Do NOT use Hytrin if:

• you are allergic to any ingredient in Hytrin or to similar medicines (eg, prazosin).

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Hytrin. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have prostate cancer, angina pectoris, heart disease, or kidney or liver problems
• if you will be having eye surgery.

Some medicines may interact with Hytrin. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Phosphodiesterase type 5 (PDE5) inhibitors (eg, sildenafil) or verapamil because severe dizziness, lightheadedness, or fainting may occur.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Hytrin may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Hytrin may cause drowsiness, dizziness, blurred vision, or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use Hytrin with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Hytrin; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
• Hytrin may cause a sudden drop in blood pressure after the first dose. Take your first dose at bedtime. If you get up during the night, sit up slowly, then stand slowly. This will help to reduce your lightheadedness or dizziness. These effects are more likely to occur after the first few doses or if your dose has increased, but can occur at any time while you are taking the medicine. It can also occur if you stop taking the medicine and then restart treatment.
• Hytrin may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
• Patients who take medicine for high blood pressure often feel tired or run down for a few weeks after starting treatment. Be sure to take your medicine even if you may not feel "normal." Tell your doctor if you develop any new symptoms.
• Do NOT take more than the recommended dose without checking with your doctor.
• Hytrin may rarely cause a prolonged, painful erection. This could happen even when you are not having sex. If this is not treated right away, it could lead to permanent sexual problems such as impotence. Contact your doctor right away if this happens.
• Tell your doctor or dentist that you take Hytrin before you receive any medical or dental care, emergency care, or surgery (including eye surgery).
• Lab tests, including blood pressure, may be performed while you use Hytrin. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Hytrin should not be used in children; safety and effectiveness in children have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Hytrin while you are pregnant. It is not known if Hytrin is found in breast milk. If you are or will be breast-feeding while you use Hytrin, check with your doctor. Discuss any possible risks to your baby.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Dizziness; drowsiness; lightheadedness; nasal congestion; nausea; weakness.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision or other vision changes; chest pain; decreased sexual desire or ability; fainting; fast, slow, or irregular heartbeat;painful, prolonged erection; severe or prolonged dizziness or headache; shortness of breath; swelling of the ankles, feet, or hands.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.