General
Description & Use
Used
to treat high blood pressure. It also is used to prevent angina
(chest pain) and heart attacks. Propranolol can be used to treat
abnormal heart rhythms. Propranolol is also used to prevent migraine
headaches and tremors. Propranolol is a non-selective beta blocker
mainly used in the treatment of hypertension. It was the first
successful beta blocker developed. It is the only drug proven
effective for the prophylaxis of migraines in children.
Additional
Information
Propranolol (Inderal, Ciplar-LA) is a non-selective beta blocker,
that is, it blocks the action of epinephrine on both ß1-
and ß2 adrenergic receptors. It has little intrinsic sympathomimetic
activity (ISA) but has strong membrane stabilizing activity (only
at high blood concentrations, eg overdosage). Only L-propranolol
is a powerful adrenoceptor antagonist, whereas D-propranolol is
not. However, both have local anesthetic (termed topical) effect.
Propranolol is rapidly and completely absorbed, with peak plasma
levels achieved approximately 1–3 hours after ingestion.
Co-administration with food appears to enhance bioavailability.
Despite complete absorption, propranolol has a variable bioavailability
due to extensive first-pass metabolism. Hepatic impairment will
therefore increase its bioavailability. The main metabolite 4-hydroxypropranolol,
with a longer half-life (5.2–7.5 hours) than the parent
compound (3–4 hours), is also pharmacologically active.
Propranolol
is a highly lipophilic drug achieving high concentrations in the
brain. The duration of action of a single oral dose is longer
than the half-life and may be up to 12 hours, if the single dose
is high enough (e.g., 80 mg). Effective plasma concentrations
are between 10–100 ng/ml.
Propranolol
is indicated for the management of various conditions including:
Propranolol is also used to lower portal vein pressure in portal
hypertension and prevent oesophageal variceal bleeding. Propranolol
is often used by musicians and other performers to prevent stage
fright. Propranolol is currently being investigated as a potential
treatment for post-traumatic stress disorder
Propranolol
should be used with caution in patients with:
