Hi, Diltiazem belongs to the group of medications known as calcium channel blockers that is used in the treatment of high blood pressure, angina and certain heart arrhythmias. It is usually advisable not to stop taking Diltiazem abruptly as stop taking this medication suddenly may cause anyone s condition worse. Stopping Diltiazem abruptly may cause the blood pressure to rise, aggravate angina or worsen sinus tachycardia and this may increase the risk of developing heart attack or stroke. But, if your doctor has suggested you to stop this medication due to its side effects like pain in the arm, lack of sleep or insomnia, then you should follow your doctor s advice for your betterment. If you have any query, then you should consult your doctor. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Zubayer Alam, General And Family Physician,