PIROXICAM

PIROXICAM (peer-ox'i-kam) Feldene Classifications: analgesic, nonsteroidal antiinflammatory drug (nsaid); antipyretic; Therapeutic: nsaid, analgesic; antipyretic Prototype: Ibuprofen Pregnancy Category: C

Availability

10 mg, 20 mg capsules

Action

Nonsteroidal antiinflammatory agent. Strongly inhibits enzyme cyclooxygenase, both COX1 and COX2, the catalyst of prostaglandin synthesis. Decreased prostaglandin is responsible for its anti-inflammatory properties, analgesic and antipyretic effects.

Therapeutic Effect

Drug-induced reduction in prostaglandin levels is associated with decreased inflammatory processes in bone-joint disease, as well as analgesic and antipyretic effects.

Uses

Acute and long-term relief of mild to moderate pain and for symptomatic treatment of osteoarthritis and rheumatoid arthritis.

Unlabeled Uses

Acute and chronic relief of mild to moderate pain.

Contraindications

Hypersensitivity to NSAIDs or salicylates; hemophilia; active peptic ulcer, GI bleeding; CABG perioperative pain; pregnancy (category C). Safety in children is not established.

Cautious Use

History of upper GI disease including ulcerative colitis; SLE; kidney dysfunction; CHF; compromised cardiac function; hypertension or other conditions predisposing to fluid retention; renal disease; coagulation disorders.

Route & Dosage

Arthritis, Pain Adult: PO 10–20 mg 1–2 times/d

Administration

Oral

• Give at the same time every day.
• Give capsule with food or fluid to help reduce GI irritation.
• Give older adults (>70 y) ? of the usual adult dose.
• Make dose adjustments on basis of clinical response at intervals of weeks rather than days in order to prevent over dosage.
• Store in tightly closed container at 15°–30° C (59°–86° F) unless otherwise directed.

Adverse Effects (≥1%)

CNS: Somnolence, dizziness, vertigo, depression, insomnia, nervousness. CV: Peripheral edema, hypertension, worsening of CHF, exacerbation of angina. Special Senses: Tinnitus, hearing loss, blurred vision, reduced visual acuity, changes in color vision, scotomas, corneal deposits, retinal disturbances. GI: Nausea, vomiting, dyspepsia, GI bleeding, diarrhea, constipation, flatulence, dry mouth, peptic ulceration, anorexia, jaundice, hepatitis. Hematologic: Anemia, decreases in Hgb, Hct; leukopenia, eosinophilia, aplastic anemia; thrombocytopenia, prolonged bleeding time. Skin: Urticaria, erythema multiforme, maculopapular, vesiculobullous rash; photosensitivity, sweating, Stevens-Johnson syndrome, bruising, dermatitis. Body as a Whole: Allergic rhinitis, angioedema, fever, palpitations, syncope, muscle cramps, fever, hypersensitivity reactions. Metabolic: Hypoglycemia, hyperglycemia, hyperkalemia, weight gain. Urogenital: Dysuria, acute kidney failure, papillary necrosis, hematuria, proteinuria, nephrotic syndrome. Respiratory: Bronchospasm, dyspnea.

Interactions

Drug: oral anticoagulants, heparin may prolong bleeding time; may increase lithium toxicity; alcohol, aspirin increase risk of GI hemorrhage. Herbal: Feverfew, garlic, ginger, ginkgo may increase bleeding potential.

Pharmacokinetics

Absorption: Extenstively from GI tract. Onset: 1 h analgesia; 7 d for rheumatoid arthritis. Peak: 3–5 h analgesia; 2–4 wk antirheumatic. Duration: 48–72 h analgesia. Distribution: Small amount distributed into breast milk. Metabolism: Extensively in liver. Elimination: Primarily in urine, some in bile (<5%). Half-Life: 30–86 h.

Nursing Implications

Assessment & Drug Effects

• Wait at least 7 d to evaluate antirheumatic effect.
• Clinical evidence of benefits from drug therapy include pain relief in motion and in rest, reduction in night pain, stiffness, and swelling; increased ROM (range of motion) in all joints.
• Be aware that adverse effects may not appear for 7–10 d after start of therapy (except for an allergic reaction).
• Lab tests: Periodic BUN, ALT, AST, CBC, Hgb and Hct in patient (especially the older adult) receiving drug for an extended period.

Patient & Family Education

• If a dose is missed, take drug when missed dose is discovered if it is 6–8 h before the next scheduled dose. Otherwise, omit dose and reestablish regimen at next scheduled hour.
• Do not self-dose with aspirin or other OTC drug without physician's advice.
• Do not increase dosage beyond prescribed regimen. Understand that long half-life of drug may cause delayed therapeutic effect. Higher than recommended doses are associated with increased incidence of GI irritation and peptic ulcer.
• Incidence of GI bleeding with this drug is relatively high. Report symptoms of GI bleeding (e.g., dark, tarry stools, coffee-colored emesis) or severe gastric pain promptly to physician.
• Be alert to symptoms of drug-induced anemia: Profound fatigue, skin and mucous membrane pallor, lethargy.
• Avoid alcohol since it may increase the risk of GI bleeding.
• Be alert to signs of hypoprothrombinemia including bruises, pinpoint rash, unexplained bleeding, nose bleed, blood in urine, when piroxicam is taken concomitantly with an anticoagulant.
• Do not drive or engage in potentially hazardous activities until response to drug is known.
• Drink at least 6–8 full glasses of water daily and report signs of renal insufficiency (see Appendix F) to physician because most of drug is excreted by kidneys and impaired kidney function increases danger of toxicity.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug