Pro-Guanfacine XR: Uses, Side Effects and Dosage

What PRO-GUANFACINE XR is used for:

• PRO-GUANFACINE XR is used to treat Attention Deficit Hyperactivity Disorder (ADHD) in children and adolescents 6 to 17 years of age. It can be used alone or with another medicine called a psychostimulant.

  PRO-GUANFACINE XR may be a part of your/your child’s overall treatment plan for ADHD. The healthcare professional may also recommend counselling or other therapy.

How PRO-GUANFACINE XR work:

PRO-GUANFACINE XR contains the medicinal ingredient guanfacine. Guanfacine is not a central nervous system (CNS) stimulant. The exact way guanfacine works to treat ADHD in not known. PRO-GUANFACINE XR is thought to affect receptors (alpha_2A-adrenergic receptors) in the brain to reduce nerve impulses. This helps increase attention (including the ability to follow and finish tasks) and decrease impulsiveness and hyperactivity in patients with ADHD.

The ingredients in PRO-GUANFACINE XR are:

Medicinal ingredient: guanfacine (as guanfacine hydrochloride)

Non-medicinal ingredients: Anhydrous Lactose, colloidal silicon dioxide, fumaric acid, hypromellose, indigotine aluminium lake, magnesium stearate, and yellow ferric oxide.

PRO-GUANFACINE XR comes in the following dosage forms:

Tablets; 1 mg, 2 mg, 3 mg, and 4 mg

Do not use PRO-GUANFACINE XR if:

• you/your child are/is allergic to guanfacine or any other non-medicinal ingredients in PRO-GUANFACINE XR (see The ingredients in PRO-GUANFACINE XR are:)

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take

PRO-GUANFACINE XR. Talk about any health conditions or problems you may have, including if you or your child:

• has a heart problem such as:

  • a very slow heart rate (pulse)
  • a heart rhythm problem (arrhythmia)
  • heart disease
  • congestive heart failure
  • a hereditary disorder of the heart’s electrical system (called congenital long QT syndrome)
• has fainted in the past (or has a history of fainting)
• has low or high blood pressure
• has liver or kidney problems
• have mental health problems or a family history of mental health problems including psychosis, mania, bipolar illness, depression, or suicide
• has any other medical condition

• is pregnant. Your healthcare professional will decide if you can take this medicine if you are pregnant.

• is breastfeeding or plans to breastfeed. It is not known if PRO-GUANFACINE XR passes into breast milk.

Other warnings you should know about:

The following have been reported with use of medicines used to treat ADHD such as PRO-GUANFACINE XR:

Mental Health problems (psychiatric):

Suicidal behaviour and thoughts: New or worsening thoughts or feelings related to:

• thoughts about suicide (thinking about or feeling like killing yourself)
• suicide actions (a suicide attempt or completed suicide)

Suicidal thoughts or behaviours may occur at any time during treatment, particularly:

• when you or your child starts treatment
• when there is a change to the dose
• after you or your child stops taking PRO-GUANFACINE XR

Should this happen to you or your child, talk to your healthcare professional right away.

Bipolar Disorder: New or worsening bipolar illness (extreme mood swings with periods of mania (unusually excited, over-active or un-inhibited) alternating with periods of depression (feelings of sadness, worthlessness or hopelessness). Tell your/your child’s healthcare professional about:

• any mental health problems you or your child has
• family history of suicide, bipolar disorder or depression

Psychotic or Manic Symptoms: New or worsening of psychotic or manic symptoms can occur when taking PRO-GUANFACINE XR at usual doses. Symptoms can include:

• hallucinations (hearing voices, believing things that are not true or feeling suspicious)
• feeling unusually excited, over-active or un-inhibited

Call your healthcare professional right away if you or your child has any new or worsening mental health symptoms while taking PRO-GUANFACINE XR, especially seeing or hearing things that are not real, believing things that are not real, or you start feeling suspicious.

Aggressive behaviour: New or worse aggressive behaviour, hostility can occur.

These new or worsening mental health problems may be more likely to occur if your child has mental disorders that you may or may not have known about.

