A Case Study

Prescribing cascades occur when a medicine causes a side effect that gets misdiagnosed as a new condition. A new prescription medicine is then added to treat the side effects of the initial medicine.

Prescribing cascades can occur in a variety of medicines. When a patient presents with new symptoms, it’s important to inquire about their medication history and include any potential adverse drug reactions (side effects from medicines) in their differential diagnosis. These cascades can result in unnecessary diagnoses and treatment, increased risk of drug interactions, side effects and complications.

In this post, I want to share a clinical example of a prescribing cascade that I noticed in one of my patients.

Antidepressants

Antidepressants like SSRIs and SNRIs can cause a variety of side effects. Whenever I counsel patients, I always mention the following side effects with these medicines:

• Sleep disturbances — insomnia, drowsiness/sedation
• GI related — dyspepsia, nausea, diarrhea, dry mouth
• Sexual dysfunction — decreased libido, erectile dysfunction, anorgasmia
• Other — headache, dizziness, agitation, anxiety, weight gain, suicide ideation

As you can see, the side effects are vast and there are plenty of opportunities for prescribing cascades to arise. Let’s examine a clinical case I came across in my own practice:

Case Study

John Doe (JD), a 40-year-old male patient, was treated for major depressive disorder with Fluoxetine 20mg once daily.

Within 12 weeks of initiating therapy, JD experienced significant dyspepsia, upset stomach and presented to his family physician. His physician diagnosed him with gastroesophageal reflux disease (GERD) and prescribed a proton pump inhibitor (PPI), Pantoprazole 40mg once daily.

A side effect of PPIs is that they can lead to malabsorption of nutrients and deficiencies in essential vitamins and minerals, such as Vitamin B12 deficiency.

JD continued on both medicines for 12 months. During his annual check-up, he complained of fatigue and difficulty concentrating. Unaware that this may have been a side effect from his PPI and potentially Vitamin B12 deficiency, JD and his physician attributed his symptoms to worsening depression and increased his Fluoxetine dose.

Fluoxetine —> Upset Stomach —> Pantoprazole —> B12 Deficiency —> Fatigue = “Worsening depression” —> Increase dose of Fluoxetine

It was only by chance that we were able to recognize a potential prescribing cascade. JD had brought in his new prescription for Fluoxetine. During our counseling session, I began probing about his initial diagnosis of depression and how he was doing on the medicine up until this point. He gave the standard response — “good” — I could tell he just wanted to get his prescription and leave (nobody wants to wait at the pharmacy).

Ignoring his request to wrap it up and tell him to take his medicine with or without food, I dug a bit deeper. I suggested he establish some clear goals of medication therapy, as a way to ensure we can objectively measure his response to the new dose of Fluoxetine. He was intrigued. We kept digging and I conducted a brief review of his medication history. We switched the conversation over to his Pantoprazole.

JD mentioned he had begun the Pantoprazole a few weeks after starting his Fluoxetine. Red flag. With all this new intel, I sent a fax to his physician suggesting a drug holiday and provided a taper plan to get JD off his Pantoprazole.

His physician obliged and within 3 months, JDs symptoms had improved. He was no longer taking Pantoprazole and his fatigue and focus had improved. It may have been the increased dose of Fluoxetine, I’m not sure. But one thing I know for certain is that his pill burden was reduced and he’s in a better state than he was before we spoke.

The Root Cause

I’ve been pondering why prescribing cascades tend to flousish in our healthcare system. I believe most of the cases can be attributed to:

• Poor communication between patients and healthcare providers. Patient’s fail to adequately explain and provide full information to clinicans.
• Lack of time — Physicians have limited time with their patients, therefore things are missed when obtaining medical histories.
• Patient expectations — they expect to get instant relief and solutions to help fix their symptoms of concern. This can put pressure on physicians to prescribe medicines, instead of focusing on lifestyle interventions.
• Inadquate follow up and education — physicians prescribe medicines, pharmacists dispense and provide medication counseling. It’s part of our job to ensure patients have the knowledge and awareness of the key side effects to monitor for.

This prescribing cascade could have been avoided if we initially recognized the patients GI symptoms as a potential side effect from his Fluoxetine. Instead of adding on a new medicine, we could have adjusted the Fluoxetine dose or considered switching to another antidepressant.

I can’t help but feel that this is a common theme with antidepressants. As more and more patients get prescribed these medicines, I can’t help but think about all the potential prescribing cascades going undetected.

I remain hopeful for the future. My mission with B.U.D.S and this blog is to continue to shed more light and focus on patient safety and preventive medicine. As pharmacists, we need to take a proactive approach in leading this change. After all, we are medication experts, and part of that responsibility is to ensure safe prescribing and establishing appropriateness of drug therapy. More than ever, our patients are depending on us.

Thanks for reading.

Much love

P.S. If you or anyone you know is interested in coming off their meds or learning more about deprescribing, click on “Work with Shawn” at the top of the site, or you can fill out the form below to contact me directly.

May you be happy and healthy.

SG