Ramipril with Lithium

Please can you advise me.  I have been told by my GP that I need to take blood pressure medication.  He has prescribed me Ramipril.  However the pharmacist has told me this is not the best medication as it can interact badly with lithium.  I was ill last year and I am scared of knocking my lithium levels.  Apparently I should not take diuretics,

Can you please recommend something safe for me to take to reduce my blood pressure. 

Thankyou

Lindsey Maher