Pharmacological actions
*Competes with dopa for dopa decarboxylase enzyme leading to formation of alpha methyl norepinephrine (false chemical transmitter) Which:
- activates inhibitory a2 receptor in the medullary region leading to inhibition of the sympathetic outflow
- Inhibits plasma renin activity
- Antihypertensive
Therapeutic Uses
Used for pregnancy mostly due to negligble side effects - but it has weak therapeutic effects - Treatment of hypertension. (in pregnant female and in chronic renal failure) because it does not affect the heart rate, COP, renal, cerebral or myocardial blood flow.
Adverse effects
- Drowsiness (common and disappears with continued treatment).
- Depression (Less than reserpine).
- Nasal stuffiness.
- Drug fever.
- Salt and water retention.
- Liver damage; if long term
- Bone marrow depression.
- Positive Commb’s test.
For Pregnancy + Hypertention 1- a methyl dopa 2- Hydrolazine; may cause rash 3- Labetalol; cant be used with diabetes 4- Nifidipine …
