Drug abusers may inject drugs intended for oral use. The drugs often contain filler substances such as talc, microcrystalline cellulose, cornstarch, and crospovidone that play different functions in tablets, such as binding, providing volume, or acting as a tablet disintegrant (crospovidone). Talc or other powdery substances may also have been used by the drug dealer to dilute (“cut”) the pure drug and thus increase profits. When these substances are injected, they lodge in the lung capillaries because of their size and may cause angiothrombosis or elicit a foreign-body reaction. The physiologic consequence of widespread occlusion of small pulmonary arteries is pulmonary hypertension.