Medication Adherence

Benefits of adherence and risks of non-adherence

While oral therapies have been proven to be highly effective and convenient cancer treatments, they are only as successful as your willingness to adhere to them. Your ability to stick to the schedule may depend on your understanding of the treatment regimen, your financial situation and your ability to manage the side effects that accompany many medications.

In fact, the many benefits of these oral anti-cancer drugs can be quickly outweighed by the risks involved when you no longer take your medication as prescribed. Always learn as much as you can about your specific medication, and ask your doctor, nurse or pharmacist for assistance whenever necessary.

Benefits of medication adherence

Anti-cancer medications were once only available to be given through an intravenous (IV) line. Advances in anti-cancer drug research have led to the development of medications that can be given orally. This development offers many benefits compared with IV anti-cancer treatments, most notably, the convenience and comfort of being able to take your anti-cancer medications in your own home, without the need to travel to a hospital or doctor's office. Many new oral anti-cancer drugs are more effective than some IV drugs and are associated with less risk of side effects. Lastly, being able to take anti-cancer medications orally gives patients a sense of greater control over their own care. Many cancers are now considered to be chronic diseases that are managed with oral medications at home, much like other chronic diseases such as diabetes and arthritis.


The effectiveness of anti-cancer drugs is probably the most important factor when patients are considering their treatment options. Patients typically prefer oral treatment to intravenous therapy, but only if the oral treatment has been shown to be as effective as other options. In some cases, it’s not a matter of simply deciding between IV and oral chemotherapy, for example, many include changing treatment types altogether. Recent advancements in some targeted therapy drugs, which target specific mechanisms of cancer cell growth, offer many cancer patients a more effective treatment option than conventional chemotherapy. These drugs usually come with fewer side effects as well.

Convenience and comfort

Two highly significant benefits of oral treatment include their convenience and their ability to keep you more comfortable than other options. Patients who take oral anti-cancer drugs can cut back considerably on traveling for treatment, and spend considerably less time in the doctor’s office or hospital. While also avoiding the needle sticks associated with IV therapies, patients who take oral drugs get to spend more time with their friends and family and encounter fewer interruptions to their daily life. This type of treatment does come with more patient responsibility, however, as the responsibility of taking the right drug at the right time in the correct way shifts from the health care team to you and your caregivers. Feeling overwhelmed is common because it’s often difficult to fully understand how to take your anti-cancer drugs correctly and safely for the entire duration of your treatment plan.


Many cancer patients feel empowered when they have control over their treatment regimen, and this can improve their overall sense of well-being. That can often lead to better decision-making abilities regarding health and wellness and their treatment in general.

“I feel like as long as I continue taking hormone therapy drugs, I’m still actively fighting cancer,” said Dr. Oliver Bogler, a male breast cancer survivor, who was diagnosed in 2012 and continues to take hormone therapy. “That’s more comforting and encouraging to me than doing nothing and feeling helpless.”

Treatment regimens are the most beneficial if decisions are shared by you and your health care team, so communicate often to make sure you’re all on the same page. Patients should never make changes to their treatment plan unless instructed to do so by their doctor.

Common reasons for non-adherence to oral anti-cancer drugs

  • Forgetfulness
  • Attempt to avoid side effects
  • Complex treatment schedule
  • Several daily medications
  • Misunderstanding of drug instructions
  • High drug cost
  • Treatment fatigue
  • Misunderstanding of treatment
  • Lack of confidence in the treatment
  • Feeling well enough to skip doses
  • Presence of other illnesses or conditions
  • Depression
  • Cognitive impairment
  • Functional difficulties (inability to open drug containers, poor vision, difficulty swallowing)
  • Inadequate follow-up with health care team

Potential risks of non-adherence

Medical non-adherence can have a serious impact on a patient’s cancer care and can lead to increased side effects, unnecessary changes to the treatment plan, hospitalization and poor outcomes. It’s dangerous when patients deviate from their original plan without being told to do so by their doctor. Patients can misunderstand the instructions, accidentally skip a dose, deliberately stop refilling their prescriptions or take less than recommended.

Poor treatment outcome

The most serious consequence of medical non-adherence is running the risk that your treatment will be ineffective. Studies show that not taking anti-cancer medication as prescribed by a doctor can lead to cancer progression or recurrence. Because of how the drugs work, even small alterations to a treatment regimen can lead to failure.

Increased side effects

The amount of anti-cancer drugs in your system can influence the amount and severity of the side effects you encounter. Too much medication in your system may be caused by:

  1. Doses taken too close together – Patients might double up after missing a dose or get confused by their treatment regimen.
  2. Drug interactions – Drug interactions can result when your anti-cancer medication reacts with certain other medications, supplements or foods. You should talk to your health care team about potential drug interactions and pay attention to any known interactions listed on your prescription.
  3. Intentional “overadherence” – Overadherence can occur when a patient takes more medication than prescribed, believing that a higher dose can increase the drug’s effectiveness. While this is less common than non-adherence, it can still be equally as dangerous.

Unnecessary changes in treatment

When patients reduce or quit taking their anti-cancer medication without telling their health care team, the doctor may think the lack of response is because the treatment is ineffective. On the other hand, if a patient takes too much medication and suffers from increased side effects, the doctor may believe the patient is unable to tolerate the drug. These misunderstandings can result in unnecessary diagnostic tests, unwarranted dose changes or a switch to a new drug altogether. All of these factors can cause patients to miss out on what otherwise might have been the best treatment option available to fight their cancer type.