Medicines matter: the expanding role of the perioperative pharmacist

Case history

A 78-year-old man is diagnosed with rectal cancer. His medical history includes prostate cancer treated with hormone inhibitor therapy and long-term steroids, atrial fibrillation (AF) managed with lifelong anticoagulation, type-1 diabetes mellitus, hypertension and heart failure. The surgical multidisciplinary team (MDT) established a treatment plan consisting of neo-adjuvant chemotherapy followed by elective robotic high anterior resection.

The surgery is completed without complications, and the patient is stepped down to the ward where, on the first postoperative evening, he develops persistent hyperglycaemia and tachycardia. He is found to be hyponatraemic and ketotic and is initially managed with intravenous fluids, variable rate insulin infusion and a beta-blocker.

The patient then suffers an episode of acute desaturation associated with AF with rapid ventricular response. Clinical examination reveals fluid overload with evidence of pulmonary oedema. Cautious diuretics and intravenous stress dose steroids are commenced with regular electrolyte monitoring. A raised troponin without ischaemic electrocardiogram (ECG) changes suggests myocardial injury secondary to rapid AF and acute decompensated heart failure.

With supportive treatment, the patient went on to make a full recovery. A departmental morbidity review would go on to identify the following failures in care:

• Inadequate perioperative steroid replacement therapy.

• Failure to restart the patient’s basal insulin post-operatively coupled with inappropriate early discontinuation of variable rate insulin infusion when still nil-by-mouth.

• Failure to restart preadmission beta-blocker.

• Excessive intravenous fluid administration contributes to electrolyte derangements, fluid overload and respiratory distress.

Clinical question

What role should perioperative pharmacists play in preventing medication errors during the perioperative period?

Case discussion

Medication errors are a leading cause of avoidable harm in healthcare systems across the world [1]. This narrative vignette opens a discussion around the important role of the perioperative pharmacists in reducing iatrogenic harm and how such services will add value to the care of patients.

Patients with multiple morbidities, requiring major surgery, are commonplace in our daily practice. The increasing complexity of the surgical population and the potential risk of iatrogenic harm make perioperative medication management a critical feature of high-quality care for all our patients.

Pharmacists undertaking medicines reconciliation (MedsRec) play a key role in verifying a patient’s current medication and identifying and rectifying any discrepancies. The National Institute for Health and Care Excellence (NICE) recommends that this activity takes place within 24 hours of admission in an acute setting to reduce medicines-related patient safety incidents [2]. Over recent years, MedsRec has become an indispensable tool in the UK healthcare system and is now embedded in all secondary-care activities.

Despite these advances, medicines management in the perioperative period remains an area susceptible to medication-related patient safety concerns. Studies have identified challenges in the consistent application of MedsRec in elective perioperative settings. Thompson [3] and Brunswicker [4] identified that patients undergoing elective surgery were often admitted without adequate MedsRec or thorough drug chart documentation. A recent study at a large UK tertiary care hospital by Potter et al. [5] confirmed similar findings, revealing a high frequency of preoperative assessment MedsRec errors and numerous unexplained prescribing omissions. The risk of patient harm was deemed significant.

It is common practice within perioperative care for MedsRec to take place after admission. However, for an elective surgical patient the surgical journey begins long before that. The preoperative period is increasingly seen as a time available for detailed care planning, often involving an multidisciplinary team (MDT) approach and focused on optimising the patient for surgery. Nutrition, lifestyle modifications, psychological support and physical conditioning are all well-established components of prehabilitation programmes. However, while medicines optimisation is known to improve perioperative outcomes [6], its importance may be overlooked. Locally developed guidelines often lack the required consistency and standardisation. In support of improved medicines management in the perioperative period, the UK Clinical Pharmacy Association has produced a valuable perioperative medicines handbook [7], providing guidance for the therapeutic management of clinical conditions, for instance the perioperative augmentation of steroids or the management of diabetes mellitus. However, despite this, its use is not universally embedded into practice and the absence of a cohesive national strategy for perioperative medicines management highlights a weakness in the current patient preoperative assessment process [8].

