Medication adherence: Side effects

Consequences of poor medication adherence include diseases progression, increased morbidity and mortality, reduced effectiveness of certain medications over time, increased healthcare costs, and avoidable hospitalizations and waste. 

Based on literature review, RxLive has created a platform to assist pharmacist interventions related to six major buckets we have classified as the causative factors of medication adherence — cost; side effects; skills; understanding and knowledge; social and behavioral factors; and access to care and burden of regimen. RxLive’s strategies can complement the knowledge and tactics of providers to help their patients overcome adherence issues relating to the side-effects bucket.

Side effects’ deterrence on adherence

Side effects — secondary undesirable effects that can occur during medication therapy — can lead to rational nonadherence, where lack of adherence occurs due to adverse effects. Patients can be deterred from medication adherence if the side effects are intolerable, unmanageable or anticipatorily feared. 

Adverse effects and side effects can manifest in response to an inappropriate dose, incorrect administration, bodily reaction, destruction of other healthy cells, or interactions with other medications or substances. Patients who experience adverse effects may stop the medications, self-adjust their regimen to counter the side effects, or not start their regimen at all. The National Community Pharmacists Association (NCPA) published in Medication Adherence in America that of >1000 survey respondents, 3 in 10 persons with chronic illnesses experienced unpleasant medication side effects, and 21% reported their medication nonadherence was attributed to concerns about side effects. 

How pharmacists can identify adherence issues involving side effects

Pharmacists should be vigilant in assessing and identifying patients in populations that are at greater risk for medication nonadherence due to side effects. Certain populations — older adults, pregnant or breast feeding, those on concomitant therapies or with multiple disease states, infants and young children, or those with certain hereditary factors — are at higher risk for adverse drug reactions due to their capacity to metabolize drugs or by alterations of absorption, elimination or response. Caregivers or patients in these populations have an increased likelihood of experiencing —or previously have experienced — side effects or adverse events that may negatively impact their medication adherence.

Pharmacists can also identify side effects as a barrier to medication adherence through self-report questionnaires, during counseling sessions, and via structured follow-up interviews that assess for various components of adherence. 

How pharmacists can improve medication adherence relating to side effects

Relatedness and connection — According to the NCPA 2013 Medication Adherence in America survey, patient connectedness with their pharmacist or the pharmacy staff was the strongest individual predictor of medication adherence, with 63% of Americans aged 40+ with chronic conditions reporting a sense of connectedness. 

Pharmacists are key healthcare professionals who are knowledgeable and accessible to patients, with the opportunity to identify and address side effect concerns during the initial counselling session when medications are dispensed. Information builds confidence, reduces anxiety, and empowers the patient to make informed-decisions relating to their health. 

Establish relatedness through listening, empathy and sharing information. Attempt to extract the root of patient anxiety regarding side effects, and offer explanations and information to address their concerns. Calmly explain to patients that their specific medication was prescribed to make them better or prevent serious illness, focusing on its positive aspects. Describe what side effects could occur so they are fully aware of what to expect, and encourage them to record any occurrences to share on their follow-up consultation with the pharmacist or physician. Also, suggest calming techniques to prevent triggering the nocebo effect, where negative expectations can create adverse effects; comparable to a reverse placebo effect. 

The Nudge Theory — The Nobel Prize-winning Nudge Theory can be used by pharmacists to improve medication adherence related to side effects barriers. Nudging is based on the premise that rational choices are not always made due to the influence of emotion or personal needs that can lead to less optimal outcomes. 

The ENCOURAGE Trial, using the Nudge Theory, showed that congestive heart failure or diabetic patients had 6 times more positive responses than negative to simple nudges. Nudging can be applied to side effects nonadherence by using informational nudges. These provide scientific and rational logic regarding how medications work for specific patient conditions, how side effects can be managed and are temporary, that serious side effects are rare, and that serious effects regarding a condition can occur without treatment. 

Informational nudges can encourage rational choices. Nudges aren’t mandates; rather, they’re influential suggestions that empower patients to ultimately make their own — and hopefully best — decisions.

Follow-up consultations — Ongoing patient counseling and follow-up by the same pharmacist enables that pharmacist to best understand the patient’s history, social determinants of health (SDOH) and other factors that can lead to the patient not taking medications correctly and thus cause avoidable side effects. For instance, administration methods should be examined to determine if the patient is inadvertently taking the medications with certain foods or substances that worsen side effects. 

Our pharmacists recommend over-the-counter (OTC) treatments or other medications that help mitigate side effects to enable the patient to complete the course of medication. If the side effects are unmanageable, the pharmacist should identify acceptable alternatives and coordinate with the patient’s provider to change the drug therapy. 

Medication therapy management (MTM) — Pharmacist-provided MTM is another strategy to examine if there are drug interactions with the patient’s other prescriptions or OTC medications which could cause side effects or negative outcomes. We work to coordinate with the patient’s physician for alternatives or discontinuance of the medication.

Provide information sources RxLive clinical pharmacists recommend providing digital references in addition to pharmacy material that the patient can access at home. The National Institutes of Health DailyMed provides an in-depth consumer drug guide for prescription and OTC medications that has useful information regarding side effects.

Summary: Avoiding side effects and suboptimal results

Patient’s perceptions or experiences with side effects contribute to the degree of medication adherence. Rational nonadherence can occur secondary to medication use, leading to suboptimal results. Pharmacists are in a prime position to help improve adherence related to side-effect concerns. They are equipped with medication knowledge and patient access, enabling them to inform patients of how their medications work, what side effects to look for, the risk-benefit ratio of the regimen, helping reduce patient anxiety, and suggest alternative therapy when necessary.


Matching Adherence Interventions to Patient Determinants Using the Theoretical Domains Framework. Front. pharmacol.

Medication Adherence in America: A National Report Card. NCPA

Medication Adherence: WHO Cares? Mayo Clin Proc

Factors affecting the development of adverse drug reactions. Saudi Pharm J; Merck Manual

The nocebo effect of drugs. Pharmacol Res Perspect

Author avatar
Kristen Engelen, PharmD
Kristen Engelen, PharmD, is the chief pharmacy officer of RxLive and a certified consultant pharmacist; she has over a decade of experience in retail pharmacy settings. Kristen became an RxLive co-founder because of her passion for geriatric pharmacy, with a focus on the intersection of pharmacy and aging.