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PRAZOSIN 0.5 MG TABLETS

Active substance(s): PRAZOSIN HYDROCHLORIDE / PRAZOSIN HYDROCHLORIDE / PRAZOSIN HYDROCHLORIDE

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Package leaflet: Information for the user
Prazosin 0.5 mg and 1 mg tablets
Prazosin hydrochloride
Read all of this leaflet carefully before you start taking this medicine because it contains
important information for you.
 Keep this leaflet. You may need to read it again.
 If you have any further questions, ask your doctor or pharmacist.
 This medicine has been prescribed for you. Do not pass it on to others. It may harm them, even
if their signs of illness are the same as yours.
 If you get any side effects, talk to your doctor or pharmacist. This includes any possible side
effects not listed in this leaflet. See section 4.
What is in this leaflet:
1. What Prazosin is and what it is used for
2. What you need to know before you take Prazosin
3. How to take Prazosin
4. Possible side effects
5. How to store Prazosin
6. Contents of the pack and other information

1.

What Prazosin is and what it is used for

Your tablets are called Prazosin Tablets. They are part of a group of drugs known as alphaadrenoceptor blocking drugs (alpha-blockers).
Prazosin is used:
 in the treatment of high blood pressure (hypertension) by widening the blood vessels and
lowering the blood pressure
 in the treatment of heart failure, a condition where the heart’s pumping action is not strong
enough and leads to a build-up of fluid in the lungs and tissues
 in the symptomatic treatment of Raynaud’s disease (painful cold fingers) by relaxing the blood
vessels in the hands and feet so blood can reach your hands and feet more easily. This helps to
prevent coldness and stiffness
 in the symptomatic treatment of Prostatic Hyperplasia in men (mild enlargement of the prostate
gland) to relieve poor and/or frequent passing of urine. This works by relaxing the muscle
around the bladder and prostate gland so that you can pass urine more easily.

2. What you need to know before you take Prazosin
Do not take Prazosin:
 if you are allergic to Prazosin, other similar drugs known as quinazolines e.g. doxazosin or any
of the other ingredients of this medicine (listed in section 6).
 if you have congestive heart failure (condition in which the heart is not strong enough to pump
blood efficiently around the body so fluid collects in the lungs and body tissue and causes
congestion) caused by mechanical obstruction e.g. aortic stenosis (narrowing of the aortic valve
in the heart).

Warnings and precautions
Talk to your doctor or pharmacist before taking Prazosin Tablets.
Some patients will feel faint or collapse after the first dose of Prazosin Tablets and if this happens
you should lie down for a while. Please bear this in mind when you start to take your tablets.
Tell your doctor before you start to take this medicine:
 if you have an enlarged prostate
 if you have heart failure due to a recent heart attack
 if you have had a recent pulmonary embolism (breathing difficulty due to a blood clot in the
lungs)
 if you have ever fainted after passing urine
 if you have kidney or liver failure
 if you are to have cataract surgery on your eye.
If you are undergoing eye surgery because of cataract (cloudiness of the lens) please inform your
eye specialist before the operation that you are using or have previously used Prazosin. This is
because Prazosin may cause complications during the surgery which can be managed if your
specialist is prepared in advance.
Some patients who take Prazosin for the treatment of high blood pressure or prostate enlargement
may experience dizziness or light-headedness, which may be caused by low blood pressure upon
sitting or standing up quickly. Certain patients have experienced these symptoms when taking drugs
for erectile dysfunction (impotence) with Prazosin. In order to reduce the likelihood that these
symptoms occur, you should be on a regular daily dose of Prazosin before you start drugs for
erectile dysfunction.
If you have any tests, such as blood or urine tests, make sure that the doctor or nurse knows that you
are taking Prazosin, as it can affect the results of some tests.
Other medicines and Prazosin Tablets
Tell your doctor if you are taking or have recently taken or might take any other medicines.
Talk to your doctor if you are taking any of the following:
 thiazide diuretics (water tablets) e.g. bendroflumethiazide
 calcium antagonists (e.g. diltiazem), ACE inhibitors (e.g. lisinopril, ramipril) or beta blockers
(e.g. propranolol)
 medicines for erectile dysfunction (impotence, e.g. sildenafil, tadalafil).
Pregnancy, breast-feeding and fertility


If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby,
ask your doctor for advice before taking this medicine.

Driving and using machines
 Prazosin may make you feel dizzy, weak, drowsy or have blurred vision. If you are affected, do
not drive or operate machinery.

Prazosin contains lactose and dispersed orange (E110)
 Patients who are intolerant to lactose should note that Prazosin tablets contain a small amount
of lactose. If your doctor has told you that you have an intolerance to some sugars, contact your
doctor before taking this medicine.
 The 1 mg tablets contain dispersed orange (E110) as a colouring agent. E110 may cause
possible allergic reactions, including asthma. If you are allergic to aspirin, you are more likely
to suffer a reaction.

