Is your doctor adjusting the medication?
Hawthorn is an excellent plant to help regulate blood pressure. In Canada, it is named Heart Care from A.Vogel. It helps increase low blood pressure and decrease high blood pressure, but it is a plant that works very gradually: it can take 1-3 months to get the full impact.
You should not make any changes to your medication unless the doctor recommended it, but you should monitor your blood pressure every day and keep a journal to show your doctor if needed. Many drug stores have blood pressure machine available for public use.
See the following text for further information on Low blood pressure or hypotension.