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PRAZOSIN (HYPOVASE)

Brand Name(s) : Hypovase
Warnings
Uses
Side Effects
Precautions
Interactions
Overdose

PRAZOSIN WARNINGS

Prazosin should be used with caution in: the elderly, children under 12 years of age, women who are pregnant, likely to get pregnant, or who are breastfeeding, those with liver or kidney problems, or those undergoing cataract surgery.

It should not be used in: patients who have a history of postural hypotension (a fall in blood pressure when moving from lying to sitting, or from sitting to standing), a history of fainting shortly after or during urination (micturition syncope), or those with congestive heart failure (a condition in which the heart is unable to deliver sufficient oxygen-rich blood to the body to meet the body's needs) owing to a mechanical obstruction such as aortic stenosis (narrowing of one of the valves in the heart).

Also see list of precautions and interactions.

STORAGE

Store below 30°C.

PRAZOSIN USES

What is it used for?

  • Prazosin is used to treat a number of problems.
  • It is a selective alpha-blocker, sometimes called an alpha blocker or an alpha-1 blocker.
  • It is used to relax the prostate gland muscle, allowing the passage of urine in patients with benign prostatic hyperplasia (in which the prostate is enlarged, squeezing the urethra, the tube that allows urine to pass from the bladder to the outside of the body). It is also a vasodilator (it allows blood vessels to become wider, and so allow blood to flow at a lower pressure).
  • In general this drug is used to treat the symptoms of benign prostatic hypertrophy such as problems with urination (passing water), as well as the treatment of high blood pressure (hypertension), or in congestive heart failure (a condition in which the heart is unable to deliver sufficient oxygen-rich blood to the body to meet the body's needs; prazosin allows the heart to pump blood more easily, and is used when other drugs are not working), and in Raynaud's disease (restricted blood flow to the extremities such as the fingers and toes, a colour change in the skin of these areas to yellow or white, which may become cold and numb).
  • Benefits of being on this drug can include an increase in urine flow rate, improvement in some of the symptoms of urine-flow obstruction, reductions in blood pressure in patients with high blood pressure, relief from some symptoms of congestive heart failure, and for the management of Raynaud's disease symptoms, preventing coldness and stiffness of fingers and toes.

Listed below are the typical uses of prazosin.

  • Treatment of the functional symptoms of benign prostatic hypertrophy (such as difficulty urinating)
  • Treatment of high blood pressure
  • Treatment of congestive heart failure resistant to treatment with conventional drug treatments
  • Treatment of symptoms of Raynaud's disease (or Raynaud's syndrome, which consists of Raynaud's disease symptoms, but because of another disease such as arthritis).

On occasion your doctor may prescribe this medicine to treat a condition not on the above list. Such conditions are listed below.

  • None.

HOW TO USE/TAKE

How often do I take it?

  • Take this medication by mouth, usually two- to four-times daily (depending on the condition being treated).
  • Use this medication regularly in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told otherwise by your doctor.
  • It may take some time before the full benefit of this drug takes effect.
  • Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • This medication may cause dizziness or weakness, and if so you should consider avoiding driving or operating machinery. Consult your doctor or pharmacist for more details.

When can I stop?

  • It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop.

PRAZOSIN SIDE EFFECTS

This is not a complete list of possible side effects. If any of these persist or you consider them severe then inform your doctor.

Tell your doctor immediately if you develop any of the following symptoms: palpitations (pounding in the chest) or blurred sight.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.

PRAZOSIN PRECAUTIONS

Before taking prazosin, tell your doctor or pharmacist if you are allergic to it; or to other alpha-blockers; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: postural hypotension (a fall in blood pressure when moving from lying to sitting, or from sitting to standing, and leading to dizziness or fainting), micturition syncope (fainting shortly after or during urination), or congestive heart failure (a condition in which the heart is unable to deliver sufficient oxygen-rich blood to the body to meet the body's needs) owing to a mechanical obstruction such as aortic stenosis (narrowing of one of the valves in the heart).

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: feeling faint or dizzy (or fainting) when standing up, any liver or kidney problems, or fainting after or during urination.

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • Take care if drinking alcohol as this may have an additional blood pressure-lowering effect.

The elderly: prazosin should be used with caution in the elderly as it may be more likely to cause side-effects than in younger patients.

Pregnancy and breastfeeding - please ensure you read the detailed information below

PREGNANCY

The safety of prazosin has not been established during pregnancy. Ask your doctor or pharmacist if you have any doubts or questions about this.

It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.

BREAST FEEDING

Prazosin is secreted in breast milk in small quantities. You should take prazosin only if your doctor thinks you need it.

It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.

PRAZOSIN INTERACTIONS

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

This drug should not be used with the following medications because very serious, possibly fatal interactions may occur:

If you are currently using any of these medications, tell your doctor or pharmacist before starting prazosin.

Before using this medication, tell your doctor or pharmacist of all prescription and non-prescription/herbal products you may use, especially of:

  • Antihypertensive drugs, particularly beta-blockers (e.g. atenolol, propanolol or bisoprolol) or calcium-channel blockers (e.g. amlodipine, diltiazem, felodipine or verapamil)
  • Antidepressants (monoamine oxidase inhibitors or MAOIs)
  • Diuretics (e.g. bendroflumethiazide or furosemide)
  • Erectile dysfunction treatments (e.g. sildenafil, vardenafil, tadalafil)
  • General anaesthetics
  • Moxisylyte, used to treat Raynaud's syndrome.

This information does not contain all possible interactions. Therefore, before using prazosin, tell your doctor or pharmacist of all the products you use.

PRAZOSIN OVERDOSE

Symptoms of an overdose include: low blood pressure (hypotension).

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of prazosin or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.

MISSED DOSE

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

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Source: Selected from data included with permission and copyrighted by Boots UK Limited or TicTac Communications Ltd. This copyrighted material is sourced from a licensed data provider and is not for distribution, except as may be authorised by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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