Amitriptyline, sold under the brand name Elavil among others, is a tricyclic antidepressant primarily used to treat cyclic vomiting syndrome (CVS), major depressive disorder and a variety of pain syndromes from neuropathic pain to fibromyalgia to migraine and tension headaches. Due to the frequency and prominence of side effects, amitriptyline is generally considered a 
second-line therapy for these indications.The most common side effects are dry mouth, drowsiness, dizziness, constipation, and weight gain. Of note is sexual dysfunction, observed primarily in males. Glaucoma, liver toxicity and abnormal heart rhythms are rare but serious side effects. Blood levels of amitriptyline vary significantly from one person to another, and amitriptyline interacts with many other medications potentially aggravating its side effects. Amitriptyline was discovered in the late 1950s by scientists at Merck and approved by the US Food and Drug Administration (FDA) in 1961. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2019, it was the 94th most commonly prescribed medication in the United States, with more than 8 million prescriptions. Medical uses
Amitriptyline is indicated for the treatment of major depressive disorder and neuropathic pain and for the prevention of migraine and chronic tension headache. It can be used for the treatment of nocturnal enuresis in children older than 6 after other treatments have failed. Depression
Amitriptyline is effective for depression, but it is rarely used as a first-line antidepressant due to its higher toxicity in overdose and generally poorer tolerability.
Diagnosis
The hallmark features of this syndrome are poorly developed fingernails, toenails, and patellae (kneecaps). Sometimes, this disease causes the affected person to have either no thumbnails or a small piece of a thumbnail on the edge of the thumb. The lack of development or complete absence of fingernails results from the loss of function mutations in the LMX1B gene. This mutation may cause a reduction in dorsalising signals, which then results in the failure to normally develop dorsal specific structures such as nails and patellae. Other common abnormalities include elbow deformities, abnormally shaped pelvic (hip) bones, and kidney disease. Treatment
Treatment for NPS varies depending on the symptoms observed. Perform screening for kidney disease and glaucoma, surgery, intensive physiotherapy, or genetic counseling. ACE inhibitors are taken to treat proteinuria and hypertension in NPS patients. Dialysis and kidney transplant. Physical therapy, bracing and analgesics for joint pain. See also
List of cutaneous conditions
List of radiographic findings associated with cutaneous conditions

References
External links
GeneReview/NCBI/NIH/UW entry on nail–patella syndrome