Dexamethasone 8mg/ 2 ml solution for injection can be given without mixing or dilution, but if preferred, can be added without loss of potency to sodium chloride injection or dextrose injection and given by intravenous drip. The infusion mixture must be used within 24 hours and the usual aseptic techniques for injections should be observed.
Solutions used for intravenous administration or further dilution of this product should be preservative-free when used in the neonate, especially the premature infant.
All dosage recommendations are given in units of dexamethasone base.
Intravenous and intramuscular injection
General considerations
Dosage must be individualised on the basis of the disease and the response of the patient. In order to minimise side effects, the lowest possible dosage adequate to control the disease process should be used
Usually the parenteral dosage ranges are one-third to one-half of the oral dose, given every 12 hours.
The usual initial dosage is 0.4 mg – 16.6 mg (0.12 ml – 5.0 ml) a day. In situations of less severity, lower doses will generally suffice. However, in certain overwhelming, acute, life-threatening situations, administration in dosages exceeding the usual dosage may be justified. In these circumstances, the slower rate of absorption by intramuscular administration should be recognised.
Both the dose in the evening, which is useful in alleviating morning stiffness and the divided dosage regimen are associated with greater suppression of the hypothalamopituitary-adrenal axis. After a favourable response is noted, the proper maintenance dosage should be determined by decreasing the initial dosage by small amounts at appropriate intervals to the lowest dosage which will maintain an adequate clinical response. Chronic dosage should preferably not exceed 500 micrograms dexamethasone daily. Close monitoring of the drug dosage is needed.
To avoid hypoadrenalism and/or a relapse of the underlying disease, it may be necessary to withdraw the drug gradually .
Whenever possible, the intravenous route should be used for the initial dose and for as many subsequent doses as are given while the patient is in shock (because of the irregular rate of absorption of any medicament administered by any other route in such patients). When the blood pressure responds, use the intramuscular route until oral therapy can be substituted. For the comfort of the patient, not more than 2 ml should be injected intramuscularly at any one site.
In emergencies, the usual dose of Dexamethasone 8 mg/ 2ml solution for injection by intravenous or intramuscular injection is 3.3 mg – 16.6 mg (1.0 ml – 5.0 ml) – in shock use only the i.v. route. This dose may be repeated until adequate response is noted.
After initial improvement, single doses of 1.7 mg – 3.3 mg (0.5 ml – 1.0 ml), repeated as necessary, should be sufficient. The total daily dosage usually need not exceed 66.4 mg (20.0 ml), even in severe conditions.
When constant maximal effect is desired, dosage must be repeated at three-hour or four-hour intervals or maintained by slow intravenous drip.
Intravenous or intramuscular injections are advised in acute illness. When the acute stage has passed, oral steroid therapy should be substituted as soon as feasible.
Shock (of haemorrhagic, traumatic, or surgical origin):
Usually 1.7 mg – 5.0 mg/kg (0.5 ml – 1.5 ml/kg) bodyweight as a single intravenous injection. This may be repeated in two to six hours if shock persists. Alternatively, this may be followed immediately by the same dose in an intravenous infusion.
Therapy with Dexamethasone 3.3 mg/ml solution for injection is an adjunct to and not a replacement for conventional therapy.
Administration of these high doses should be continued only until the patient’s condition has stabilised and usually no longer than 48-72 hours.
Cerebral oedema:
Associated with primary or metastatic brain tumour, preoperative preparation of patients with increased intracranial pressure secondary to brain tumour: initially 8.3 mg (2.5ml) intravenously, followed by 3.3 mg (1.0 ml) intramuscularly every six hours until symptoms of cerebral oedema subside. Response is usually noted within 12-24 hours; dosage may be reduced after two to four days and gradually discontinued over five to seven days.
High doses of Dexamethasone 8 mg/2ml solution for injection are recommended for initiating short-term intensive therapy for acute life-threatening cerebral oedema.
Following the high-loading dose schedule of the first day therapy, the dose is scaled down over the seven- to ten- day period of intensive therapy and subsequently reduced to zero over the next seven to ten days. When maintenance therapy is required, substitute oral dexamethasone as soon as possible .
