I know most drugs have side effects. What are the side effects with a topical agent called glyceryl trinitrate? I'm going to use skin patches with this for a chronic Achilles tendon problem.

Glyceryl trinitrate (GTN) is a prescription drug used on skin patches to promote healing. Scientists are finding many uses for GTN. It has been (and still is) being used for chest pain from heart disease.

It's also being used for cracked and bleeding skin, torn tendons Up to one-third of people using GTN ointment have throbbing headaches. These headaches often go away after two to three days even if you continue to use the ointment. If you get these headaches it could be that you are applying too much cream. Check with your doctor about this. Sometimes just using less cream is all that's needed, but your doctor must make this decision.

Other patients get a skin rash from the cream. They may have an allergic sensitivity and can't use the cream. Patients who use GTN for other conditions may have other side effects. Headaches and skin rash are the two most common problems with GTN for tendon problems.

Call your doctor right away if you have any new symptoms that start after using GTN. You may not have to quit using the ointment, just change the way you're using it.