PIROXICAM
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis, thereby decreasing inflammation, pain, and fever.
| Metabolism | Primarily hepatic via cytochrome P450 (CYP) 2C9, with minor contributions from CYP2C8 and CYP3A4; undergoes oxidative metabolism to inactive metabolites. |
| Excretion | Approximately 60-70% renal (glomerular filtration and tubular secretion) as unchanged drug and metabolites; 30-40% fecal via biliary excretion. Less than 5% as unchanged drug in urine. |
| Half-life | Terminal elimination half-life is 50 hours (range 30-86 hours), allowing once-daily dosing. Prolonged in elderly (up to 80 hours) and in hepatic impairment. |
| Protein binding | 99% bound to albumin. The high binding limits distribution and reduces free fraction. |
| Volume of Distribution | 0.14-0.17 L/kg (14-17 L in 70 kg adult). Small Vd indicates limited extravascular distribution, consistent with high protein binding. |
| Bioavailability | Oral: 100% (well absorbed). Topical: 0.5-2% systemic absorption. Intramuscular: 100%. |
| Onset of Action | Oral: 30-60 minutes for analgesic effect; therapeutic effect in rheumatoid arthritis within 1 week. Intramuscular: 15-30 minutes. Topical: 2-4 hours for local effect. |
| Duration of Action | 24 hours for analgesic effect due to long half-life; sufficient for once-daily dosing. Steady state reached in 7-12 days. |
10-20 mg orally once daily; maximum 20 mg/day.
| Dosage form | CAPSULE |
| Renal impairment | No adjustment required for mild to moderate impairment (GFR ≥30 mL/min). Avoid use in severe impairment (GFR <30 mL/min) due to increased risk of nephrotoxicity. |
| Liver impairment | Mild to moderate hepatic impairment (Child-Pugh A or B): use with caution; consider reducing dose by 50%. Severe (Child-Pugh C): contraindicated. |
| Pediatric use | Not recommended for children under 18 years of age due to lack of safety and efficacy data. |
| Geriatric use | Initiate at lowest effective dose (10 mg once daily); monitor renal function and gastrointestinal tolerance closely; do not exceed 15 mg/day. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
ACE inhibitors and ARBs may have diminished antihypertensive effect Increases risk of serious cardiovascular thrombotic events and GI bleeding.
| Breastfeeding | Piroxicam is excreted into breast milk in small amounts. The milk-to-plasma ratio is approximately 0.01-0.03. Due to limited data, avoid use in breastfeeding women, especially with prolonged therapy. |
| Teratogenic Risk | Piroxicam is contraindicated in the third trimester due to risk of premature closure of the ductus arteriosus and oligohydramnios. In the first and second trimesters, there is a potential increased risk of miscarriage and cardiac malformations; use only if clearly needed. |
■ FDA Black Box Warning
NSAIDs cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. Piroxicam is contraindicated for treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
| Common Effects | No common side effects seen Vomiting Stomach pain Nausea Headache Dizziness |
| Serious Effects |
Hypersensitivity to piroxicam or any NSAID, history of asthma/urticaria after aspirin/NSAID use, perioperative pain in CABG surgery, active gastrointestinal bleeding, history of peptic ulcer disease, severe renal impairment (eGFR <30 mL/min), hepatic failure, third trimester of pregnancy, and nursing mothers (due to potential adverse effects in infant).
| Precautions | Cardiovascular risk (thrombotic events, hypertension, fluid retention), gastrointestinal risk (bleeding, ulceration, perforation), renal toxicity, hepatic impairment, anaphylactoid reactions, serious skin reactions (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis), hematologic effects (anemia, platelet inhibition), masking of infection, use in pregnancy (avoid in third trimester due to premature closure of ductus arteriosus), and caution in elderly and patients with prior GI disease. |
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| Fetal Monitoring |
| Monitor for signs of ductus arteriosus constriction (fetal echocardiography), oligohydramnios (amniotic fluid index), and maternal renal function. In neonates, monitor for bleeding tendencies and persistent pulmonary hypertension. |
| Fertility Effects | Reversible inhibition of ovulation and implantation due to prostaglandin synthesis inhibition; may delay or impair fertility. Effects are reversible upon discontinuation. |