The fat pad in your knee sits just below your knee cap and provides cushioning and shock absorption between the bones of your knee joint. It is also known as Hoffaâs pad and is one of the most sensitive components of your knee joint. Pain is most often caused by the fat pad becoming pinched between the end of your thigh bone and your kneecap.
For example, amitriptyline can cause nervousness, insomnia, and anxiety in some patients because it can stimulate the nervous system. In addition, amitriptyline can also block the effects of a chemical known as acetylcholine, which is used by nerves to control muscles, eMedTV reports.
Serious Side Effects of Amitriptyline. Tell your doctor or go to an emergency room right away if you experience any of the following serious side effects: Slow or difficult speech. Dizziness or faintness. Weakness or numbness of an arm or a leg. Crushing or heavy chest pain. Rapid, pounding, or irregular heartbeat. Severe skin rash or hives.