Clonidine stimulation test
SPEG (Scottish Paediatric Endocrine Group)
- Fast the patient overnight (4h for infants), and measure height and weight.
- Calculate surface area from appropriate tables.
- Start the test by 09:00h whenever possible.
Drug(s) Given
Clonidine 150 micrograms per m2 body surface area.
Round the dose up to the nearest 25 micrograms.
How Given
Given orally with a small sugar free drink.
Timing of Administration
Give after the two basal blood samples have been taken.
| Time (minutes) | Action |
| -30 | Insert a reliable cannula. Take venous blood sample. |
| 0 | Take venous blood sample. Give oral clonidine dose. |
| 15 | Take venous blood sample. |
| 30 | Take venous blood sample. |
| 60 | Take venous blood sample. |
| 90 | Take venous blood sample. |
| 120 | Take venous blood sample. |
| 150 | Take venous blood sample. |
(Please view this table in landscape mode on mobile devices)
| Time (minutes) | ||||||||
| -30 | 0 | 15 | 30 | 60 | 90 | 120 | 150 | |
| GH |  |
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| IGF1 | |
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| T4, TSH | |
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- Once the test is completed, make sure the child has had something to eat and drink.
- Side effects of Clonidine (hypotension and drowsiness) may persist for several hours after the test.
- Keep the patient lying down for at least an hour after the test.
- Check pulse and blood pressure half-hourly and also before allowing the child to get up.
- Careful observation of the patient is necessary until late afternoon.
If the plasma GH concentration reaches 6.7 micrograms/L or more, further investigations are not necessary.
If the response is below this level, then an insulin hypoglycaemia test may be necessary.