Betamethasone

[[Category:Immunosuppression agent, Immunosuppression agent,

Steroid replacement agent ]]

=Introduction

Betamethasone is a steroid with anti-inflammatory and immunosuppressant effects. It is used to treat a wide range of inflammatory and autoimmune conditions.

Indications include:

• Inflammatory bowel disease
• Asthma
• Croup in children
• dermatitis
• Rheumatoid arthritis

Equivalent anti-inflammatory doses of steroids

Prednisolone 5 mg is equivalent to	Betamethasone 750 micrograms
	dexamethasone 750 micrograms
	hydrocortisone 20 mg
	methylprednisolone 4 mg
	triamcinolone 4 mg

Betamethasone is available as various compounds: Betamethasone diproprionate (branded as Diprosone) Betamethasone sodium phosphate Betamethasone valerate (Branded as Betnovate)

Mechanism of Action

Immunosuppression agent Steroid replacement agent Anti-inflammatory agent

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Betamethasone (valerate) cream 0.1% 15g	BETA13	P1S1S3
Betamethasone (valerate) ointment 0.1% 15g	BETA09	P1S1S3
Betamethasone (valerate) Scalp Application 0.1% 30ml	BETA06	P1S1S3

Dosage

Dosages of steroids vary widely in different diseases and in different patients. When long-term steroid therapy is used in some chronic diseases, the adverse effects of treatment may be great. To minimize side-effects the maintenance dose should be kept as low as possible. Steroids are used both topically (by rectum or eye) and systemically (by mouth or intravenously). Whenever possible local treatment with creams, intra-articular injections, inhalations, eye-drops or enemas should be used in preference to systemic treatment. The suppressive action of a steroid on cortisol secretion is least when it is given as a single dose in the morning.

Oral: usual range 0.5 – 5 mg daily

By intramuscular injection or slow intravenous injection: 4 – 20 mg, repeated up to 4 times in 24 hours

Child dosage: slow intravenous injection:

• Infants aged up to 1 year: 1mg
• 1-5 years: 2 mg
• 6 to 12 years: 4 mg
• 12 years and older: adult doses

Doses repeated up to 4 times in 24 hours according to response

Side Effects

Short-term use include nausea and feeling tired. More severe side effects include psychiatric problems including euphoria, nightmares, insomnia, irritability, confusion, suicidal thoughts and behavioral disturbances. This may occur in about 5% of people.

Long-term steroid use can lead to:

Adrenal suppression
Steroid-induced diabetes
Osteoporosis, muscle wasting and weakness	which is a danger, particularly in the elderly, as it can result in osteoporotic fractures for example of the hip or vertebrae
Onset of action	Peak plasma levels in about one hour after ingestion. Absorption from transdermal patches is slow and peak plasma concentrations are reached in 10 to 16 hours after applying the first patch; with subsequent patches, peak concentrations are reached in about 8 hours.
Metabolism	Primarily metabolized through hydrolysis. Minimal metabolism occurs via the cytochrome P450.
Elimination half-life	1.5 hours after oral doses and about 3 hours after patch removal.