Avoid cutting, crushing or chewing this medicine. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Turn to your doctor or pharmacist for more details. Turn to your doctor or pharmacist for more details. The most common side effects are dizziness, drowsiness, lightheadedness, confusion, agitation, increased anxiety, etc. Before taking Doxepin tell your doctor or chemist if you are allergic to it; or if you have other allergies. If you think you have used too much of this medicine seek emergency medical attention right away.