Feeling sleepy/drowsy: PRO-GUANFACINE XR can make you or your child feel sleepy and drowsy. Avoid doing tasks that require special attention such as riding a bike, driving/operating machinery or doing other dangerous activities until you know how PRO-GUANFACINE XR affects you or your child. If you notice you or your child is feeling sleepy or drowsy often, talk to your healthcare professional.

Do NOT take PRO-GUANFACINE XR with alcohol or other medicines that make you or your child feel sleepy or drowsy. This can make it worse.

Dehydration: While on PRO-GUANFACINE XR, you/your child should avoid becoming dehydrated or overheated.

Weight: Talk to your/your child’s healthcare professional about any problem with weight while taking PRO-GUANFACINE XR.

Monitoring: Your/your child’s healthcare professional should monitor your/your child’s heart rate and blood pressure before starting treatment, periodically during treatment, when the dose is changed and after stopping treatment.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with PRO-GUANFACINE XR:

• ketoconazole (used to treat yeast or fungal infections)
• rifampin (used to treat tuberculosis (TB))
• valproic acid (used to treat bipolar disorder)
• medicines that can lower your heart rate, such as antiarrhythmics and beta blockers
• medicines used to treat chest pain (angina)
• medicines used to treat high blood pressure
• medicines that can cause QT prolongation
• medicines that can increase your risk of fainting
• medicines that cause sleepiness (sedatives)
• medicines inducing sleep in surgical anesthesia or in the treatment of insomnia (hypnotics)
• medicines used as tranquilizer (benzodiazepines)
• medicines used as central nervous system depressants (barbiturates)
• medicines used to treat psychosis (antipsychotics) • other medicines for ADHD (such as methylphenidate, lisdexamfetamine dimesylate)
• any medicine that may cause heart valve problems
• alcohol
• grapefruit, grapefruit juice or products containing grapefruit extract

How to take PRO-GUANFACINE XR:

• Take/give PRO-GUANFACINE XR exactly as your/your child’s healthcare professional has told you.
• Take/give PRO-GUANFACINE XR once a day, either alone or with an ADHD psychostimulant medication prescribed by your/your child’s healthcare professional. Your healthcare professional will tell you when you/your child should take PRO-GUANFACINE XR and when to take the other ADHD psychostimulant medication.

• Swallow the tablet whole with a small amount of liquid. Do NOT crush, chew or break the tablet before swallowing and do NOT take it with a high-fat meal.

• Do NOT stop taking PRO-GUANFACINE XR or giving it to your child without talking to your healthcare professional. Stopping this medication suddenly may lead to a serious increase in blood pressure and heart rate. Your healthcare professional will decrease the dose slowly over time to avoid side effects. This is especially important if you/your child are taking a psychostimulant along with PRO-GUANFACINE XR.

Usual dose:

Usual child and adolescent (6 to 17 years of age) dose: The recommended starting dose is 1 mg tablet once a day. Your healthcare professional may change the dose until it is right for you/your child.

Overdose:

Possible symptoms of an overdose include:

• low blood pressure
• initial high blood pressure
• slowing of heart rhythm
• trouble breathing
• feeling tired/having low energy

Missed Dose:

• If you miss two or more doses in a row, talk to your healthcare professional or your child’s healthcare professional. Your healthcare professional may need to restart you/your child on a lower dose.

Possible side effects from using PRO-GUANFACINE XR:

These are not all the possible side effects you may have when taking PRO-GUANFACINE XR. If you experience any side effects not listed here, tell your healthcare professional.

Side effects may include:

• Feeling sleepy, trouble sleeping
• Feeling tired
• Feeling dizzy
• Headache
• Nausea
• Stomach pain
• Not feeling hungry (decreased appetite)
• Feeling drowsy
• Dry mouth
• Constipation

Serious side effects and what to do about them

drug and get immediate

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting side effects

Storage:

Store at room temperature 15°C to 30°C.

Keep out of reach and sight of children.

If you want more information about PRO-GUANFACINE XR:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug- products/drug-product-database.html or by contacting Pro Doc Ltée at 1-800-361-8559, www.prodoc.qc.ca or medinfo@prodoc.qc.ca