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. |
| Molecular Weight | 331.35 |
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 | Avoid unless potential benefit outweighs risk. Associated with increased risk of spontaneous abortion and congenital malformations (e.g., cardiovascular). NSAIDs should be used at the lowest effective dose for the shortest duration possible. |
| 2nd trimester | Use with caution. May cause oligohydramnios and fetal renal dysfunction. Monitor amniotic fluid volume if prolonged use. |
| 3rd trimester | Contraindicated after 30 weeks gestation due to risk of premature closure of ductus arteriosus and persistent pulmonary hypertension of the newborn. Avoid use. |
Clinical note
ACE inhibitors and ARBs may have diminished antihypertensive effect Increases risk of serious cardiovascular thrombotic events and GI bleeding.
| Placental transfer | Crosses the placenta; drug levels in fetal plasma are approximately 40-50% of maternal levels based on limited data. |
| Breastfeeding | Excreted into breast milk in low amounts (relative infant dose <10%). Considered compatible with breastfeeding by the American Academy of Pediatrics, but caution in cases of infant thrombocytopenia or hypersensitivity. Monitor infant for gastrointestinal bleeding or drowsiness. |
■ 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 |
History of allergic-type reactions to aspirin or other NSAIDs (including asthma, urticaria, or other allergic reactions)Active peptic ulcer disease or gastrointestinal bleedingSevere uncontrolled heart failureHistory of coronary artery bypass graft (CABG) surgery within the past 14 daysThird trimester of pregnancy (after 30 weeks gestation)
| 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. |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| 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. |
| 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. |
| Food/Dietary | Take with food or milk to minimize GI irritation. Avoid alcohol concurrently due to increased GI bleeding risk. Avoid high-potassium foods if on ACE inhibitors or potassium-sparing diuretics due to risk of hyperkalemia. |
| Clinical Pearls | Piroxicam has a long half-life (50 hours) allowing once-daily dosing, but accumulation risk in elderly or renal impairment. Use lowest effective dose; increased GI bleeding risk with NSAIDs, especially in elderly. Consider misoprostol or PPI for high-risk patients. Inhibits platelet aggregation reversibly but prolonged effect due to long half-life; discontinue 5 half-lives (10 days) before surgery if antiplatelet effect not desired. Monitor renal function and blood pressure; may reduce antihypertensive efficacy of ACE inhibitors and diuretics. |
| Patient Advice | Take with food or milk to reduce stomach upset. · Avoid alcohol; it increases risk of stomach bleeding. · Watch for signs of GI bleeding: black/tarry stools, vomit with blood or coffee-ground appearance. · Do not take other NSAIDs or aspirin while on piroxicam. · Report any unexplained weight gain, swelling, or shortness of breath. · May cause dizziness or drowsiness; avoid driving if affected. · Sun sensitivity: use sunscreen, wear protective clothing; avoid tanning beds. · Do not exceed prescribed dose; long-term use requires periodic monitoring. |