This is the retyped text of a talk paper from the FDA
FDA officials are concerned that taking more than the recommended dose of PPA, an ingredient in OTC weight control, cough-cold, allergy, and nasal decongestant drug products, may be harmful. Some data indicate that PPA, in OTC drugs, may increase the risk of hemorrhagic stroke. Although FDA agrees with the conclusion that, to date, there is no definite link between using over-the-counter PPA-containing drugs and hemorrhagic strokes, the agency believes further safety data are needed. FDA awaits these data from an industry-sponsored PPA safety study.
In the interim, the agency believes that it should require enhanced, directive warnings on how consumers can safely use these products.
Hemorrhagic strokes differ from ischemic strokes in that they result from bleeding into the brain. Ischemic strokes result from a blood vessel blockage that impairs the blood flow to the brain.
In reviewing all available information, it appears that PPA's possible risk may be further increased when consumers inadvertently exceed normal doses either by consuming more than the label's recommended dose or by simultaneously taking the drug in other products labeled for different uses (i.e. taking PPA-containing weight control and cough/cold products).
PPA affects the central nervous system and the cardiovascular system and should not be taken with other products that contain PPA, phenylephrine, pseudoephedrine or ephedrine, which have similar effects on the body. PPA also interacts with certain antidepressants known as monoamine oxidase inhibitors (MAOI), which when combined with PPA can cause life-threatening adverse effects. In addition, persons with high blood pressure, heart or thyroid disease, or diabetes should not use PPA without consulting a doctor.