betamethasone

Pregnancy Category C

Drug classes

Corticosteroid (long acting)

Glucocorticoid

Hormonal agent

Therapeutic actions

Binds to intracellular corticosteroid receptors, thereby initiating many natural complex reactions that are responsible for its anti-inflammatory and immunosuppressive effects.

Indications

Systemic administration

· Hypercalcemia associated with cancer

· Short-term management of inflammatory and allergic disorders, such as rheumatoid arthritis, collagen diseases (eg SLE), dermatologic diseases (eg pemphigus), status asthmaticus, and autoimmune disorders

· Hematologic disorders: Thrombocytopenia purpura, erythroblastopenia

· Ulcerative colitis, acute exacerbations of multiple sclerosis, and palliation in some leukemias and lymphomas

· Trichinosis with neurologic or myocardial involvement

· Unlabeled use: Prevention of respiratory distress syndrome in premature neonates

Intra-articular or soft-tissue administration

· Arthritis, psoriatic plaques, and so forth

Dermatologic preparations

· Relief of inflammatory and pruritic manifestations of steroid-responsive dermatoses

Contraindications and cautions

Systemic (oral and parenteral) administration

· Contraindicated with infections, especially tuberculosis, fungal infections, amebiasis, vaccinia and varicella, and antibiotic-resistant infections, lactation.

All forms

· Use cautiously with kidney or liver disease, hypothyroidism, ulcerative colitis with impending perforation, diverticulitis, active or latent peptic ulcer, inflammatory bowel disease, CHF, hypertension, thromboembolic disorders, osteoporosis, seizure disorders, diabetes mellitus.

Available forms

Tablets—0.6 mg; syrup—0.6 mg/5 mL; injection—4 mg, 3 mg betamethasone sodium phosphate with 3 mg betamethasone acetate; ointment—0.1%, 0.05%; cream—0.01%, 0.05%, 0.1%; lotion—0.1%, 0.05%; gel—0.05%

Dosages

ADULTS

Systemic administration

Individualize dosage, based on severity and response. Give daily dose before 9 AM to minimize adrenal suppression. Reduce initial dose in small increments until the lowest dose that maintains satisfactory clinical response is reached. If long-term therapy is needed, alternate-day therapy with a short-acting corticosteroid should be considered. After long-term therapy, withdraw drug slowly to prevent adrenal insufficiency.

· Oral (betamethasone): Initial dosage, 0.6–7.2 mg/day

· IV (betamethasone sodium phosphate): Initial dosage, up to 9 mg/day.

· IM (betamethasone sodium phosphate; betamethasone sodium phosphate and acetate): Initial dosage, 0.5–9 mg/day. Dosage range is one-third to one-half oral dose given q 12 hr. In life-threatening situations, dose can be in multiples of the oral dose.

Intrabursal, intra-articular, intradermal, intralesional (betamethasone sodium phosphate and acetate)

0.25–2 mL intra-articular, depending on joint size; 0.2 mL/cm³ intradermally, not to exceed 1 mL/wk; 0.25–1 mL at 3- to 7-day intervals for disorders of the foot.

Topical dermatologic cream, ointment (betamethasone dipropionate)

Apply sparingly to affected area bid–qid.

PEDIATRIC PATIENTS

Systemic administration

Individualize dosage on the basis of severity and response rather than by formulae that correct adult doses for age or weight. Carefully observe growth and development in infants and children on prolonged therapy.

Pharmacokinetics

Route	Onset	Duration
Systemic	Varies	3 days

Metabolism: Hepatic; T_1/2: 36–54 hr

Distribution: Crosses placenta; enters breast milk

Excretion: Unchanged in the urine

IV facts

Preparation: No further preparation needed.

Infusion: Infuse by direct IV injection over 1 min or into the tubing of running IV of dextrose or saline solutions.

