Benazepril 40mg to Lisinopril Dose Conversion
Benazepril 40mg is equivalent to lisinopril 20mg, using a 2:1 conversion ratio. 1
Conversion Ratio and Dosing Equivalence
The recommended conversion follows a straightforward 2:1 ratio between benazepril and lisinopril 1:
- Benazepril 10mg = Lisinopril 5mg
- Benazepril 20mg = Lisinopril 10mg
- Benazepril 40mg = Lisinopril 20mg 1
This conversion is based on the maximum recommended doses for both medications, which are 40mg daily for both benazepril and lisinopril in adults 2. The guideline dosing tables confirm benazepril's goal dose range of 20-40mg daily and lisinopril's goal dose range of 20-40mg daily 2.
Clinical Implementation Strategy
Start with lisinopril 20mg once daily when converting from benazepril 40mg. 1 However, in patients who may be at higher risk for hypotension (volume-depleted, on diuretics, elderly, or with renal impairment), consider starting with a lower dose of lisinopril 10mg and titrating up after monitoring 1, 3.
Monitoring Requirements
Check the following parameters within 1-2 weeks after conversion 1:
- Blood pressure to ensure adequate control without excessive hypotension 1
- Serum creatinine and renal function as both ACE inhibitors can affect kidney function 2, 1
- Serum potassium levels to monitor for hyperkalemia, particularly in patients with renal dysfunction or those taking potassium supplements 2, 1
Pharmacokinetic Considerations
Both medications are dosed once daily, making the conversion straightforward from a dosing frequency perspective 2. Lisinopril has a peak effect at 6-8 hours and maintains antihypertensive effects for at least 24 hours 3, 4. The bioavailability of lisinopril is approximately 25% and is not affected by food 3, 4.
Important Caveats
Do not assume all ACE inhibitors convert at the same ratio. 5 Different ACE inhibitors have varying pharmacokinetic profiles and potencies. For example, enalapril and captopril have different dosing frequencies and cannot be simply substituted 5.
Both benazepril and lisinopril share the same maximum daily dose of 40mg 2, but the conversion ratio accounts for differences in their relative potencies at equivalent blood pressure lowering effects 1.
Special Population Adjustments
In patients with renal impairment (creatinine clearance <30 mL/min), dose reduction is necessary for both agents, and closer monitoring is required 3, 6. In heart failure patients, target the higher end of the lisinopril dose range (20-35mg daily) for optimal mortality benefits 1.