Phenylpropanolamine, also known as PPA, is a psychoactive drug that has stimulant, decongestant, and anorectic effects. It works by causing the body to release its own natural stimulant chemicals — norepinephrine, epinephrine, and dopamine. It is used to treat cold and allergy symptoms and was formerly a common ingredient in over-the-counter cold remedies and weight loss preparations. In the U.S., it is no longer available without a prescription due to safety concerns after studies revealed a link between phenylpropanolamine and hemorrhagic stroke. It has also been removed from the market in some other countries.
Also known as norephedrine and oxyamphetamine, PPA belongs to the amphetamine class of drugs and has psychoactive properties. It causes stimulant, decongestant, and appetite reducing, or anorectic, action. Its method of action is to cause the body to release norepinephrine, epinephrine, and dopamine. These substances are neurotransmitters that also act as hormones in the body and are associated with the "fight or flight" response to stress. They have a stimulant action that includes increasing blood pressure, heart rate, and alertness.
Dispensed with a prescription, phenylpropanolamine is often used as a decongestant for the treatment of cold and allergy symptoms in the upper respiratory system. It works by shrinking, or constricting, the blood vessels in the nose, sinuses, and chest. This reduces swelling in these areas and allows drainage of trapped mucus from them. Common side effects include dizziness, drowsiness, lightheadedness, nervousness, nausea, headache, and insomnia. Phenylpropanolamine also was a common ingredient in many over-the-counter cold and allergy remedies.
In addition to its stimulant action, phenylpropanolamine has the ability to act as an appetite suppressant. This combination of effects is typical of many types of diet drugs. For this reason, it has been included as an ingredient in several over-the-counter weight loss preparations. These weight loss supplements have, however, been reformulated with other ingredients.
Studies have shown that there is a link between phenylpropanolamine and hemorrhagic stroke, particularly in young women. Since then, the U.S. Food and Drug Administration (FDA) has removed it from the over-the-counter market, and it's only available by prescription. It has also been removed from the market in several countries including Canada and Australia, but the drug is still available for sale in many countries in Europe such as the United Kingdom. If prescribed by a doctor, it should only be taken for a short time. It is also important for the patient to make sure that the doctor is aware of his or her complete medical history.