular insulin** would introduce a slower onset and longer action profile, increasing the risk of **delayed postprandial hypoglycaemia** and making mealtime insulin adjustments more challenging.

Safe Prescribing UK Medical PG Question 9: A 58-year-old woman with atrial fibrillation is on edoxaban 60mg once daily. She develops acute bacterial endocarditis affecting the mitral valve and requires valve replacement surgery in 48 hours. Current renal function shows eGFR 65 ml/min/1.73m². What is the most appropriate approach to managing her anticoagulation perioperatively?

• A. Continue edoxaban until 24 hours before surgery, then restart 6 hours post-operatively
• B. Stop edoxaban 48 hours before surgery, bridge with LMWH, restart edoxaban post-operatively
• C. Stop edoxaban now, give PCC for reversal, start warfarin post-operatively with LMWH bridge (Correct Answer)
• D. Stop edoxaban now, start intravenous heparin infusion, restart edoxaban post-operatively
• E. Stop edoxaban now, no bridging required, restart edoxaban 24-48 hours post-operatively

Safe Prescribing Explanation: ***Stop edoxaban now, give PCC for reversal, start warfarin post-operatively with LMWH bridge*** - This patient requires a **mechanical mitral valve replacement**, which is a **contraindication** for **Direct Oral Anticoagulants (DOACs)** like edoxaban due to the high risk of valve thrombosis and systemic embolism. - For urgent surgery (48 hours) with a DOAC, immediate cessation is required. **Prothrombin Complex Concentrate (PCC)** can be considered for rapid reversal, and post-operatively, the patient must be transitioned to **warfarin** (a Vitamin K antagonist) with a **low molecular weight heparin (LMWH) bridge** until the INR is therapeutic. *Continue edoxaban until 24 hours before surgery, then restart 6 hours post-operatively* - Continuing edoxaban until 24 hours before major cardiac surgery carries a significant **bleeding risk**, as the drug's anticoagulant effect may still be present during the procedure. - **Restarting edoxaban** post-operatively is inappropriate because DOACs are not recommended for patients with **mechanical heart valves** due to increased thrombotic events. *Stop edoxaban 48 hours before surgery, bridge with LMWH, restart edoxaban post-operatively* - While stopping edoxaban 48 hours before surgery is appropriate for some procedures, **restarting edoxaban** is incorrect for a patient with a new **mechanical heart valve**. - **DOACs** have shown **inferiority to warfarin** and increased adverse events in clinical trials (e.g., RE-ALIGN trial with dabigatran) for mechanical heart valve prophylaxis. *Stop edoxaban now, start intravenous heparin infusion, restart edoxaban post-operatively* - While **intravenous heparin** could serve as a perioperative bridge, the plan to **restart edoxaban** post-operatively is fundamentally flawed. - Patients with **mechanical mitral valves** require **warfarin** for long-term anticoagulation, targeting a specific INR range (e.g., 2.5-3.5) to prevent thrombosis. *Stop edoxaban now, no bridging required, restart edoxaban 24-48 hours post-operatively* - Immediately stopping edoxaban is correct, but **no bridging** pre- or post-operatively (until warfarin is therapeutic) for a mechanical valve places the patient at a very high risk of **valve thrombosis** and thromboembolic events. - **Restarting edoxaban** is definitively incorrect as it is contraindicated for **mechanical heart valves**.

Safe Prescribing UK Medical PG Question 10: A 52-year-old woman with type 2 diabetes is established on insulin glargine 42 units at bedtime and metformin 1g twice daily. She is about to commence treatment for latent tuberculosis with rifampicin 600mg daily for 3 months. What is the most important consideration regarding her diabetes management?

• A. Rifampicin has no effect on insulin requirements
• B. Rifampicin may increase insulin requirements significantly due to enzyme induction (Correct Answer)
• C. Rifampicin may decrease insulin requirements due to improved insulin sensitivity
• D. Metformin dose should be reduced due to interaction with rifampicin
• E. Insulin glargine should be switched to NPH insulin due to rifampicin interaction

Safe Prescribing Explanation: ***Rifampicin may increase insulin requirements significantly due to enzyme induction***- Rifampicin is a potent **CYP450 enzyme inducer**, accelerating the metabolism of endogenous hormones like cortisol, leading to increased **insulin resistance**.- This increased resistance necessitates a **higher dose of insulin** to maintain glycemic control, often requiring careful monitoring and dose adjustments. *Rifampicin has no effect on insulin requirements*- This is incorrect as rifampicin significantly impacts **glucose metabolism** by inducing hepatic enzymes, which alters the clearance of substances affecting blood glucose.- Due to its **enzyme-inducing properties**, rifampicin frequently leads to hyperglycemia and increased insulin requirements in diabetic patients. *Rifampicin may decrease insulin requirements due to improved insulin sensitivity*- Rifampicin does not improve **insulin sensitivity**; rather, its effects on drug metabolism typically lead to increased insulin resistance.- A decrease in insulin requirements is usually associated with conditions like **renal impairment** or drugs that enhance insulin sensitivity, which is not the case here. *Metformin dose should be reduced due to interaction with rifampicin*- Rifampicin can induce transporters involved in **metformin uptake and elimination**, potentially *decreasing* metformin's plasma concentration and efficacy, not increasing toxicity.- Therefore, a **reduction in metformin dose** is not indicated; the primary concern remains the increased insulin resistance and need for more insulin. *Insulin glargine should be switched to NPH insulin due to rifampicin interaction*- There is no clinical or pharmacological basis to switch from **insulin glargine** (a long-acting basal insulin) to NPH insulin due to rifampicin co-administration.- The type of basal insulin is less relevant than the overall **insulin dosage**, which needs to be adjusted upwards to counteract rifampicin-induced insulin resistance.

Safe Prescribing Flashcard 1 of 10

Question: Lithium has a very _____ therapeutic range, toxicity occurs when levels are >1.5 mmol/L

Answer: narrow

Safe Prescribing Flashcard 2 of 10

Question: Management of patients who have taken a _____ paracetamol overdose involves NAC treatment regardless

Answer: staggered

Safe Prescribing Flashcard 3 of 10

Question: _____ drugs may be used with senior support AND extreme caution in patients with TCA toxicity if IV hypertonic sodium bicarbonate fails

Answer: Anti-arrhythmic

Safe Prescribing Flashcard 4 of 10

Question: Recreational drugs such as _____ and cocaine may cause serotonin syndrome

Answer: Ecstasy (MDMA)

Safe Prescribing Flashcard 5 of 10

Question: When do you calculate adjusted calcium? _____

Answer: hypo or hyperalbuminaemia

Safe Prescribing Flashcard 6 of 10

Question: What is an example of a 5-HT3 antagonist (blocks seratonin)?

Answer: • Ondanestron

Safe Prescribing Flashcard 7 of 10

Question: What drugs end with 'flozin'

Answer: SGLT-2 inhibitors

Safe Prescribing Flashcard 8 of 10

Question: What electrolyte disturbance can loop diuretics cause?

Answer: Hyponatraemia

Safe Prescribing Flashcard 9 of 10

Question: What medication can cause neutrophilia?

Answer: • Prednisolone

Safe Prescribing Flashcard 10 of 10

Question: What has occured if a patient on Mesalazine is now experiencing epigatrium pain that radiated through to his back?

Answer: • Acute pacreatitis