Page 87 - pharma 1 theoretical updated MNU_Neat

Clinical pharmacy 2024/2025 Level 3 Pharm D Pharmacology 1 (PO 502)

8- α/β Adrenoreceptors blocking gents

➢ Labetalol and carvedilol ➔ block α1, β1, and β2 receptors.
➢ Carvedilol ➔ effective antihypertensive, is mainly used in the treatment of heart
failure.

➢ Carvedilol& metoprolol [selective β1 antagonist]➔ ↓ morbidity and mortality
associated with heart failure.
9- Centrally acting adrenergic drugs

Clonidine α-methyldopa
α2- agonist (auto regulatory receptor) α2-agonist ➔converted to methyl

➔ ↓central adrenergic outflow ➔ norepinephrine centrally to
MOA
↓firing rate of sympathetic nerves & diminish adrenergic outflow from
↓ amount of NE release. the CNS.

➢ Primarily for the treatment of
resistant hypertension ➔ not ➢ treating hypertensive patients
responded adequately to treatment with renal insufficiency.

Uses with two or more drugs. ➢ hypertensive pregnant
➢ Because it may cause sodium and patients.
water retention, clonidine may be (Almost reserved to this use) to

administrated in combination with avoids Eclampsia
a diuretic.
➢ Doesn’t decrease renal blood flow ➢ ↓total peripheral resistance ➔

or glomerular filtration➔ useful ↓blood pressure.
Action/
in the treatment of hypertension ➢ Cardiac output is not decreased,
Advantages complicated by renal disease and blood flow to vital organs

(kidney) is not diminished ➔
so used in renal failure

Mild → sedation, dry mouth, and
ADR sedation and drowsiness.
constipation.

Rebound hypertension ➔ if drug

stopped suddenly ➔ NE ↑ to high
values and may cause cardiac arrest.
Caution occurs following abrupt withdrawal

of clonidine. [The drug should,
therefore, be withdrawn slowly if the
clinician wishes to change agents]

| P a g e - 71 -