When used for long periods of time without a break, some people develop a physical need
to continue taking
Nitroglycerin Patch. This is known as physical DEPENDENCE. Do not suddenly stop taking Nitroglycerin Patch without your doctor's approval. Stopping Nitroglycerin Patch suddenly may cause serious, possibly life-threatening, WITHDRAWAL symptoms, including chest pain and heart attack. Having a nitrate-free period each day will help prevent tolerance, dependence, and withdrawal problems.