Hello, Thanks for posting your query on Healthcare Magic... * Brief Answer: Lisinopril is a long acting drug should be once daily. it may be needed to add another drug at night. *Explanation: My opinion is that high blood pressure on many occasions is an indication for control .That happens on many levels. First, be sure that high blood pressure is not secondary to any other diseases as Cushing or renal failure.Then ,Diet with low salt and less fat content is crucial. Exercise and other healthy activities are also a mean to control blood pressure. If all that dose not help, medications are a must .That is usually decided by your doctor according to your condition and comorbidities .Some drugs that are perfect for patients are not necessary good for others.Regular blood pressure monitoring is as important as starting treatment so that we could assess efficacy of the medication we started. I suggest my patients the following : take lisinopril once in the moring , add another drug at night according to their age gender and risk factors The information provided by you is not sufficient to provide a good opinion. If someone comes to me with this condition I would ask them about other comorbidities like diabetes, hyperlipidemia etc. *Conclusion: I suggest you stick to a low salt diet and consult your physician about your grandma s medication. If you have any further questions I will be happy to help, If not, you can close the discussion and rate the answer. Wish you good health.