I have heard several people talk about how they self-medicate or adjust their medication when they do something that they’re not supposed to. It worries me, so I reached out to Anand Sheth, who’s a pharmacist, and asked him if he could write an article about it for HeenaModi.com.
Here it is! I can’t wait to hear your thoughts about it.
From a pharmacist’s perspective, one of the most common and dangerous problems in healthcare is not simply that patients stop medicines, but that they do so silently. In practice, patients often do not tell their pharmacist, GP, specialist, nurse prescriber, or other healthcare professional that they have reduced a dose, skipped tablets, restarted an old medicine, or stopped treatment completely.
This is rarely because they are “difficult” patients. More often, it reflects a mix of side effects, practical barriers, cost, fear, misunderstanding, and a genuine belief that they are doing the sensible thing.
Why do patients stop medication without telling a healthcare professional?
A useful way to understand this is through the concept of medication adherence. Vrijens et al. describe adherence as having three components:
- Initiation (starting the medicine)
- Implementation (taking it as prescribed, day to day)
- Discontinuation/persistence (how long a person continues treatment before stopping)
In other words, problems can arise before the first dose, during regular use, or when treatment is stopped early.
The National Institute for Health and Care Excellence (NICE), the UK body that produces clinical guidelines, also distinguishes between:
- Intentional non-adherence (choosing not to follow treatment)
- Unintentional non-adherence (wanting to take it but being unable to do so reliably)
These can be grouped into key types:
- Primary non-adherence (non-initiation): the patient never starts the medicine
- Poor implementation: inconsistent use, missed doses, altered timing or dose
- Non-persistence: stopping earlier than intended
- Intentional non-adherence: conscious decision not to follow treatment
- Unintentional non-adherence: barriers prevent correct use
In practice, these categories overlap. The following reasons show how this plays out in real life.
1. Side effects and fear of side effects
The most obvious reason patients stop treatment is that the medicine makes them feel worse before it makes them feel better. Nausea, dizziness, fatigue, sexual dysfunction, weight gain, constipation, diarrhoea, sleep disturbance, and dry mouth are all common reasons for deciding that a medicine is “not for them.”
Sometimes the issue is not an actual side effect but the fear of one—often shaped by patient information leaflets, online searches, or hearing about someone else’s experience. The Necessity–Concerns Framework shows that adherence depends on how much patients feel they need the medicine versus how worried they are about harm (Horne et al.).
From a pharmacist’s perspective, this matters because many side effects can be managed. The dose may be adjusted, timing changed, formulation switched, or the medicine replaced—but patients often stop before that conversation happens.
2. They feel better, so the medicine seems unnecessary
Once symptoms improve, it is natural to assume the medicine has “done its job.” This is common in long-term conditions such as hypertension, atrial fibrillation, epilepsy, or high cholesterol, where the benefit is preventive rather than immediately noticeable. The WHO highlights that patients often stop treatment when they feel better, even when the risk
remains.
The key issue: many medicines do not cure the condition—they control it. Feeling well does not always mean the disease has gone.
3. Intentional non-adherence: a deliberate choice
Some patients actively adjust treatment—taking medicines on alternate days, splitting tablets, or only using them when symptoms flare.
This may reflect previous experiences, concerns about dependence, stigma, or a desire for control. Lehane and McCarthy show that intentional and unintentional non-adherence are different behaviours and should be approached differently.
This is especially important in mental health, where abrupt stopping can lead to withdrawal or relapse.
4. Unintentional non-adherence: life gets in the way
Not all non-adherence is a choice. Many patients struggle with practical issues—forgetting doses, misunderstanding instructions, running out of medication, or managing complex routines.
Factors such as poor eyesight, reduced dexterity, language barriers, shift work, and travel all contribute. The more complex the regimen, the harder it is to follow consistently (Kardas et al.).
From a pharmacist’s perspective, this highlights that knowledge alone is not enough—capacity matters.
5. Primary non-adherence: never starting at all
Some patients never begin treatment. Prescriptions go uncollected or medicines are declined due to concerns about side effects, cost, or uncertainty.
Lee et al. emphasise that this is distinct from later adherence problems. Clinicians may assume treatment failure when, in reality, the medicine was never taken.
6. Cost, access, and system barriers
Cost and access remain major factors. Briesacher et al. found strong links between financial burden and reduced adherence.
Even in publicly funded systems, issues such as delayed follow-up, confusing repeat prescription processes, and poor communication during transitions of care can lead to missed doses or unintended stopping.
7. Poor communication or explanation
Sometimes medicines are stopped because they were never properly explained.
NICE emphasises shared decision-making and informed choice. Without this, patients are left to interpret risks and benefits themselves—often without the full picture.
