PACE Case: Further Reducing the Risk of ADEs in a Participant with a Low MedWise Risk Score™

Challenge
AP is an 85-year-old male with a past medical history of hypertension, benign prostatic hyperplasia (BPH) with an enlarged prostate, peripheral vascular disease, atrial fibrillation, and vitamin D deficiency. His MedWise Risk Score™ at the time of the medication safety review was 6 out of 50, which is categorized as low risk. Despite the participant’s low risk, a polypharmacy consultation was requested by the prescriber to optimize the participant’s medication regimen and reduce the risk of adverse effects, such as a detrimental fall.

Participant Risk Score

The participant’s medication regimen includes:

  • Bisoprolol/HCTZ 10-6.25mg daily
  • Cholecalciferol 5,000 IU daily
  • Doxazosin 8mg daily
  • Rivaroxaban 20mg daily
  • Tamsulosin 0.4mg daily

During a polypharmacy call with the PACE prescriber, the following medication-related problems were addressed by the CareKinesis clinical pharmacist:

  • The participant is on bisoprolol/HCTZ 10-6.25mg and doxazosin 8mg for hypertension, and tamsulosin 0.4mg for BPH. Given his advanced age and recent blood pressure readings averaging around 120/70-80mmHg, he may be at a higher risk for orthostatic hypotension and falls from concomitant use of these medications. Non-selective alpha-blockers, such as doxazosin, are not recommended for the treatment of hypertension in older patients, and are outlined in the Beers List of Potentially Inappropriate Medications. Furthermore, the use of tamsulosin and doxazosin could be considered duplicate therapy as they have similar mechanisms of action, even though they have different selectivity and are used for two separate indications.
  • Tamsulosin is a selective-alpha blocker that acts quickly to treat symptoms of BPH, but does not decrease the prostate size. As a result, the participant’s BPH prognosis may worsen over time. In addition, the participant’s hydrochlorothiazide, which is a diuretic, may be aggravating his BPH symptoms.
  • The participant is also currently taking cholecalciferol 5,000 units daily for his vitamin D deficiency. However, his most recent 25-OHD was 8.4 ng/mL, which is considered low. This is concerning as the participant’s low vitamin D level combined with his risk of falls due to orthostatic hypotension may increase his risk for fractures.

Recommendations
The CareKinesis pharmacist proposed several recommendations to optimize the participant’s current treatment regimen and mitigate risks of medication-related adverse effects, including falls and possible fractures.

  • Consider discontinuing doxazosin and switching bisoprolol/HCTZ to a first-line antihypertensive agent such as an ACE-inhibitor (ACEI), an angiotensin receptor blocker (ARB), or a calcium-channel blocker. A non-dihydropyridine calcium-channel blocker, such as diltiazem*, could also be used for rate control for the participant’s atrial fibrillation.
  • Consider initiating finasteride, a 5-alpha reductase inhibitor, to decrease prostate size and improve the participant’s symptoms and disease prognosis. The participant’s PSA levels should be evaluated at the start of therapy initiation and in 3 to 6 months to ensure efficacy. Then, in 6 to 12 months, when response seen with finasteride, the participant may be able to attempt a discontinuation trial of tamsulosin.

*NOTE: The concentrations of finasteride (if initiated), tamsulosin, and rivaroxaban may be higher than expected if concomitantly administered with diltiazem due to competitive inhibition of CYP3A4. As a result, the participant will have an increased risk of toxicity from finasteride, tamsulosin (contributing to orthostatic hypotension), and rivaroxaban (contributing to bleeding).

  • Consider increasing cholecalciferol to 50,000 intl units per week for a duration of 8 to 12 weeks, with a goal 25-OHD ≥ 30 ng/ mL.

Benefit/Outcome
The PACE prescriber agreed that bisoprolol/HCTZ and doxazosin were not optimal agents for the treatment of hypertension and that discontinuing them would benefit the participant in consideration of orthostatic hypotensive risks. The prescriber decided that it would be best to initiate the participant on diltiazem for dual hypertension and rate control therapy. Diltiazem will be administered at bedtime to mitigate the competitive inhibition interaction with finasteride, tamsulosin and rivaroxaban. While this does increase the participant’s administration times to 3x/day, the participant is adherent to his medications and is not anticipated to have difficulty taking diltiazem. Calcium channel blockers have also been found to be more effective when administered at bedtime.

The prescriber decided to initiate the participant on finasteride, re-evaluate tamsulosin therapy in 6 to 12 months, and increase the cholecalciferol dose to 50,000 units weekly. Labs would be monitored closely for improvement in PSA and 25-OHD levels. The participant will continue to be closely monitored for orthostatic hypotension and potential dizziness.

Conclusions/Lessons Learned
This case study demonstrates that even those with low MedWise Risk Scores can benefit from MedWise Safety Reviews for medication safety optimization. After discussing potential medication-related risks and duplicate therapies with the CareKinesis clinical pharmacist, the PACE prescriber agreed to make the discussed changes to the participant’s medication regimen to help reduce the participant’s risk of falls and fracture. The participant’s hypertension and BPH regimens were optimized with safer alternatives and his vitamin D deficiency supplement was adjusted in accordance to the participant’s most recent labs. While the participant’s MedWise Risk Score was reduced from 6 (low) to 5 (very low), the specified medication changes have mitigated the participant’s overall risk of potential complications, such as a detrimental fall with or without a fracture. The PACE clinical pharmacist will continue to work closely with the PACE prescriber to assess the participant’s risks and pharmacotherapy needs and make appropriate modifications, as necessary.

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