Can The Same Dosage Of Atenolol Be Taken Twice A Day To Keep The Medication From Wearing Off?

I have been taking atenolol 25mg for over 10 years for tachycardia and pvc's. In the last couple of months I am having increased problems with increased pvc's and rapid heart rate at night. I was wondering if it is okay for me to take 1/2 in the morning and 1/2 at night to keep the medication from wearing off.