Stigma, denial, and treatment fatigue
Some conditions carry stigma, and long-term treatment can be exhausting. “Treatment fatigue” is common, especially in people managing multiple conditions. Patients may stop medication without telling anyone because they feel judged, embarrassed, or overwhelmed.
Non-adherence is not simply a patient failing—it reflects complex interacting factors.
What actually happens when patients stop medication?
Understanding why patients stop medicines is only part of the story. The next question is:
What happens when they do?
Why patients should not just stop taking medication unless consulted by a healthcare professional
Medicines are chosen, dosed, monitored, and stopped within a clinical context. Healthcare professionals consider the diagnosis, organ function, drug interactions, previous response, and whether a medicine needs to be tapered, switched, or continued.
Removing that context can lead to harm.
1. The condition can return or worsen
Stopping treatment allows the underlying condition to re-emerge.
This may result in mild symptoms, but in some cases it can lead to serious outcomes such as stroke, seizure, relapse of disease, transplant rejection, or death. Good adherence to medication is consistently associated with lower mortality and reduced hospitalisation (Walsh et al.).
2. Withdrawal and rebound effects
Some medicines need to be reduced gradually rather than stopped suddenly, because the body adapts to their presence over time.
For example, antidepressants can cause discontinuation syndrome in around 20% of patients if stopped abruptly. This refers to a group of symptoms that occur when the body reacts to the sudden absence of the medicine. These may include dizziness, insomnia, nausea, and unusual sensations often described as “electric shock” feelings.
Beta-blockers can cause rebound tachycardia, meaning the heart rate increases above normal after stopping the medicine. In some cases, this can progress to more serious complications such as myocardial infarction (a heart attack), particularly if the medicine was controlling underlying cardiovascular disease (Frishman).
Corticosteroids such as prednisolone can lead to adrenal insufficiency if withdrawn too quickly. This occurs because the body’s natural steroid production has been suppressed, and it cannot immediately compensate. As a result, patients may experience fatigue, low blood pressure, and an impaired response to physical stress.
Importantly, these effects are not simply the original illness returning. They are physiological responses, meaning they occur because the body has adapted to the medicine and is reacting to its sudden removal.
3. Loss of invisible protection
Some medicines reduce long-term risk without producing noticeable day-to-day effects. Anticoagulants used in atrial fibrillation are a key example. These medicines reduce the risk of stroke by preventing blood clots from forming. However, their protective effect declines quickly when doses are missed, and non-persistence is associated with a significantly increased risk of stroke (Holthuis et al.).
Feeling “fine” does not mean the medicine is unnecessary—it may be providing ongoing protection against serious complications.
4. Risk of medical emergencies
In some cases, stopping medication can trigger acute and potentially life-threatening events. Stopping anti-seizure medicines can lead to seizure recurrence, with studies showing a significant risk following withdrawal (Lamberink et al.; Bonnett et al.).
Similarly, missing immunosuppressant medication after an organ transplant can lead to graft rejection, where the body’s immune system attacks the transplanted organ.
These are not theoretical risks—they are well-recognised outcomes seen in clinical practice.
Why patients should not change the dose themselves
Stopping medication is one issue; adjusting doses independently is another. Even small changes can have significant clinical consequences.
1. Dosing is individualised
The “correct” dose is not based on symptoms alone. It is influenced by factors such as kidney and liver function, body weight, age, drug interactions, blood test results, and clinical monitoring.
A patient who reduces a dose due to side effects, or increases it because symptoms persist, may unintentionally move from under-treatment to toxicity.
2. Narrow therapeutic ranges
Some medicines have a narrow therapeutic range, meaning the difference between a safe and harmful dose is small.
Examples include warfarin, lithium, digoxin, insulin, and methotrexate. For instance, warfarin requires careful monitoring using the INR (International Normalised Ratio) to ensure blood clotting is kept within a safe range. This can be affected by diet, illness, and interactions with other medicines. Small dose changes can increase the risk of either bleeding or clotting.
3. “A bit more” can be dangerous
It is a common assumption that taking slightly more medicine will improve symptoms more quickly. However, this is not always safe.
For example, excess insulin can cause hypoglycaemia (dangerously low blood sugar), which may lead to confusion, loss of consciousness, neurological injury, or death.
4. Methotrexate dosing errors
Methotrexate provides a clear real-world example of how dosing errors can be dangerous. It is usually taken once weekly, not daily.
Errors in dosing frequency have led to serious harm and fatalities, with the Institute for Safe Medication Practices (ISMP) reporting deaths linked to incorrect daily use.
What may appear to be a small change in schedule can, clinically, result in overdose.
