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 |
| Susceptibility to infection | |
| Cushing’s syndrome | moon face, striae, and acne |
| Endocrine side effects | menstrual irregularities and amenorrhea, hirsutism, weight gain, hyperlipidemia |
| Neuropsychiatric side effects | aggravation of schizophrenia, aggravation of epilepsy, insomnia, irritability, mood changes |
| Dermatological effects | easy bruising, impaired wound healing, and thinning of skin |
| Ophthalmic effects | glaucoma, corneal or scleral thinning and exacerbation of ophthalmic viral or fungal disease |
Side-effects can be minimized by using lowest effective dose for minimum period possible.
Pharmacokinetics
Betamethasone is readily absorbed from the gastrointestinal tract. It is also absorbed when given locally or use rectally as an enema. Steroid is rapidly distributed to all body tissues. They cross the placenta and may distributed in small amounts into breast milk.
Drug Management
Monitoring:
- Elderly (close supervision required particularly on long-term treatment)
- Frequent monitoring required if history of tuberculosis (or X-ray changes)
- blood sugar level, blood pressure, mood change,
- monitoring of the fluid intake and output, and daily weight records may give early warning of fluid retention.
- Sodium intake may need to be reduced and calcium and potassium supplements may be necessary.
- Back pain may signify osteoporosis
- Height should be monitored in children receiving prolonged therapy with inhaled or nasal steroid.
Drug interaction:
Interactions do not generally apply to steroid used for topical action including inhalation, unless specified.
| Drugs given with steroid | Potential adverse drug interactions |
|---|---|
| NSAIDs | Increased risk of gastro-intestinal bleeding |
| Rifampicin | Accelerate metabolism of steroid so reduce the effects of steroid |
| Antidiabetics | Steroid antagonize hypoglycaemic effect. Requirements of antidiabetics may be increased. |
Antiepileptics:
|
Accelerate metabolism of steroid so reduce the effects of steroidd |
| Endocrine side effects | menstrual irregularities and amenorrhea, hirsutism, weight gain, hyperlipidemia |
| Neuropsychiatric side effects | aggravation of schizophrenia, aggravation of epilepsy, insomnia, irritability, mood changes |
| Dermatological effects | easy bruising, impaired wound healing, and thinning of skin |
| Ophthalmic effects | glaucoma, corneal or scleral thinning and exacerbation of ophthalmic viral or fungal disease |
