Was it a good choice to stop chlorthalidone (a diuretic) abruptly in my grandmother with poorly controlled hyperglycemia (high blood sugar) after long-term use?

Abrupt Discontinuation of Chlorthalidone in Elderly Patient with Poorly Controlled Hyperglycemia

Abruptly stopping chlorthalidone in your grandmother with poorly controlled hyperglycemia was not the optimal decision, as this creates risks of rebound hypertension while alternative management strategies would have been safer.

Risks of Abrupt Discontinuation

Abrupt discontinuation of diuretics like chlorthalidone can lead to several adverse outcomes:

• Rebound hypertension: Sudden withdrawal of antihypertensive medications can cause blood pressure to rise rapidly 1
• Fluid retention: May occur quickly after stopping the medication, potentially worsening any underlying cardiovascular conditions
• Electrolyte imbalances: Sudden changes in medication can disrupt the body's electrolyte balance that had adapted to long-term use

Chlorthalidone and Hyperglycemia Concerns

Your concern about hyperglycemia is valid, as thiazide-type diuretics like chlorthalidone can affect glucose metabolism:

• Chlorthalidone can increase fasting glucose levels (approximately 8.5 mg/dL at 2 years of treatment) 2
• Diuretic-treated patients show a 15-40% greater incidence of new-onset diabetes compared to patients on other antihypertensive medications 1
• The diabetogenic effect is a legitimate concern, especially in patients with pre-existing glucose metabolism issues 3

Better Approach for Management

Instead of abrupt discontinuation, consider these evidence-based approaches:

1. Dose reduction: Lower doses of chlorthalidone (12.5 mg/day) can maintain blood pressure control while minimizing metabolic side effects 4

2. Gradual tapering: Step-down treatment allows for monitoring of blood pressure response and reduces withdrawal effects 4

3. Medication substitution: Consider switching to an alternative antihypertensive with better glycemic profile:

   • ACE inhibitors or ARBs are preferred alternatives for patients with diabetes 5
   • Calcium channel blockers can also be considered as first-line alternatives 5

4. Comprehensive monitoring: Regular monitoring of:

   • Blood pressure (to detect rebound hypertension)
   • Serum electrolytes (especially potassium)
   • Blood glucose levels

Special Considerations for Elderly Patients

For elderly patients with diabetes and hypertension:

• The primary goal is to prevent hypoglycemia while managing hyperglycemia 1
• Individualized HbA1C targets should balance benefits against hypoglycemia risk 1
• In elderly patients, the risk of uncontrolled hypertension may outweigh the diabetogenic effects of diuretics 1

What To Do Now

Since chlorthalidone has already been discontinued:

1. Immediate monitoring: Check your grandmother's blood pressure frequently to detect any rebound hypertension

2. Medical consultation: Consult with her physician as soon as possible to:

   • Assess current blood pressure status
   • Evaluate glucose control
   • Consider alternative antihypertensive therapy with better glycemic profile

3. Medication options: Discuss with her physician about:

   • ACE inhibitors or ARBs (better metabolic profile for diabetic patients)
   • Calcium channel blockers (metabolically neutral)
   • Lower dose chlorthalidone if other options aren't suitable

Conclusion

While concerns about chlorthalidone's effect on glucose control are valid, abrupt discontinuation creates risks that could have been avoided through a more measured approach of dose reduction, gradual tapering, or supervised medication substitution. Contact your grandmother's healthcare provider promptly to establish appropriate antihypertensive therapy.