Navigating medicines management in the peri-procedural period

Introduction

Australians make 440 million visits to their pharmacist each year,¹ with community pharmacists frequently consulted by patients preparing for diagnostic or minor surgical procedures. These encounters often occur when instructions are unclear, leaving patients unsure which medicines to stop, when to stop them, and how to safely resume therapy. Temporary medicine changes can be particularly confusing for patients using dose administration aids (DAAs), increasing the risk of dosing errors or procedural delays. 

Pharmacists are well placed to address this gap. As accessible healthcare professionals with medicines expertise, pharmacists can identify medicines that increase peri-procedural risk, clarify instructions, and support safe temporary changes.

This article provides a practical, evidence-based overview of medicines commonly withheld prior to procedures, counselling strategies to minimise confusion, guidance for managing DAAs, and pharmacy-based interventions to support patient safety.

Medicines commonly withheld prior to procedures

Patients preparing for diagnostic investigations or minor surgical procedures are often advised to temporarily withhold selected medicines to reduce peri-procedural risk. The decision to continue or withhold a medicine involves balancing potential risks of the procedure (such as bleeding, infection, haemodynamic instability, renal impairment, metabolic disturbance or interactions with medicines used in the peri-procedural period)
against the risk of disease exacerbation or withdrawal effects. Pharmacists play
a critical role in identifying medicines that may require review, clarifying prescriber instructions and supporting safe temporary modification of therapy.²

Anticoagulants and antiplatelet agents are among the most frequently managed medicines in the peri-procedural setting. Oral anticoagulants, including warfarin and direct oral anticoagulants, increase bleeding risk during procedures such as colonoscopy, dermatological excisions, and some dental or ophthalmic surgeries.³ Antiplatelet therapy presents a more nuanced risk-benefit balance. For many minor procedures, including cataract surgery and simple dental or dermatological procedures, aspirin may be safely continued, while procedures with a higher bleeding risk may necessitate temporary cessation.⁴

The decision to withhold antithrombotic therapy is highly individualised and should always be clinician-directed. Pharmacists should avoid advising cessation independently but can support patient safety by reinforcing clear stop and restart dates, and emphasising the importance of timely recommencement to minimise thromboembolic risk.^3,4

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly withheld prior to procedures due to their reversible inhibition of platelet aggregation and their potential to impair renal perfusion, particularly in the context of peri-procedural dehydration or exposure to contrast media.^2,5 Platelet function typically normalises within several days of NSAID discontinuation, although this varies by agent.⁵ From a pharmacy perspective, the most significant risk arises from unrecognised over-the-counter NSAID use. Pharmacists should proactively enquire about non-prescription analgesics and recommend suitable alternatives, such as paracetamol, where appropriate.^2,5

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) remain an area of clinical debate. Continuation has been associated with an increased risk of intraoperative hypotension, while cessation may increase the likelihood of postoperative hypertension.^9-11 Evidence supports an individualised approach, taking into account the indication for therapy, baseline blood pressure, and the nature of the procedure and anaesthesia.^9,10 In practice, many clinicians elect to withhold these agents on the morning of surgery when hypotension risk is high and resume therapy promptly post-procedure. Failure to recommence ACEIs or ARBs within 24–48 hours postoperatively has been associated with increased short-term mortality.^9–11 Pharmacists should reinforce clinicians’ pre-procedure instructions, provide rationale and highlight the importance of timely recommencement.

Complementary and herbal products require review in the peri-procedural period, as evidence indicates their use remains highly prevalent among surgical patients, yet disclosure to healthcare professionals is often incomplete.^1,12 Herbal medicines may exert clinically significant pharmacodynamic and pharmacokinetic effects that increase peri-procedural risk, including impaired platelet aggregation (e.g. garlic, ginkgo biloba, ginseng), increased sedative effect (e.g. kava, valerian) and altered metabolism of anaesthetic or perioperative medicines through cytochrome P450 enzyme induction (e.g. St John’s wort).^2,13 Risk assessment is further complicated by variability in product composition, dosing and bioactive constituents, meaning effects are not always predictable or dose dependent.¹¹ As a result, many contemporary guidelines recommend discontinuation of non-essential herbal medicines at least 1–2 weeks prior to procedures, depending on the agent and procedural risk.^2,13

Diabetes medicines and peri-procedural blood glucose management

Medicines used to manage diabetes often require review in the peri-procedural period. Temporary changes may be needed to reduce medicine-related risk during fasting and recovery, and pharmacists play an important role in supporting patient understanding and continuity of care.

