The different formulations, including Bimix and Trimix, may include papaverine and/or phentolamine. The active ingredients in the mixture are usually alprostadil, papaverine, and phentolamine. Both species contain morphine and papaverine, powerful opiates. Papaverine is used as an erectile dysfunction drug, alone or sometimes in combination. Papaverine is available as a conjugate of hydrochloride, codecarboxylate, adenylate, and teprosylate. Papaverine, an opium alkaloid, has been reported to act as a PDE10 inhibitor. Because of its reliance on CYP3A4, reboxetine "O"-desethylation is markedly inhibited by papaverine and ketoconazole. The ingestion of large doses of papaverine in the vegetable Sauropus androgynus has caused it. Some inhibitors include papaverine, PF-2545920, TC-E 5005, and tofisopam. Papaverine is used as an off label prophylaxis (preventative) of migraine headaches. Other contaminants used in urine samples alongside noscapine include papaverine and acetylcodeine. Isoquinolines such as papaverine and noscapine have no significant central nervous system effects.