Use caution with a history of GI disease (bleeding or ulcers), concurrent therapy with aspirin, anticoagulants and/or corticosteroids, smoking, use of alcohol, the elderly or debilitated patients. Use the lowest effective dose for the shortest duration of time, consistent with individual patient goals, to reduce risk of GI adverse events; alternate therapies should be considered for patients at high risk. When used concomitantly with ≤325 mg of aspirin, a substantial increase in the risk of gastrointestinal complications (e.g., ulcer) occurs; concomitant gastroprotective therapy (e.g., proton pump inhibitors) is recommended. The increased risk is about 81%. Hematologic effects: Anemia may occur; monitor hemoglobin or hematocrit in people on long-term treatment. Celecoxib does not usually affect prothrombin time, partial thromboplastin time or platelet counts; it does not inhibit platelet aggregation at approved doses.People with prior history of ulcer disease or GI bleeding require special precaution. Moderate to severe liver impairment or GI toxicity can occur with or without warning symptoms in people treated with NSAIDs. In October 2020, the U.S. Food and Drug Administration (FDA) required the drug label to be updated for all nonsteroidal anti-inflammatory medications to describe the risk of kidney problems in unborn babies that result in low amniotic fluid. They recommend avoiding NSAIDs in pregnant women at 20 weeks or later in pregnancy. Allergy
Celecoxib contains a sulfonamide moiety and may cause allergic reactions in those allergic to other sulfonamide-containing drugs. This is in addition to the contraindication in people with severe allergies to other NSAIDs.
The presence of deviant bands on IEF can signify the presence of alpha-1 antitrypsin deficiency. Since the number of identified mutations has exceeded the number of letters in the alphabet, subscripts have been added to most recent discoveries in this area, as in the Pittsburgh mutation described above. As every person has two copies of the A1AT gene, a heterozygote with two different copies of the gene may have two different bands showing on electrofocusing, although a heterozygote with one null mutant that abolishes expression of the gene will only show one band. In blood test results, the IEF results are notated as, e.g., PiMM, where Pi stands for protease inhibitor and "MM" is the banding pattern of that person.Other detection methods include use of enzyme-linked-immuno-sorbent-assays in vitro and radial immunodiffusion. Alpha-1 antitrypsin levels in the blood depend on the genotype. Some mutant forms fail to fold properly and are, thus, targeted for destruction in the proteasome, whereas others have a tendency to polymerize, thereafter being retained in the endoplasmic reticulum. The serum levels of some of the common genotypes are:
PiMM: 100% (normal)
PiMS: 80% of normal serum level of A1AT
PiSS: 60% of normal serum level of A1AT
PiMZ: 60% of normal serum level of A1AT
PiSZ: 40% of normal serum level of A1AT
PiZZ: 10–15% (severe alpha-1 antitrypsin deficiency)

Treatment
Treatment of lung disease may include bronchodilators, inhaled steroids, and, when infections occur, antibiotics. Intravenous infusions of the A1AT protein or in severe disease lung transplantation may also be recommended.