Indications
Naftopidil is used in men to relieve urinary symptoms caused by benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate gland. It can ease a weak stream, difficulty starting, frequent urination, getting up at night to pass urine and the feeling that the bladder has not emptied fully.
How It Works
Naftopidil is an alpha-1 blocker that acts mainly on the alpha-1D receptors found in the prostate, bladder neck and bladder. Blocking these receptors relaxes the muscle around the urinary passage, so urine flows more easily, and it may also calm an overactive bladder. It does not shrink the prostate.
Dosage and Administration
The usual adult starting dose is 25 mg once a day after a meal. Depending on response, the doctor may increase it to 50 mg to 75 mg once a day. Take the first dose at a time when you can sit or lie down if you feel dizzy. Older people may need a lower dose.
Interactions
- Other blood pressure medicines and other alpha blockers (such as Tamsulosin, Prazosin or Doxazosin) can increase the risk of low blood pressure and fainting.
- Medicines for erectile problems such as Sildenafil or Tadalafil can also add to the fall in blood pressure.
- Alcohol can make dizziness worse.
Contraindications
- Allergy to Naftopidil.
- History of fainting on standing up (orthostatic hypotension) unless a doctor advises otherwise.
- It is not intended for use in women or children.
Side Effects
Common effects include dizziness or light-headedness (especially on standing), headache, tiredness, stomach upset, stuffy nose and, sometimes, changes in ejaculation. Liver test changes can occur rarely.
Get urgent medical help if you faint, have chest pain or a fast irregular heartbeat, cannot pass urine at all, notice yellow skin or eyes, or develop signs of an allergic reaction such as swelling of the face or difficulty breathing.
Pregnancy and Lactation
Naftopidil is used only in men, so pregnancy and breastfeeding do not normally apply.
Precautions and Warnings
Stand up slowly from sitting or lying, especially after the first doses or a dose increase. Avoid driving or operating machinery until you know how it affects you. If you are planning cataract surgery, tell the eye surgeon that you take this medicine, because it can cause floppy iris syndrome during the operation. Your doctor should rule out prostate cancer before treatment. Tell your doctor about liver disease or low blood pressure.
Overdose
Too much may cause marked dizziness, fainting and low blood pressure. Lie down with the legs raised and get medical help immediately.
Therapeutic Class
Alpha-1 adrenergic receptor blocker; medicine for benign prostatic hyperplasia.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.