Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
HEALTH CANADA ADVISORY
[March 30, 2015]
Health Canada has issued new restrictions concerning the use of drugs used in the management of Attention Deficit Hyperactivity Disorder (ADHD). To read the full Health Canada Advisory, visit Health Canada's web site at www.hc-sc.gc.ca.
Abnormal heart rhythms: Guanfacine can cause abnormal heart rhythms. Certain medications (e.g., sotalol, quinidine, chlorpromazine, pimozide, gatifloxacin, moxifloxacin, mefloquine, pentamidine, dolasetron mesylate, probucol, tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should not be used in combination with this medication. If you have been told that your child is at an increased risk of developing an abnormal heart rhythm, discuss with your doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Drowsiness and reduced alertness: Guanfacine may affect the mental or physical abilities needed to perform tasks that require special attention. Have your child avoid riding a bike, operating machinery, or performing other hazardous tasks until you have determined how this medication affects your child.
Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If your child has reduced kidney function or kidney disease, discuss with your doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If your child has liver problems, discuss with their doctor how this medication may affect their medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Psychiatric and behavioural concerns: Medications used to treat ADHD, including guanfacine, may increase symptoms of mental illnesses such as bipolar disorder, psychosis, or depression. This medication may cause people to feel agitated (restless, anxious, aggressive, emotional) and not like themselves. If you experience these side effects or notice them in a family member who is taking this medication, contact your doctor immediately. Your child should be closely monitored by your doctor for emotional and behaviour changes while taking this medication.
Self-harm and suicide risk: People with ADHD may have a slightly increased risk of suicidal thoughts and behaviours. Like other medications for ADHD, guanfacine may contribute to this risk. It is important to watch for suicidal thoughts and behaviors and encourage your child to report any worrisome thoughts or feelings to you. Report any concerns to your child's doctor immediately.
Stopping the medication: If this medication needs to be stopped, it should be done gradually, under the supervision of your doctor. Suddenly stopping guanfacine can cause increased blood pressure and heart rate, which may be of concern to some people.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if guanfacine passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children less than 6 years old. The effectiveness of using this medication to treat ADHD has not been established for adolescents more than 13 years old.