Switching from Perindopril to Telmisartan for ACE Inhibitor-Induced Cough in a 90-Year-Old Male
For a 90-year-old patient with cough from perindopril, switching to telmisartan 40 mg once daily is recommended as the optimal starting dose, with careful monitoring for blood pressure control and renal function. 1, 2
Rationale for Switching to an ARB
- ACE inhibitor-induced cough is a common side effect occurring in 10-20% of patients on medications like perindopril, characterized by a dry, persistent cough that typically begins within days to weeks after starting the medication 1
- The cough is caused by the accumulation of bradykinin and substance P due to ACE inhibition, and the only uniformly effective treatment is discontinuation of the ACE inhibitor 1
- Angiotensin receptor blockers (ARBs) like telmisartan are the preferred alternative for patients with ACE inhibitor-induced cough as they do not inhibit ACE and therefore don't cause bradykinin accumulation 1, 3
- Switching from an ACE inhibitor to an ARB is strongly recommended (Grade A recommendation) when ACE inhibitor-induced cough occurs 3
Telmisartan Dosing for a 90-Year-Old Patient
- For a 90-year-old patient, the recommended starting dose of telmisartan is 40 mg once daily 4, 2
- Telmisartan has a long half-life of approximately 24 hours, allowing for effective once-daily dosing 2
- The pharmacokinetics of telmisartan do not differ significantly between elderly patients and those younger than 65 years, so no initial dose adjustment is required based on age alone 2
- Telmisartan 40-80 mg/day has been shown to be effective for blood pressure control, with maximum blood pressure reduction occurring within this dosage range 5
Monitoring Recommendations
- Monitor blood pressure, renal function, and potassium levels within 1-2 weeks after initiating telmisartan 3
- Pay particular attention to postural blood pressure changes in elderly patients 3
- If blood pressure control is inadequate on 40 mg daily, the dose can be increased to 80 mg daily, which is the maximum recommended dose for telmisartan 4, 2
- In comparative studies, telmisartan has shown similar efficacy to other antihypertensive agents with a tolerability profile similar to placebo 5
Important Precautions
- Although rare, angioedema has been reported with ARBs in patients who previously experienced angioedema with ACE inhibitors; use caution during initial treatment 3
- Assess renal function regularly, as ARBs can cause hyperkalemia and worsening renal function similar to ACE inhibitors 3
- Studies have shown that switching from perindopril to telmisartan does not significantly affect renal function parameters including blood urea, serum creatinine, and creatinine clearance 6
- Telmisartan has been shown to cause significantly fewer treatment-related side effects compared to ACE inhibitors (28% vs 40%), particularly regarding cough (3% vs 7%) 7
Expected Outcomes
- The cough from perindopril should resolve within 1-4 weeks after discontinuation, though it may take up to 3 months in some cases 1
- Telmisartan has demonstrated efficacy in reducing systolic blood pressure by 15.6-17.9 mmHg in patients with isolated systolic hypertension, which is common in elderly patients 8
- In comparative studies, telmisartan has shown similar efficacy to hydrochlorothiazide in reducing systolic blood pressure with a tolerability profile similar to placebo 8