3. How to take Prazosin
Always take this medicine exactly as your doctor has told you. Check with your doctor or
pharmacist if you are not sure.
The tablets should be swallowed preferably with a drink of water. The usual dose is:
Adults
 High Blood Pressure
The recommended starting dose is 0.5 mg 2-3 times daily for the first 3-7 days days. The first
dose should be taken in the evening.
The dose is usually increased to 1 mg 2-3 times daily for a further 3-7 days.
Your doctor may then gradually increase this dose to a maximum of 20 mg a day depending on
how you have responded to treatment.
Your medicine can be taken when taking other medicines for hypertension. Your doctor will
adjust your dose accordingly.


Congestive heart failure
The recommended starting dose is 0.5 mg, 2-4 times daily. The first dose should be taken in the
evening.
The dose is usually increased gradually to 4 mg daily in divided doses. Your doctor may then
gradually increase this dose to a maximum of 20 mg a day depending on how you have
responded to treatment.



Raynaud’s disease
The recommended starting dose is 0.5 mg twice daily for the first 3-7 days. The first dose
should be taken in the evening.
The usual maintenance dose is 1-2 mg twice daily.



Enlarged prostate
The recommended starting dose is 0.5 mg twice daily for 3-7 days. The first dose should be
taken in the evening.
The usual maintenance dose is 2 mg twice daily.

Elderly
 Treatment should be started at the lowest dose possible.
Use in children and adolescents
Children
 Prazosin is not recommended for use in Children under the age of 12 years.

If you take more Prazosin than you should
If you (or someone else) swallow a lot of the tablets all together, or if you think a child has
swallowed any of the tablets, contact your nearest hospital casualty department or your doctor
immediately.
Please take this leaflet, any remaining tablets, and the container with you to the hospital or doctor
so that they know which tablets were consumed.
If you forget to take Prazosin
If you forget to take a tablet, take one as soon as you remember, unless it is nearly time to take the
next one. Do not take a double dose to make up for a forgotten dose.
If you stop taking Prazosin
Do not stop taking your medicine without talking to your doctor first even if you feel better.
If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Some patients will feel faint or collapse after the first dose of Prazosin Tablets (see section 2, Take
special care with Prazosin).
Stop taking the tablets and tell your doctor immediately or go to the casualty department at your
nearest hospital if the following happens:
 an allergic reaction causing swelling of the lips, face or neck leading to severe difficulty in
breathing, skin rash or hives.
This is a very serious but rare side effect. You may need urgent medical attention or
hospitalisation.
The following side effects have been reported at the approximate frequencies shown:
Common: may affect up to 1 in 10 people
 feeling faint, fainting or feeling dizzy, particularly on standing-up
 headache, drowsiness or weakness
 unpleasant sensation of forceful beating of the heart (palpitations)
 lack of energy, depression or nervousness
 constipation, diarrhoea, feeling sick (nausea), or being sick (vomiting)
 dry mouth, nasal stuffiness
 blurred vision
 shortness of breath or rash
 swelling of the feet, ankles or legs
 increase in frequency of passing urine
 inability or difficulty in achieving erection of the penis.
Uncommon: may affect up to 1 in 100 people
 stomach discomfort and/or pain
 chest pain or abnormally fast heart beat
 tingling sensation or numbness
 buzzing or ringing in the ear






nose bleeds, eye pain or red eyes
difficulty sleeping
sweating, itching or itchy skin rash
painful joints.

Rare: may affect up to 1 in 1,000 people
 abnormal blood tests that check for liver function
 pain or infection in the pancreas
 abnormally slow heartbeat
 hallucinations (imagining things which are not really there)
 hair loss
 low blood pressure
 flushing (redness)
 positive ANA (a blood test that checks function of the immune system)
 abnormal breast tissue development, especially in men
 persistent erection of the penis
 an increased tendency to fall asleep if you have a sleep disorder (narcolepsy)
 leaking of urine (incontinence)
 fever or pain
 inflammation of blood vessels.
Reporting of side effects
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects
not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at:
www.mhra.gov.uk/yellowcard.
By reporting side effects you can help provide more information on the safety of this medicine.

5.

How to store Prazosin

Keep this medicine out of the sight and reach of children.
Store in a cool, dry place. Protect from light and moisture.
Do not use this medicine after the expiry date which is stated on the outer packaging. The expiry
date refers to the last day of that month.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to
throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information
What Prazosin tablets contain(s):


The active substance is prazosin hydrochloride. Each tablet contains 0.5 mg or 1 mg of
prazosin hydrochloride. The other ingredients are lactose, pre-gelatinised starch, povidone,
isopropanol, sodium starch glycolate and magnesium stearate. The 1 mg tablets also contain
colour dispersed orange (E110).

What Prazosin tablets look like and contents of the pack:
 Prazosin 0.5 mg are white tablets coded PRZ 0.5 on one side and a twin triangle logo on the
reverse
 Prazosin 1 mg tablets are orange tablets coded PRZ 1.0 on one side and a twin triangle logo on
the reverse
 Prazosin tablets are available in packs of 7, 14, 21, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120,
250, 500 and 1000 tablets.
Not all pack sizes may be marketed.
Marketing Authorisation Holder and Manufacturer
Marketing Authorisation holder and company responsible for manufacture: Teva UK Limited,
Eastbourne, BN22 9AG
This leaflet was last revised: December 2015
PL 00289/1530-1531

Expand Transcript

Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.

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