Sodium-glucose co-transporter-2 (SGLT2) inhibitors warrant specific attention in the peri-procedural period due to the risk of diabetic ketoacidosis (DKA), which may occur with near-normal or only mildly elevated blood glucose levels (euglycaemic DKA). The risk is increased during periods of fasting, reduced carbohydrate intake (including bowel preparation), dehydration, acute illness and surgical stress. Importantly, normoglycaemia does not exclude DKA, and blood ketone testing should be considered where clinical suspicion exists. Clinical guidelines advise that SGLT2 inhibitors should be withheld for at least 3 days prior to procedures requiring fasting or bowel preparation (and 4 days for ertugliflozin).⁶ 

Physiological stress related to illness, fasting, anxiety and surgical intervention activates counter-regulatory hormones such as cortisol and catecholamines, leading to increased hepatic glucose output and reduced insulin sensitivity.⁷ When combined with altered oral intake and temporary medicines changes, this stress response can result in significant glycaemic variability, even in patients with previously stable diabetes.^2,3

Extremes of blood glucose pose specific risks in the peri-procedural setting. Hyperglycaemia is associated with dehydration, impaired immune function and an increased risk of postoperative infection, while hypoglycaemia may result in neuroglycopenic symptoms, cardiovascular instability or loss of consciousness – particularly in the context of fasting or reduced caloric intake.⁸ For most adults, general peri-procedural targets include fasting blood glucose levels of approximately 4–8 mmol/L and random levels below 10 mmol/L, although individual targets should be tailored based on comorbidities, frailty and procedural complexity.⁸ Pharmacists play an important role in reinforcing blood glucose monitoring plans, supporting sick-day management principles, therapy modification during temporary medicine cessation, and identifying when abnormal readings require medical review. Clear counselling on when and how to safely recommence withheld medicines once normal oral intake has resumed is essential to minimise metabolic complications and support safe transitions of care.^2,6

Managing temporary cessation in DAAs

Patients who use DAAs are at increased risk of medication error when medicines are changed, particularly when temporarily withheld in the peri-procedural period.¹⁴ These patients often rely on the pack as their primary prompt for medicine administration and may not be familiar with individual medicines or their indications. Temporary cessation without appropriate pharmacist intervention can lead to duplication or unintended continuation of withheld medicines. Pharmacists therefore play a critical role in coordinating safe, structured modifications in response to procedural instructions.

Best practice involves pharmacist-led removal of specific medicines from affected doses, rather than advising patients to self-remove tablets, which increases the risk of error and pack disruption. Clear documentation should accompany any changes, including written instructions outlining which medicines have been withheld, the duration of cessation, and the planned date of recommencement, where possible. If feasible, pharmacists should provide a simple, procedure-specific DAA and schedule follow-up to ensure medicines are safely reintroduced post-procedure.

Liaison with prescribers may be required if instructions are unclear or if the patient’s clinical status changes. Through proactive management of DAAs, pharmacists can significantly reduce confusion, support continuity of care, and minimise preventable medicine-related harm and delays in the peri-procedural setting.

Knowledge to practice

Community pharmacists can proactively review medicines prior to procedures, identify medicines that may require temporary cessation, clarify clinician-directed stop-restart instructions, and manage changes to DAAs.

By reinforcing written advice, reviewing over-the-counter and complementary medicine use, and supporting blood glucose monitoring during periods of fasting or medicine withholding, pharmacists minimise confusion and prevent medicine-related harm. Pharmacists can also support peri-procedural care by encouraging patients to bring all medicines for review and by providing an accurate medicines list to assist communication across care settings.

Conclusion

Pharmacists play a critical role in supporting patients preparing for common procedures through proactive medicines review, clear counselling and practical support for temporary medicine changes. This role is particularly important for patients using DAAs, where structured pack modification and follow-up can reduce medication errors and delays to care. As peri-procedural medicines management becomes increasingly complex, pharmacist-led interventions are essential to safe, coordinated and patient-centred care.