Betamethasone
Betamethasone (中文: 倍他米松)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)
Drug Names
| Generic Name | 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 |
Mechanism of Action
Immunosuppression agent,
Steroid replacement agent,
Anti-inflammatory agent
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: by slow intravenous injection: |
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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 |
Antifungals:
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Increased risk of hypokalaemia |
Antivirals:
|
Increase plasma concentration of steroid – increased risk of adrenal suppression
|
| Digoxin | Increased risk of hypokalaemia |
Diuretics:
|
antagonize diuretic effect, increased risk of hypokalaemia |
| Oral contraceptive (oestrogens) | Increase plasma concentration of steroid |
| Theophylline | Increased risk of hypokalaemia |
Caution
- Children and adolescents (growth restriction possibly irreversible)
- Osteoporosis (post-menopausal women at special risk)
- Recent myocardial infarction, congestive heart failure
- Glaucoma (including family history)
- Ocular herpes simplex – risk of corneal perforation
- Psychiatric disorders (particularly if history of steroid-induced psychosis)
- Epilepsy
- Peptic ulcer
- Hypothyroidism
- Ulcerative colitis
- Diverticulitis
- Thromboembolic disorders
- Myasthenia gravis
Contraindication:
- acute infections
- patients with active or doubtfully quiescent tuberculosis
- concurrent treatment live virus vaccines for at least 3 months afterwards
Hepatic impairment
When steroids are administered orally or parenterally, the plasma-drug concentration may be increased in patients with hepatic impairment. The patient should be monitored closely.
Renal impairment
Should be used with caution in patients with renal impairment.
Pregnancy
Betamethasone should only be used in pregnant women when benefits outweigh the risks.
- No convincing evidence that systemic steroids increase the incidence of congenital abnormalities such as cleft palate or lip.
- Prolonged use increases the risk of intra-uterine growth; but no evidence of intra-uterine growth restriction following short-term treatment.
Note
| Prolonged use of steroid | Recommendation |
|---|---|
| Immunosuppression
Prolonged use can increase susceptibility to infection |
Avoid contact with people who have chickenpox, shingles, or measles. |
| Adrenal suppression
Steroid suppresses the endogenous secretion of corticotropin by the anterior pituitary, resulting the adrenal cortex becomes atrophied. If given for more than 3 weeks, treatment must not be stopped gradually. |
Patient must mention the course of steroid when receiving treatment for intercurrent illnesses or trauma such as surgery. |
FAQ
How should I take the tablet?
Follow all directions on your prescription label. Use prednisolone exactly as directed on the label. Steroids are associated with a risk of GI irritation. The tablet MUST be with or after food to help reduce side-effects.
What should I avoid while taking?
Avoid abruptly discontinue the medication. Should not be taken with NSAIDs.
What happen if I overdose?
Contact your primary care doctor. If emergency situation, call 999
What happen if I miss a dose?
Take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
