Hi, first post. Dad has been prescribed this drug after HA 10 days ago. He takes 10 mg at 10 am and 10 mg at 1 pm. He is himself without taking the drug but in the afternoon he has severe headaches - it is debilitating for him. It is distressing to see him suffer so badly. We have read that the headaches should become less over time, but so far can’t see any evidence. He is 81 years old. In need of advice
Thank you