If you have high blood pressure and are already taking Prolomet (metoprolol) regularly, experiencing fast heartbeats when you miss a dose is quite common, because this medicine helps control heart rate. However, it is not safe to take Depin 5 mg (nifedipine) on your own as an as-needed medicine for such episodes. Depin works differently and can suddenly lower your blood pressure, which may cause dizziness, fainting, or even worsen heart symptoms if not used properly. The better approach is to take your regular medicines on time every day and avoid missing doses. If you still get palpitations despite regular use, or if missed doses are frequent, you should consult your doctor; your treatment plan may need adjustment (for example, a dose change or a longer-acting medicine). In the meantime, try to set reminders for your medications, reduce caffeine, and manage stress. If you ever have severe palpitations, chest pain, or dizziness, seek medical care immediately.