Medically reviewed by Jessica Swirble, PharmD
Last updated on 6/17/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of tamsulosin can lead to various side effects in some individuals.

Common mild side effects of tamsulosin use include:

• Drowsiness
  
• Insomnia
  
• Weakness
  
• Runny or stuffy nose
  
• Back pain
  
• Headache
  
• Sore throat, chills, fever
  
• Blurred vision
  
• Dizziness
  
• Diarrhea
  
• Nausea
  
• Difficulty with ejaculation (in men)
  
  

More severe side effects include:

• An erection that lasts for more than 4 hours
  
• Faintness
  
• Low blood pressure
  
• Signs of an allergic reaction (like hives, skin rash, chest pain, difficulty breathing)
  
  

If you experience any severe or concerning side effects while taking tamsulosin, contact your healthcare provider right away.

Inform your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with tamsulosin. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with tamsulosin.

Tell your provider if you are taking these medications or supplements:

• Other alpha-blocker medications such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), and terazosin (Hytrin)
  
• Anticoagulants (blood thinners)
  
• Cimetidine (Tagamet)
  
• Ranolazine (Ranexa)
  
• Medications for erectile dysfunction
  
• Antibiotics and antivirals
  
• Heart rhythm medications
  
• Blood pressure medications
  
  

You should also mention medical conditions such as:

• Prostate cancer
  
• Liver disease
  
• Kidney disease
  
• Orthostatic hypotension
  
• Cataracts
  
  

If you are pregnant, planning to become pregnant, or breastfeeding, discuss the potential risks and benefits of using tamsulosin with your healthcare provider.

Take tamsulosin exactly as prescribed by your healthcare provider. Do not exceed the recommended dose or duration of treatment.

Your provider may direct you to take tamsulosin 30 minutes after the same meal each day (i.e., breakfast or dinner).

Complete the full course of treatment, even if you feel better, to ensure the medication's effectiveness in managing your condition.

In case of a tamsulosin overdose, seek medical attention immediately. Symptoms of overdose may include severe dizziness, fainting, or a rapid heartbeat. If you suspect an overdose, contact the poison control helpline at 1-800-222-1222 or call emergency services.