Clinical indications for indometacin include:Joint diseases

rheumatoid arthritis
ankylosing spondylitis
osteoarthritis
gouty arthritis
acute painful shoulder bursitis or tendinitisHeadaches

Trigeminal autonomic cephalgias
Paroxysmal hemicranias
Chronic paroxysmal hemicrania
Episodic paroxysmal hemicrania
Hemicrania continua
Valsalva-induced headaches
Primary cough headache
Primary exertional headache
Primary headache associated with sexual activity (preorgasmic and orgasmic)
Primary stabbing headache (jabs and jolts syndrome)
Hypnic headacheOthers

Patent ductus arteriosus

Contraindications
Concurrent peptic ulcer, or history of ulcer disease
Allergy to indometacin, aspirin, or other NSAIDs
Roux-en-Y gastric bypass and gastric sleeve patients
Patients with nasal polyps reacting with an angioedema to other NSAIDs
Children under 2 years of age (with the exception of neonates with patent ductus arteriosus)
Severe pre-existing renal and liver damage
Caution: pre-existing bone marrow damage (frequent blood cell counts are indicated)
Caution: bleeding tendencies of unknown origin (indometacin inhibits platelet aggregation)
Caution: Parkinsons disease, epilepsy, psychotic disorders (indometacin may worsen these conditions)
Concurrent with potassium sparing diuretics
Patients who have a patent ductus arteriosus dependent heart defect (such as transposition of the great vessels)
Significant hypertension (high blood pressure)
Concomitant administration of lithium salts (such as lithium carbonate)

Adverse effects
In general, adverse effects seen with indometacin are similar to all other NSAIDs. For instance,  indometacin inhibits both cyclooxygenase-1 and cyclooxygenase-2, which then inhibits the production of prostaglandins in the stomach and intestines responsible for maintaining the mucous lining of the gastrointestinal tract. Indometacin, therefore, like other non-selective COX inhibitors, can cause peptic ulcers. These ulcers can result in serious bleeding or perforation, requiring hospitalization of the patient. To reduce the possibility of peptic ulcers, indometacin should be prescribed at the lowest dosage needed to achieve a therapeutic effect, usually between 50 and 200 mg/day. It should always be taken with food.
Indometacin, also known as indomethacin, is a nonsteroidal anti-inflammatory drug (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation. It works by inhibiting the production of prostaglandins, endogenous signaling molecules known to cause these symptoms. It does this by inhibiting cyclooxygenase, an enzyme that catalyzes the production of prostaglandins.It was patented in 1961 and approved for medical use in 1963. It is on the World Health Organizations List of Essential Medicines. It is marketed under more than twelve different trade names. In 2017, it was the 291st most commonly prescribed medication in the United States, with more than one million prescriptions. Medical uses
As an NSAID, indometacin is an analgesic, anti-inflammatory, and antipyretic.