The most common side effects of Proscar include a decreased interest in sexual intercourse, inability to have or keep an erection, or a loss in sexual ability, desire, drive or performance. Talk to your doctor or a healthcare professional if symptoms persist or are severe.
You should contact your doctor immediately if you experience any of the following symptoms:
- Rash
- Changes in the breasts such as increased size, lumps, pain, or nipple discharge
- Itching
- Hives
- Swelling of the lips and face
- Difficulty breathing or swallowing
While rare, these symptoms require immediate medical attention. This is not a complete list of side effects associated with finasteride. Studies have shown that finasteride can increase your risk of developing breast cancer or high-grade prostate cancer, which spreads and grows more rapidly than other types of prostate cancer.
Studies have also shown that Proscar can affect the results of the prostate-specific antigen (PSA) test, which may be used to detect prostate cancer. Be sure to tell your healthcare provider that you are taking finasteride so that they are aware of any medication interference with PSA testing.
Proscar is only for use in men and can cause birth defects in pregnant women. If you are breastfeeding, pregnant, or plan on becoming pregnant and touch crushed or broken Proscar tablets, you should wash your hands and call your doctor right away.