Is there any way to get a 6-month prescription for blood pressure medication?

I have been taking blood pressure medication for 5 years. Due to the nature of my job, I move around frequently, so I haven't been able to receive consistent prescriptions from a single hospital, and I don't have a regular clinic to ask for help, which is quite difficult. I need at least 6 months' worth because of a business trip to the US, and I'm even considering buying a 3-month supply and splitting the pills in half, but it's a tough situation.