From the Guidelines
To better manage this patient's stage 2 hypertension, I recommend optimizing the current treatment regimen and adding a low dose of spironolactone as the 4th line agent, given that the patient's serum potassium and eGFR are within acceptable limits, as suggested by the 2020 International Society of Hypertension Global Hypertension Practice Guidelines 1. The patient's blood pressure of 143/86 mmHg indicates that her current monotherapy with Cardizem 420mg extended release is insufficient for adequate control. Given the patient's complex medication regimen, it is essential to consider potential drug interactions and optimize the current treatment regimen before adding new medications. The patient's current medications, including Polyethylene Glycol 3350, Ferrous Sulfate, Dilantin, Pravastatin Sodium, Dexilant, Alendronate Sodium, and Ativan, do not appear to have significant interactions with spironolactone. However, careful monitoring of serum potassium levels is necessary when adding spironolactone to the patient's regimen. Additionally, I recommend lifestyle modifications, including sodium restriction to less than 2.3g daily, regular physical activity (30 minutes of moderate exercise most days), and weight maintenance, as suggested by the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults 1. The patient should monitor her blood pressure at home twice daily for two weeks and return for follow-up in 4 weeks to assess the effectiveness of this regimen. If blood pressure remains above target (<130/80 mmHg for a patient of this age), we may need to consider alternative treatment options, such as adding an ACE inhibitor or ARB as a third agent, though careful monitoring for orthostatic hypotension would be necessary given her age and multiple medications. Key lifestyle modifications to recommend include:
- Weight loss, aiming for a 1-kg reduction in body weight, which can lead to approximately 1 mm Hg reduction in systolic blood pressure for every 1-kg reduction in body weight 1
- Healthy diet, such as the DASH dietary pattern, which can lead to approximately 11 mm Hg reduction in systolic blood pressure 1
- Reduced intake of dietary sodium, aiming for less than 1500 mg/d, which can lead to approximately 5/6 mm Hg reduction in systolic blood pressure 1
- Enhanced intake of dietary potassium, aiming for 3500–5000 mg/d, which can lead to approximately 4/5 mm Hg reduction in systolic blood pressure 1
- Physical activity, such as aerobic exercise, dynamic resistance, or isometric resistance, which can lead to approximately 5/8 mm Hg reduction in systolic blood pressure 1
From the FDA Drug Label
PRECAUTIONS General Diltiazem hydrochloride is extensively metabolized by the liver and excreted by the kidneys and in bile. As with any drug given over prolonged periods, laboratory parameters of renal and hepatic function should be monitored at regular intervals.
Drug Interactions Due to the potential for additive effects, caution and careful titration are warranted in patients receiving diltiazem hydrochloride concomitantly with any agents known to affect cardiac contractility and/or conduction
The patient is currently taking Diltiazem 420mg extended release once daily for stage 2 hypertension. To better manage blood pressure, consider the following plan of care:
- Monitor renal and hepatic function at regular intervals due to the potential for additive effects with other medications.
- Carefully titrate the dose of diltiazem, if necessary, to avoid potential interactions with other medications that affect cardiac contractility and/or conduction.
- Consider alternative medications or dose adjustments for concomitantly administered medications, such as statins, to minimize the risk of adverse effects.
- Continue to monitor the patient's blood pressure and adjust the treatment plan as needed to achieve optimal blood pressure control 2.
- Also, note that the patient is taking Pravastatin Sodium 10mg Tablet which is a statin, and according to the drug label, diltiazem is an inhibitor of CYP3A4 and has been shown to increase significantly the AUC of some statins. However, in the same study, there was no significant change in 20 mg single dose pravastatin AUC and Cmax during diltiazem coadministration 2.
From the Research
Patient Assessment
The patient is a 69-year-old female with stage 2 hypertension that has not improved over the past three months. She is currently taking Cardizem 420mg extended release once daily, along with other medications for constipation, anemia, seizures, cholesterol, GERD, osteoporosis, and anxiety.
Current Medications
- Polyethylene Glycol 3350 17g Powder for Solution
- Ferrous Sulfate 325mg Enteric Coated Tablet
- Dilantin 100mg Extended Release Capsule
- Pravastatin Sodium 10mg Tablet
- Dexilant 60mg Delayed Release Capsule
- Alendronate Sodium 70mg Tablet
- Ativan 2mg Tablet
- Cardizem 420mg extended release once daily
Vital Signs
- Temperature: 97.9 F
- BP Systolic/Diastolic: 143/86 mmHg
- O2 Saturation: 96% Room air
- Respiration: 18/min
- Pulse: 80/min
- Height: 5' 1''
- Weight: 119.2 lbs
- BMI: 22.5
Plan of Care
To better manage the patient's blood pressure, the following steps can be taken:
- Lifestyle modification, including weight loss, healthy dietary pattern, physical activity, and moderation or elimination of alcohol consumption 3
- Consider adding a thiazide or thiazide-like diuretic, an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, or a calcium channel blocker to the patient's medication regimen 3, 4
- Monitor the patient's blood pressure regularly and adjust the medication regimen as needed to achieve a target blood pressure of <130/80 mmHg 3
- Consider using combination therapy, which has been shown to be effective in achieving blood pressure control 5, 4, 6
- Be aware of the potential side effects of antihypertensive medications, such as ankle edema, and monitor the patient for these effects 5
Considerations
- The patient's age and comorbidities should be taken into account when selecting antihypertensive medications 3, 4
- The patient's current medication regimen should be reviewed for potential interactions or contraindications with new antihypertensive medications 3, 4
- The patient's blood pressure should be monitored regularly to assess the effectiveness of the treatment plan and make adjustments as needed 3, 6