Precautions and Warnings With Phenylephrine
Phenylephrine may not be right for you if you have certain medical conditions. Precautions and warnings with phenylephrine extend to people who have conditions such as heart disease, glaucoma, and diabetes. Also, it may not be safe to use phenylephrine if you have certain allergies or if you are pregnant or breastfeeding.
What Should I Tell My Healthcare Provider Before Taking Phenylephrine?You should talk with your healthcare provider prior to taking phenylephrine if you have:
- Heart disease
- Difficult passing urine
- An overactive thyroid (hyperthyroidism)
- An enlarged prostate (also known as benign prostatic hyperplasia, or BPH)
- Kidney disease, such as kidney failure (renal failure)
- High blood pressure (hypertension)
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Specific Phenylephrine Precautions and WarningsSome warnings and precautions to be aware of prior to taking phenylephrine include the following:
- Phenylephrine interacts with some medications. Some of these interactions can be quite dangerous (see Drug Interactions With Phenylephrine for more information).
- Phenylephrine can worsen high blood pressure (especially high blood pressure that is not well-controlled with medications or other treatments). If you have high blood pressure or heart disease, check with your healthcare provider before taking phenylephrine.
- Phenylephrine can cause problems in people with glaucoma, an enlarged prostate, diabetes, hyperthyroidism, or kidney disease. If you have one of these conditions, do not take phenylephrine without first checking with your healthcare provider.
- Phenylephrine is considered a pregnancy Category C medication. This means that it might not be safe for use during pregnancy, although the full risks are not currently known (see Phenylephrine and Pregnancy).
- It is unknown if phenylephrine passes through breast milk. Therefore, if you are breastfeeding or plan to start breastfeeding, make sure to talk with your healthcare provider before using phenylephrine (see Phenylephrine and Breastfeeding).