A move to a new standard of care might therefore be considered, in which pharmacist support moves to a proactive involvement with surgical patients and their medicines, rather than reactive, after a patient has been admitted and often has already undergone surgery. This model seeks to bring forwards the oversight of medicines management into the presurgery domain. Here, the perioperative pharmacist working in conjunction with clinicians can perform both MedsRec and medicines optimisation simultaneously to generate a personalised medicines management plan in preparation for surgery. Looking several steps ahead, such a plan might lay the groundwork for addressing a wide range of pharmaceutical care issues, e.g. drug interactions, therapeutic drug monitoring, dose adjustments, necessary formulation changes and surgical factors affecting drug pharmacokinetics.

Maintaining continuity of care, inpatient pharmacists would maintain an oversight of the initial medication plan. The plan can be adjusted in response to any unforeseen circumstances including major complications, which occur in 10–20% of patients undergoing major surgeries [9]. Commonly occurring complications are likely to have significant implications for medicines management. For example, postoperative bleeding, occurring in up to 12% of cases [10], will impact decision making for anticoagulation and deep venous thrombosis prevention. Perioperative hypotension is common, affecting 5–50% of patients undergoing major surgery [11, 12] and is likely to influence prescribing, particularly in those at greatest risk of cardiovascular morbidity. Perioperative acute kidney injury (AKI) has an incidence of between 1% and 13% [13, 14, 15], while postoperative ileus occurs in 5–30% of those undergoing abdominal surgery [16, 17], affecting available routes of administration, and altering absorption, bioavailability and clearance of drugs. These influences on drug pharmacokinetics often necessitate formulation modifications and dose adjustments [18, 19].

The perioperative pharmacist has a central role in embedding and maintaining strong medicines governance. For example, their role in antibiotic stewardship is important in reducing antimicrobial resistance, iatrogenic harm and the inevitable costs of inappropriate antibiotic therapy [20, 21].

As the surgical population ages, there will be a growing requirement for the involvement of perioperative pharmacist services. By 2030 it is estimated that more than 1.4 million patients aged over 75 years will undergo surgery each year [22]. Polypharmacy for this patient cohort can be significant, ranging between 26% and 65% [23] and will have meaningful implications on their perioperative medicines management.

The NHS Long Term Workforce Plan has emphasised the need to train, retain and transform its workforce, as over 6 million patients await the start of their surgical journey [24, 25]. Clinical pharmacists bring a unique skill set to this challenge, combining at least 5 years of preclinical and clinical training in pharmaceutical sciences and therapeutics. Despite their expertise, pharmacist involvement in perioperative pathways remains inconsistent across UK centres. This represents a significant opportunity to safely extend the scope of practice across a range of professional groups. The role of the clinical pharmacist has evolved considerably in recent years, with many now acting as independent prescribers, chairing unlicensed medicines and therapeutics committees, and leading on clinical guideline development and education within both medical and surgical specialties. These developments reflect a broader move towards interdisciplinary task sharing, in which pharmacists complement and support the clinical and governance responsibilities of prescribers, nurses and other members of the MDT. However, this progress must be carefully balanced to avoid a substitution mindset. Medicines safety is a collective responsibility, and the integration of pharmacists into perioperative care should be viewed as a means to enhance collaboration and improve outcomes, not as a replacement for the roles and vigilance of others within the team. It is important that pharmacists are not seen as replacements for existing members of the MDT.

Conclusion

The introduction of the MedsRec framework to the NHS in 2007 marked a pivotal shift in medicines management. This standardised approach transformed acute care by reducing medication errors during transitions of care, delivering measurable cost savings and enhancing patient outcomes [26, 27, 28]. From 2026, Pharmacy graduates will enter the workforce not only with a strong foundation in clinical and pharmaceutical sciences, but also as independent prescribers. These enhanced capabilities uniquely position the modern perioperative pharmacist to play a vital role in surgical care: supporting clinical decision making, preventing medication-related harm, and facilitating a safer, more seamless, perioperative journey. Proactive integration of pharmacists into surgical teams can act as a catalyst for improving patient safety, operational efficiency and medicines governance. As surgical demand increases and patient complexity rises, future models of perioperative care must recognise pharmacists not as optional contributors, but as core providers of safe, cost-effective and evidence-based care. Medicines matter, and the real question is no longer whether we can afford to involve perioperative pharmacists, but whether we can afford not to.

Declarations and conflicts of interest