Hi, i have gone through your question and want you to know that Nuvigil is trade name of drug armodafinil which is a medication that promotes wakefulness. It is approved for treatment of excessive day time sleepiness. If you had walked into my clinic i would have Known your Age and would have taken history of any hypertension, Diabetes, Panic attack, chest pain, thyroid disorder. The cause of Rapidly beating heart and anxiety in your case may be- Overdose of Nuvigil- It presents as severely increased or decreased heart rate, chest pain, and increased blood pressure. Panic Attack- It can also present as rapidly beating heart, difficulty in breathing and anxiety. Acute Exacerbation of Asthma- Acute attack of asthma too may have similar features. Heart disease- heart diseases may also present with difficulty in breathing, increase heart rate and tightness in chest. To differentiate between them i would order some investigations. To rule out any heart disease i would order Chest X- Ray ECG and ECHO. I would also advice fasting and post postprandial blood sugar level. I would also advice my patient to breath into a paper bag which is covering their nose and mouth if these symptoms occur after a stressful event (for panic attack) and if possible to do some yoga and meditation. I would also like to take history of asthma medication my patient is taking and would like to auscultate my patients chest to look for wheezing (it is a sound which comes from chest when you hear the chest using stethoscope) and would also like to know if these symptoms become worse with change in season. I would also like to know the dose of Nuvigil you are taking and whether or not it is the right dose. Once i have found out the cause of your symptoms i would advice medication for that particular condition. If it is due to over dosage Nuvigil i would lower the dose of Nuvigil and if it is panic attack i would advice breathing exercise through paper bag. For asthma and heart problem specific medications are to be given.