Palliative management of recurrent or inoperable brain tumours:
Maintenance therapy should be determined for each patient; 1.7 mg (0.5 ml) two or three times a day may be effective.
The smallest dose necessary to control cerebral oedema should be used.
Suggested high-dose schedule in cerebral oedema
Adults:
Initial dose 41.5 mg (12.5 ml) i.v.
1st day – 6.6 mg (2.0 ml) i.v. every 2 hours
2nd day – 6.6 mg (2.0 ml) i.v. every 2 hours
3rd day – 6.6 mg (2.0 ml) i.v. every 2 hours
4th day – 3.3 mg (1.0 ml) i.v. every 2 hours
5th-8th days – 3.3 mg (1.0 ml) i.v. every 4 hours
Thereafter decrease by daily reduction of 3.3 mg (1.0 ml)
Children (35 kg and over):
Initial dose 20.8 mg (6.25 ml) i.v.
1st day – 3.3 mg (1.0 ml) i.v. every 2 hours
2nd day – 3.3 mg (1.0 ml) i.v. every 2 hours
3rd day – 3.3 mg (1.0 ml) i.v. every 2 hours
4th day – 3.3 mg (1.0 ml) i.v. every 4 hours
5th-8th days – 3.3 mg (1.0 ml) i.v. every 6 hours
Thereafter decrease by daily reduction of 1.7 mg (0.5 ml)
Children (below 35 kg):
Initial dose 16.6 mg (5.0 ml) i.v.
1st day – 3.3 mg (1.0 ml) i.v. every 3 hours
2nd day – 3.3 mg (1.0 ml) i.v. every 3 hours
3rd day – 3.3 mg (1.0 ml) i.v. every 3 hours
4th day – 3.3 mg (1.0 ml) i.v. every 6 hours
5th-8th days – 1.7 mg (0.5 ml) i.v. every 6 hours
Thereafter decrease by daily reduction of 0.83 mg (0.25 ml)
Dual therapy:
In acute self-limiting allergic disorders or acute exacerbations of chronic allergic
disorders, the following schedule combining oral and parenteral therapy is suggested:
First day: Dexamethasone 3.3 mg/ml solution for injection, 3.3 mg – 6.6 mg (1.0 ml – 2.0 ml) intramuscularly
Second day: Two 500 microgram dexamethasone tablets twice a day
Third day: Two 500 microgram dexamethasone tablets twice a day
Fourth day: One 500 microgram dexamethasone tablet twice a day
Fifth day: One 500 microgram dexamethasone tablet twice a day
Sixth day: One 500 microgram dexamethasone tablet once daily
Seventh day: One 500 microgram dexamethasone tablet once daily
Eighth day: Reassessment day.
Intraarticular, intrabursal or intralesional injection
In general, these injections are employed when only one or two joints or areas are
Some of the usual single doses are:
Site of injection
|
Dexamethasone dose
|
Large joint (e.g. knee) |
1.7 mg – 3.3 mg (0.5 ml – 1.0 ml) |
Small joints (e.g. interphalangeal, temporomandibular) |
0.66 mg – 0 .8 mg (0.2 ml – 0.25 ml) |
Bursae |
1.7 mg – 2 .5 mg (0.5 ml – 0.75 ml) |
Ganglia |
0.8 mg – 1.7 mg (0.25 ml – 0.5 ml) |
Tendon sheaths* |
0.33 mg – 0.8 mg (0.1 ml – 0.25 ml) |
Soft-tissue infiltration |
1.7 mg – 5.0 mg (0.5 ml – 1.5 ml) |
*Injection should be made into the tendon sheath and not directly into the tendon.
Frequency of injection: once every three to five days to once every two to three weeks, depending on response.
Use in children:
- Dosage should be limited to a single dose on alternate days to lessen retardation of growth and minimise suppression of the hypothalamo-pituitary adrenal axis.
Use in the elderly:
- Treatment of elderly patients, particularly if long term, should be planned bearing in mind the more serious consequences of the common side effects of corticosteroids in old age, especially osteoporosis, diabetes, hypertension, hypokalaemia, susceptibility to infection and thinning of the skin. Close clinical supervision is required to avoid life threatening reactions.