betamethasone

Action

Stabilizes lysosomal neutrophils and prevents their degranulation, inhibits synthesis of lipoxygenase products and prostaglandins, activates anti-inflammatory genes, and inhibits various cytokines

Availability

Solution for injection: 3 mg betamethasone sodium phosphate with 3 mg betamethasone acetate/ml

Suspension for injection (acetate, phosphate): 6 mg (total)/ml

Syrup: 0.6 mg/5 ml

Tablets: 0.6 mg

Tablets (effervescent): 0.5 mg

Tablets (extended-release): 1 mg

Indications and dosages

➣ Inflammatory, allergic, hematologic, neoplastic, autoimmune, and respiratory diseases; prevention of organ rejection after transplantation surgery

Adults: 0.6 to 7.2 mg/day P.O. as single daily dose or in divided doses; or up to 9 mg I.M. of betamethasone acetate and sodium phosphate suspension.

➣ Bursitis or tenosynovitis

Adults: 1 ml of suspension intrabursally

➣ Rheumatoid arthritis or osteoarthritis

Adults: 0.5 to 2 ml of suspension intra-articularly

Off-label uses

• Respiratory distress syndrome

Contraindications

• Hypersensitivity to drug

• Breastfeeding

Precautions

Use cautiously in:

• systemic infections, hypertension, osteoporosis, diabetes mellitus, glaucoma, renal disease, hypothyroidism, cirrhosis, diverticulitis, thromboembolic disorders, seizures, myasthenia gravis, heart failure, ocular herpes simplex, emotional instability

• patients receiving systemic corticosteroids

• pregnant patients

• children younger than age 6.

Administration

• Give as a single daily dose before 9:00 A.M.

• Give oral dose with food or milk.

• Administer I.M. injection deep into gluteal muscle (may cause tissue atrophy).

☞ Don't give betamethasone acetate I.V.

• Be aware that typical suspension dosage ranges from one-third to one-half of oral dosage given q 12 hours.

☞ To avoid adrenal insufficiency, taper dosage slowly and under close supervision when discontinuing.

• Know that drug may be given with other immunosuppressants.

Adverse reactions

CNS: headache, nervousness, depression, euphoria, psychoses, increased intracranial pressure

CV: hypertension, thrombophlebitis, thromboembolism

EENT: cataracts, burning and dryness of eyes, rebound nasal congestion, sneezing, epistaxis, nasal septum perforation, difficulty speaking, oropharyngeal or nasopharyngeal fungal infections

GI: nausea, vomiting, anorexia, dry mouth, esophageal candidiasis, peptic ulcers

Metabolic: decreased growth, hyperglycemia, cushingoid appearance, adrenal insufficiency or suppression

Musculoskeletal: muscle wasting, muscle pain, osteoporosis, aseptic joint necrosis

Respiratory: cough, wheezing, bronchospasm

Skin: facial edema, rash, contact dermatitis, acne, ecchymosis, hirsutism, petechiae, urticaria, angioedema

Other: loss of taste, bad taste, weight gain or loss, Churg-Strauss syndrome, increased susceptibility to infection, hypersensitivity reaction

Interactions

Drug-drug. Amphotericin B, loop and thiazide diuretics, ticarcillin: additive hypokalemia

Barbiturates, phenytoin, rifampin: stimulation of betamethasone metabolism, causing decreased drug effects

Digoxin: increased risk of digoxin toxicity

Fluoroquinolones (such as ciprofloxacin, norfloxacin): increased risk of tendon rupture

Hormonal contraceptives: blockage of betamethasone metabolism

Insulin, oral hypoglycemics: increased betamethasone dosage requirement, diminished hypoglycemic effects

Live-virus vaccines: decreased antibody response to vaccine, increased risk of neurologic complications

Nonsteroidal anti-inflammatory drugs: increased risk of adverse GI effects

Drug-diagnostic tests. Calcium, potassium: decreased levels

Cholesterol, glucose: increased levels

Nitroblue tetrazolium test for bacterial

infection: false-negative result

Drug-herbs. Echinacea: increased immune-stimulating effects

Ginseng: increased immune-modulating effects

Drug-behaviors. Alcohol use: increased risk of gastric irritation and GI ulcers

Patient monitoring

• Monitor weight daily and report sudden increase, which suggests fluid retention.

• Monitor blood glucose level for hyperglycemia.

• Assess serum electrolyte levels for sodium and potassium imbalances.

• Watch for signs and symptoms of infection (which drug may mask).

Patient teaching

• Advise patient to report signs and symptoms of infection.

• Tell patient to report visual disturbances (long-term drug use may cause cataracts).

• Instruct patient to eat low-sodium, high potassium diet.

☞ Advise patient to carry medical identification describing drug therapy.

• Inform female patients that drug may cause menstrual irregularities.

☞ Caution patient not to stop taking drug abruptly.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.