Collaborating with Prescribing Physicians on Medication Questions
Level 3, Clinical application
In brief
Nutrition and lifestyle change often affects medicines: glucose lowering drugs may need reducing as diet improves, antihypertensives as weight falls, warfarin with changes in vitamin K, levothyroxine with changes in routine, lithium with changes in salt and fluid, and SGLT2 inhibitors with very low carbohydrate diets. Practitioners who anticipate these effects, communicate clearly and respect the prescriber’s role keep patients safe and support deprescribing where appropriate.
Integrated care often succeeds so well that it creates a new challenge. A patient whose diet and weight improve may no longer need the same dose of glucose lowering medicine, and may become hypoglycaemic if nothing changes. A patient whose blood pressure falls may become dizzy on their usual antihypertensives. A patient starting a new diet may unknowingly alter the effect of warfarin. Anticipating these effects and working with prescribers to manage them is one of the most important safety responsibilities in integrated practice.
Situations that need prescriber input
| Situation | Risk | What to communicate |
|---|---|---|
| Reducing carbohydrate or losing weight while taking insulin or sulphonylureas | Hypoglycaemia | Dietary plan, glucose readings, any symptoms of low glucose |
| Very low carbohydrate or ketogenic diet while taking SGLT2 inhibitors | Ketoacidosis | Diet plan before it starts |
| Weight loss or sodium reduction while taking antihypertensives | Low blood pressure, dizziness, falls | Home blood pressure readings, symptoms |
| Diuretics with reduced intake or fasting | Dehydration, electrolyte disturbance | Planned fasts, intake changes |
| Changes in green vegetable intake or vitamin K supplements while taking warfarin | Unstable INR | Dietary changes; aim for consistency |
| Changes in coffee, calcium, iron, soy or fibre around levothyroxine | Altered absorption | New routines, supplements |
| Changes in salt, fluid or diuretic use while taking lithium | Lithium toxicity | Any dietary sodium or fluid changes, illness |
| Potassium supplements or salt substitutes with ACE inhibitors, angiotensin receptor blockers or potassium sparing diuretics | Hyperkalaemia | Products used |
| Supplements that interact with medicines | Various | Product names, ingredients, doses |
| Resolved symptoms on long term medicines, such as acid suppressants | Opportunity to deprescribe | Symptom history and current status |
| Religious fasting while taking diabetes or other medicines | Hypoglycaemia, dehydration | Fasting plans in advance |
Principles of collaboration
Anticipate
Before starting a plan likely to affect medicines, inform the prescriber. It is far safer to plan a dose reduction than to respond to a hypoglycaemic episode.
Monitor
Ask patients to monitor relevant measures, such as home glucose or blood pressure readings, and to report symptoms such as shakiness or dizziness.
Communicate clearly
Use a structured format, such as situation, background, assessment and recommendation, and include specific data. Vague messages such as “your patient is eating better” are less useful than “her fasting glucose readings have fallen from 8 to 5 mmol/L over 3 weeks and she has had 2 episodes of shakiness before lunch”.
Respect roles
Decisions about medicines belong to the prescriber and the patient. The practitioner’s role is to provide information and observations, not to instruct.
Support the patient
Patients sometimes want to stop medicines as soon as they feel better. Explaining why changes should be planned with the prescriber, and helping them prepare for that conversation, supports both safety and autonomy.
Deprescribing
Deprescribing, the planned reduction or stopping of medicines that are no longer needed or whose risks outweigh their benefits, is increasingly recognised as part of good care, particularly in older adults taking many medicines. Evidence based guidance exists for deprescribing some drug classes, such as proton pump inhibitors, benzodiazepines and some diabetes medicines in older adults, and tools such as the STOPP and START criteria help identify potentially inappropriate prescribing. Lifestyle improvements can create opportunities for deprescribing, but the decision and process remain with the prescriber.
Communicating with patients about medicines
| Patient says | Helpful response |
|---|---|
| “I feel better; can I stop my tablets?” | “That’s great progress. Let’s share your readings with your doctor, who can decide whether and how to adjust them safely.” |
| “I don’t like taking medicines.” | “Many people feel that way. Your medicine is doing an important job right now. As your health improves, your doctor may be able to review it.” |
| “My doctor won’t listen.” | “Let’s write down your readings and questions so the conversation is as clear as possible. I can also send a summary.” |
A template message to a prescriber
Situation: I am supporting Mr B with nutrition for type 2 diabetes. Background: he takes metformin and gliclazide. Over 4 weeks he has reduced refined carbohydrate substantially and lost 3 kg. Assessment: his fasting glucose readings have fallen from around 9 to 5 to 6 mmol/L, and he has had 3 episodes of shakiness and sweating before lunch, relieved by eating. Recommendation: could you review his gliclazide dose? I have advised him to carry glucose tablets and to contact you if symptoms recur.
Shared care plans
For patients with complex needs, a shared care plan, a single document listing goals, medicines, lifestyle interventions, monitoring and responsibilities, helps everyone work from the same page. It should be updated after each significant change and shared with the patient.
An illustrative case
A 64 year old man with type 2 diabetes treated with insulin and metformin, and hypertension treated with 2 medicines, begins a structured weight management programme. Before he starts, his practitioner writes to his doctor with the plan. His doctor reduces his insulin dose preemptively and asks for weekly readings. Over 3 months he loses 11 kg. His insulin is gradually reduced and then stopped, and one of his blood pressure medicines is reduced after home readings show low values and he reports dizziness on standing. There are no hypoglycaemic episodes and no falls. The outcome depended as much on the collaboration as on the programme.
Partnership for safety
Successful lifestyle change can transform a patient’s need for medicines. Practitioners who anticipate that, monitor carefully and communicate clearly with prescribers make sure the transformation is safe, and help patients reach the point where fewer medicines are needed.
Questions about collaborating with prescribers
Can diet changes affect medication needs?
Who decides on medication changes?
What is deprescribing?
References
- O’Mahony D, Cherubini A, Guiteras AR, et al. STOPP/START criteria for potentially inappropriate prescribing in older people: version 3. European Geriatric Medicine. 2023;14(4).
- Farrell B, Pottie K, Thompson W, et al. Deprescribing proton pump inhibitors: evidence based clinical practice guideline. Canadian Family Physician. 2017;63(5).
- Evert AB, Dennison M, Gardner CD, et al. Nutrition therapy for adults with diabetes or prediabetes: a consensus report. Diabetes Care. 2019;42(5).
- Hassanein M, Afandi B, Yakoob Ahmedani M, et al. Diabetes and Ramadan: practical guidelines 2021. Diabetes Research and Clinical Practice. 2022;185.
- Lean MEJ, Leslie WS, Barnes AC, et al. Primary care led weight management for remission of type 2 diabetes (DiRECT): an open label, cluster randomised trial. The Lancet. 2018;391(10120).
Continue your learning
Working with prescribers effectively
Collaborating safely with prescribing doctors is a core skill in IIFM’s 6 month Functional Medicine and Clinical Nutrition program, practised through case discussion across every module.
This article is for the education of healthcare professionals. It is not a substitute for individual medical advice, diagnosis or treatment, and does not change any practitioner’s scope of practice. Regulation and guidelines differ between countries.