Adverse effects

· CNS: Vertigo, headache, paresthesias, insomnia, seizures, psychosis, cataracts, increased IOP, glaucoma (in long-term therapy)

· CV: Hypotension, shock, hypertension, and CHF secondary to fluid retention, thromboembolism, thrombophlebitis, fat embolism, cardiac arrhythmias

· Electrolyte imbalance: Na⁺ and fluid retention, hypokalemia, hypocalcemia

· Endocrine: Amenorrhea, irregular menses, growth retardation, decreased carbohydrate tolerance, diabetes mellitus, cushingoid state (long-term effect), increased blood sugar, increased serum cholesterol, decreased T₃ and T₄ levels, hypothalamic-pituitary-adrenal (HPA) suppression with systemic therapy longer than 5 days

· GI: Peptic or esophageal ulcer, pancreatitis, abdominal distention, nausea, vomiting, increased appetite, weight gain (long-term therapy)

· Musculoskeletal: Muscle weakness, steroid myopathy, loss of muscle mass, osteoporosis, spontaneous fractures (long-term therapy)

· Other: Immunosuppression, aggravation, or masking of infections; impaired wound healing; thin, fragile skin; petechiae, ecchymoses, purpura, striae; subcutaneous fat atrophy; hypersensitivity or anaphylactoid reactions

The following effects are related to various local routes of steroid administration:

· Intra-articular: Osteonecrosis, tendon rupture, infection

· Intralesional therapy: Blindness when applied to face and head

· Topical dermatologic ointments, creams, sprays: Local burning, irritation, acneiform lesions, striae, skin atrophy

Interactions

Drug-drug

· Risk of severe deterioration of muscle strength in myasthenia gravis patients receiving ambenonium, edrophonium, neostigmine, pyridostigmine

· Decreased steroid blood levels with barbiturates, phenytoin, rifampin

· Decreased effectiveness of salicylates with betamethasone

Drug-lab test

· False-negative nitroblue-tetrazolium test for bacterial infection

· Suppression of skin test reactions

Nursing considerations

Assessment

· History (systemic administration): Infections, fungal infections, amebiasis, vaccinia and varicella, and antibiotic-resistant infections; kidney or liver disease; hypothyroidism; ulcerative colitis with impending perforation; diverticulitis; active or latent peptic ulcer; inflammatory bowel disease; CHF; hypertension; thromboembolic disorders; osteoporosis; seizure disorders; diabetes mellitus; lactation

· Physical: Baseline weight, T, reflexes and grip strength, affect and orientation, P, BP, peripheral perfusion, prominence of superficial veins, R and adventitious sounds, serum electrolytes, blood glucose

Interventions

Systemic use

· Give daily dose before 9 AM to mimic normal peak corticosteroid blood levels.

· Increase dosage when patient is subject to stress.

· Taper doses when discontinuing high-dose or long-term therapy.

· Do not give live virus vaccines with immunosuppressive doses of corticosteroids.

Topical dermatologic preparations

· Examine area for infections, skin integrity before application.

· Administer cautiously to pregnant patients; topical corticosteroids have caused teratogenic effects and can be absorbed from systemic site.

· WARNING: Use caution when occlusive dressings or tight diapers cover affected area; these can increase systemic absorption of the drug.

· Avoid prolonged use near eyes, in genital and rectal areas, and in skin creases.

Teaching points

Systemic use

· Do not stop taking the oral drug without consulting your health care provider.

· Take single dose or alternate-day doses before 9 AM.

· Avoid exposure to infections; ability to fight infections is reduced.

· Wear a medical alert tag so emergency care providers will know that you are on this medication.

· You may experience these side effects: Increase in appetite, weight gain (counting calories may help); heartburn, indigestion (eat frequent small meals; take antacids); poor wound healing (consult with your care provider); muscle weakness, fatigue (frequent rest periods will help).

· Report unusual weight gain, swelling of the extremities, muscle weakness, black or tarry stools, fever, prolonged sore throat, colds or other infections, worsening of original disorder.

Intrabursal, intra-articular therapy

· Do not overuse joint after therapy, even if pain is gone.

Topical dermatologic preparations

· Apply sparingly; do not cover with tight dressings.

· Avoid contact with the eyes.

· Report irritation or infection at the site of application.

Adverse effects in Italic are most common; those in Bold are life-threatening.