Why healthcare advice matters
The message is not “never question your medicines.” Patients should always ask questions. I welcome questioning, and it plays a huge part in making sure the patient is at the centre of every decision I make.
The safer message is: never change medication alone.
Healthcare professionals can assess whether to continue, stop, taper, or switch treatment, and distinguish between side effects, withdrawal, and relapse.
From a pharmacist’s perspective, multidisciplinary care matters. Pharmacists identify interactions and barriers, prescribers manage diagnosis and dosing, and other professionals support monitoring and adherence.
Safe medicine use is a shared responsibility—not an individual burden.
Final thoughts
Patients stop or adjust medicines for understandable reasons—side effects, fear, cost, confusion, and feeling better.
But changing medication without guidance can lead to relapse, withdrawal, stroke, seizures, toxicity, hospital admission, and sometimes death.
The safest step is not silence or guesswork, but conversation—because the right support can turn a risky decision into a safe, informed one.
References:
Bonnett, L.J., Tudur Smith, C., Donegan, S., Marson, A.G. and Chadwick, D.W. (2016) ‘Prognostic factors for time to treatment failure and time to seizure recurrence after withdrawal of antiepileptic drugs in seizure-free patients: A systematic review and individual participant data meta-analysis’, The Lancet Neurology, 15(5), pp. 523–531.
Briesacher, B.A., Gurwitz, J.H. and Soumerai, S.B. (2007) ‘Patients at-risk for cost-related medication nonadherence: A review of the literature’, Journal of General Internal Medicine, 22(6), pp. 864–871.
Gabriel, M. and Sharma, V. (2017) ‘Antidepressant discontinuation syndrome’, CMAJ, 189(21), pp. E747–E747.
Holthuis, A.M., et al. (2022) ‘Risk of ischaemic stroke in patients with atrial fibrillation and non-persistence with direct oral anticoagulants: A real-world study’, Thrombosis Research, 219, pp. 78–84.
Horne, R., Chapman, S.C.E., Parham, R., Freemantle, N., Forbes, A. and Cooper, V. (2013) ‘Understanding patients’ adherence-related beliefs about medicines prescribed for long-term conditions: A meta-analytic review of the Necessity-Concerns Framework’, PLoS ONE, 8(12), e80633.
Kardas, P., Lewek, P. and Matyjaszczyk, M. (2013) ‘Determinants of patient adherence: A review of systematic reviews’, Frontiers in Pharmacology, 4, p. 91.
Lee, S., Jiang, L., Dowdy, D., Hong, Y. and Ory, M. (2023) ‘Attitudes, beliefs, and cost-related medication nonadherence among adults aged 65 or older with chronic diseases’, Preventing Chronic Disease, 20, pp. 1–10.
Lehane, E. and McCarthy, G. (2007) ‘Intentional and unintentional medication non-adherence: A comprehensive framework for clinical research and practice’, International Journal of Nursing Studies, 44(8), pp. 1468–1477.
Lamberink, H.J., Otte, W.M., Geerts, A.T., Pavlovic, M., Ramos-Lizana, J., Marson, A.G., Overweg, J., et al. (2017) ‘Individualised prediction model of seizure recurrence after antiepileptic drug withdrawal following seizure freedom’, The Lancet Neurology, 16(7), pp. 523–531.
NICE (2009) Medicines adherence: Involving patients in decisions about prescribed medicines and supporting adherence. Clinical Guideline CG76. London: National Institute for Health and Care Excellence.
Walsh, C.A., Cahir, C., Tecklenborg, S., Byrne, C., Culbertson, M.A. and Bennett, K.E. (2019) ‘The association between medication non-adherence and adverse health outcomes in ageing populations: A systematic review and meta-analysis’, British Journal of Clinical Pharmacology, 85(11), pp. 2464–2478.
Vrijens, B., De Geest, S., Hughes, D.A., Przemyslaw, K., Demonceau, J., Ruppar, T., Dobbels, F., Fargher, E., Morrison, V., Lewek, P., Matyjaszczyk, M., Mshelia, C., Clyne, W., Aronson, J.K. and Urquhart, J. (2012) ‘A new taxonomy for describing and defining adherence to medications’, British Journal of Clinical Pharmacology, 73(5), pp. 691–705.
World Health Organization (2003) Adherence to Long-Term Therapies: Evidence for Action. Geneva: WHO.
Frishman, W.H. (1987) ‘Beta-adrenergic blocker withdrawal’, American Journal of Cardiology, 59(3), pp. 26F–32F.
Medicines and Healthcare products Regulatory Agency (MHRA) (2020) Methotrexate once weekly for autoimmune diseases: New measures to reduce risk of fatal overdose due to inadvertent daily dosing. London: MHRA.
