Drug Groups

approved; withdrawn

Description

Phenylpropanolamine has been withdrawn in Canada. In November 2000, the Food and Drug Administration (FDA) issued a public health advisory against the use of the drug.

Indication

For the treatment of nasal congestion, control of urinary incontinence, priapism and obesity.

Pharmacology

Phenylpropanolamine (PPA), a sympathomimetic agent structurally similar to pseudoephedrine, is used to treat nasal congestion. Phenylpropanolamine is found in appetite suppressant formulations and with guaifenesinin in cough-cold formulations. In 2000, the FDA requested that all drug companies discontinue marketing products containing phenylpropanolamine, due to an increased risk of hemorrhagic stroke in women who used phenylpropanolamine.

Toxicity

May induce ventricular extrasystoles and short paroxysms of ventricular tachycardia, a sensation of fullness in the head and tingling of the extremities; LD₅₀=1490mg/kg (orally in rat)

Affected Organisms

Biotransformation

Hepatic

Absorption

Reduced bioavailability (about 38%) from gastrointestinal tract because of first pass metabolism by monoamine oxidase in the stomach and liver.

Half Life

2.1 to 3.4 hours.

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