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.
The cause of low blood pressure isn't always clear. It may be associated with the following: Pregnancy. Hormonal problems, such as an underactive thyroid (hypothyroidism), overactive thyroid (hyperthyroidism), diabetes, or low blood sugar (hypoglycaemia)