Fentanyl is available as a skin patch, lozenge, pills, shots, a film that dissolves in your mouth, nasal spray, or by IV (intravenous) . Use fentanyl exactly as prescribed by your doctor. This is very important so that you do not get too much of the drug.entanyl is available as a skin patch, lozenge, pills, shots, a film that dissolves in your mouth, nasal spray, or by IV (intravenous) . Use fentanyl exactly as prescribed by your doctor. This is very important so that you do not get too much of the drug.
Some medical conditions can cause low blood pressure. These include: 1  Pregnancy. 2  Because a woman's circulatory system expands rapidly during pregnancy, blood pressure is likely to drop. 3  This is normal, and blood pressure usually returns to your pre-pregnancy level after you've given birth.
Low blood pressure also occurs when the nerves that conduct signals between the brain and the heart and blood vessels are impaired by neurologic disorders calledautonomic neuropathies. When a person quickly moves from a sitting position to a standing position, blood pressure in the blood vessels to the brain decreases, resulting in a temporary sensation of lightheadedness or faintness.