DICLOFENAC SODIUM

DICLOFENAC SODIUM
(di-klo'fen-ak)
Voltaren, Voltaren-XR, Solaraze
DICLOFENAC POTASSIUM
Cataflam
Classifications: analgesic, nonsteroidal antiinflammatory drug (nsaid); antipyretic;
Therapeutic: nsaid, analgesic; antipyretic
Prototype: Ibuprofen
Pregnancy Category: B

Availability

Diclofenac Sodium: 25 mg, 50 mg, 75 mg tablets; 100 mg sustained release tablets; 0.1% ophthalmic solution; 3% gel

Diclofenac Potassium: 50 mg tablets

Action

Diclofenac competitively inhibits both cyclooxygenase (COX) isoenzymes, COX-1 and COX-2, by blocking arachidonic acid conversion to other chemicals, thus leading to its analgesic, antipyretic, and antiinflammatory pharmacologic effects. It appears to be a potent inhibitor of cyclooxygenase, thereby decreasing the synthesis of prostaglandins.

Therapeutic Effect

Nonsteroidal antiinflammatory drug (NSAID) with analgesic and antipyretic activity.

Uses

Analgesic and antipyretic effects in symptomatic treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. Also acute gout; juvenile rheumatoid arthritis; various rheumatic conditions including bursitis, myalgia, sciatica, and tendinitis; acute soft tissue injuries including sprains and strains; dysmenorrhea; headache, migraine, and dental, minor surgical, and postpartum pain; and renal or biliary colic. Ophthalmic: Cataract surgery; photophobia associated with refractive surgery. Topical: Treatment of actinic keratosis.

Contraindications

Hypersensitivity to diclofenac, NSAIDS, or salicylate; patients in whom asthma, urticaria, angioedema, bronchospasm, severe rhinitis, history of GI bleeding; hepatic porphyria; shock, or other sensitivity reaction is precipitated by aspirin or other NSAIDS; postoperative CABG pain.

Cautious Use

Geriatric patients and children; patients receiving anticoagulant therapy; diabetes mellitus; history of GI disease; hepatic disease; GU tract problems such as dysuria, cystitis, hematuria, nephritis, nephrotic syndrome, patients who must restrict their sodium intake; impaired hepatic function; SLE; heart failure, cardiac disease; hypertension; pregnancy (category B), lactation.

Route & Dosage

Rheumatoid Arthritis
Adult: PO 150–200 mg/d in 3–4 divided doses
Child: PO 25 mg b.i.d. or t.i.d.

Osteoarthritis
Adult: PO 100–150 mg/d in 3–4 divided doses 100 mg sustained release q.d.

Ankylosing Spondylitis
Adult: PO 25 mg q.i.d. and 25 mg h.s.

Cataract Surgery
Adult: Ophthalmic 1 drop of 0.1% solution in affected eye q.i.d. beginning 24 h after surgery and continuing for 2 wk

Actinic Keratosis
Adult: Topical Apply to affected area b.i.d. for 60–90 d

Administration

Oral

Ensure that sustained release or enteric coated forms of drug are not chewed or crushed. MUST be swallowed whole.
Give on an empty stomach, 1 h before or after a meal; absorption is delayed markedly by food. Minimize gastric irritation by administering it with a full glass of milk or water.
Schedule administration 30 min before physical therapy or planned exercise to keep discomfort at a minimum.
Discontinue therapy about 1 wk before surgery to reduce risk of bleeding.
Use with caution in anyone who must restrict sodium intake.
Store at 15°–30° C (59°–86° F) away from heat and direct light.

Adverse Effects (≥1%)

CNS: Dizziness, headache, drowsiness. Special Senses: Tinnitus. Skin: Rash, pruritus. GI: Dyspepsia, nausea, vomiting, abdominal pain, cramps, constipation, diarrhea, indigestion, abdominal distension, flatulence, peptic ulcer; liver enzymes, transaminases increased, liver test abnormalities. CV: Fluid retention, hypertension, CHF. Respiratory: Asthma. Body as a Whole: Back, leg, or joint pain. Endocrine: Hyperglycemia. Hematologic: Prolonged bleeding time; inhibits platelet aggregation.

Diagnostic Test Interference

Liver function test values may be increased. Liver function test abnormalities may return to normal despite continued use; however, if significant abnormalities occur, clinical signs and symptoms consistent with liver disease develop, or systemic manifestations such as eosinophilia or rash occur, the medication should be discontinued. Serum uric acid concentrations may be decreased because of increased renal clearance.

Interactions

Drug: Increases cyclosporine-induced nephrotoxicity; increases methotrexate levels (increases toxicity); may decrease BP-lowering effects of diuretics; may increase levels and toxicity of lithium; may increase digoxin levels. Herbal: Feverfew, garlic, ginger, ginkgo may increase risk of bleeding.

Pharmacokinetics

Absorption: Readily absorbed from GI tract; 50–60% reaches systemic circulation. Peak: 2–3 h. Distribution: Widely distributed including synovial fluid and into breast milk. Metabolism: Extensively metabolized in liver. Elimination: 50–70% in urine, 30–35% in feces. Half-Life: 1.2–2 h.

Nursing Implications

Assessment & Drug Effects

Monitor for therapeutic effectiveness. Up to 3 wk may be needed for beneficial effects with rheumatoid arthritis or osteoarthritis.
Lab tests: Periodic liver function, serum uric acid concentrations Hct, PT/INR, and blood glucose.
Observe and report signs of bleeding (e.g., petechiae, ecchymoses, bleeding gums, bloody or black stools, cloudy or bloody urine).
Monitor BP for hypertension and blood sugar for hyperglycemia.
Monitor diabetics closely for loss of diabetic control.
Monitor for increased serum sodium and potassium in patients receiving potassium-sparing diuretics.
Monitor weight and report gains greater than 1 kg (2 lb)/24 h.
Monitor for signs and symptoms of GI irritation and ulceration.

Patient & Family Education

Oral Form

Do not lie down for 15–30 min after taking medicine to decrease esophageal irritation.
Discontinue use with onset of ringing or buzzing in the ears, impaired hearing, dizziness, GI discomfort, or bleeding and notify physician.
Do not take aspirin or other OTC analgesics without permission of the physician.
Avoid alcohol or other CNS depressants.
Do not drive or engage in other potentially hazardous activities until reaction to drug is known.
Note: Diabetics need to monitor blood glucose carefully for loss of glycemic control.

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

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