Guanfacine review 2018- Benefits & Side Effects (Updated July 2019)

Guanfacine Product Review

Guanfacine is a type of medication used (alone or in combination with other medication) to treat high blood pressure. High blood pressure is a condition that mostly affects the functionality of the heart and arteries. If not treated, it can cause damage to the blood vessels of the heart, brain, kidney and other parts of the body leading to stroke, heart failure, kidney failure or even loss of vision. High blood pressure can also increase the risk of experiencing heart attacks. Guanfacine helps controls the blood pressure thus reducing the occurrence of these problems. The medication is an alpha agonist. It works by controlling nerve impulses along the major nerve pathways, which relaxes blood vessels for smooth flow of blood in the body.

Guanfacine extended-release tablets can also be prescribed, alone or with other medications, for patients suffering from attention deficit hyperactivity disorder (ADHD). The condition is usually characterized by difficulty in focusing, remaining still or quiet or controlling actions, especially among children and adolescents. The medication works by increasing attention and/or decreasing restlessness, distraction, and impulsiveness. Guanfacine is used as a major part of a treatment program that includes social, psychological and educational treatment.

How Guanfacine Should Be Used

Guanfacine comes in two forms: as a tablet and as an extended-release tablet. All these forms of medications are taken by mouth. The Guanfacine tablet is usually taken once a day when going to bed while the extended-release tablet is taken once a day but the patient is not required to take a high-fat meal. Doctors recommend patients to take Guanfacine about the same time every day. All the directions provided on the prescription label should be followed to the latter and in case of any problem or misunderstanding; the patient should contact a professional doctor or pharmacist.

Extended-release tablets should be swallowed whole with a small amount of water or liquid. It is not advisable for the patient to break, chew or crush the tablets. Usually, the doctor will prescribe a low-dose guanfacine and may increase the dose gradually. For extended-release tablets, the doctor might increase a dose once a week and not more than once in every 3 to 4 weeks for those taking tablets.

Guanfacine tablets and extended-release tablets are meant for controlling the patient’s condition and not curing it. A patient might take up to 2 weeks to experience the benefits of the medication, upon the first dosage. Guanfacine should be taken continuously as per the prescribed dose as stopping to take the medication might increase the blood pressure, anxiety or nervousness.

Special Precautions before Using Guanfacine

Before using guanfacine ensure you do the following:

-Let your doctor or pharmacist know if you’re allergic to guanfacine or any of the ingredients included in the tablets or extended-release tablets.

-Don’t take guanfacine tablets and extended-release tablets at the same time unless guided by doctor’s advice

-Let your doctor know about any prescription or non-prescription medication or dietary supplements you’re currently taking. Be sure to mention to your doctor any of the following medications: antidepressants, barbiturates like Phenobarbital (luminal); antihistamines; clarithromycin(Biaxin);carbamazepine( Epitol, Carbatrol, Tegretol, Equetro); itraconazole(Sporanox, Onmel);ketoconazole(Nizoral): medications for high blood pressure, anxiety, seizures, mental illness or nausea; phenytoin (phenytek, Dilantin); nelfinavir(Viracept); rifabutin(Mycobutin); sedatives; tranquilizers; sleeping pills; and valproic acid(Depakene). Telling your doctor the medication you’re taking or planning to take will help him change your doses or monitor the side effects.

-Tell your doctor of your history or any recent cases of fainting, heart attack, stroke or low blood pressure; a slow heart rate; heart disease, kidney disease or liver disease. Be sure to also disclose any details of bipolar disorder if any. Bipolar or manic-depressive disorder is a condition characterized by episodes of depression, mania and/or other abnormal moods.

-let your doctor know if you’re pregnant, breastfeeding or planning to become pregnant

-If you’re having any form of surgery, it’s important to inform the surgeon or concerned doctor that you are using guanfacine

-Seek advice from your doctor about the safe use of alcoholic beverages, especially when you’re beginning your guanfacine dose.

-You should know that guanfacine treatment may cause fainting due to dehydration or overheating of the body.

-You need to understand that guanfacine may cause such side effects as dizziness, fainting or lightheadedness, especially when you are taking the medication for the first time. To avoid these effects, it’s advisable that you get out of bed slowly as you rest your feet on the floor for some time before standing up.

-Know that guanfacine should be used in the total ADHD treatment program which includes special counseling and education.

Key Things to Check On Before Taking Guanfacine 

  • Pediatric 

Numerous studies have indicated a significant relationship between guanfacine tablets effects and age. Children under 12 years may experience some side effects from use of eh medicine. Hence safety and efficacy needs to be checked with a healthcare professional before administering a dose of guanfacine extended-release tablets to children.

  • Pregnancy and Breastfeeding 

Pregnant women (regardless of the trimester) may use guanfacine under the doctor or pharmacists prescription. Though there’re no confirmed side effects to the fetus, it is important to ask for expert advice on the right dosage to take on.

There may be minimal or no side effects of guanfacine on a breastfeeding child. Before taking on a given dose, it may be important to eight of the potential benefits of the medication against the potential risks on breastfeeding.

  • Suicidal Ideation

Patients who have been diagnosed with emergent suicidal behavior or ideation during ADHD treatment should be thoroughly evaluated by their physician or doctor before administering guanfacine. Treatment of any underlying psychiatric conditions might be necessary with major consideration on changing the entire ADHD treatment program.

  • Alcohol and Tobacco Interactions

Using alcohol and/or tobacco during guanfacine medication (when used alone or combined with other medications) may cause interactions to occur. For safety and efficacy of the medication, you might need to talk to your doctor to get advice on the best way to reduce or stop the use of these drugs.

Are There Any Dietary Instructions That A Patient Should Follow When Using Guanfacine?

Before getting a guanfacine prescription from your doctor, be sure to talk with him or her about eating grapefruits or drinking grapefruit juice. However, you might be required to make dietary and lifestyle changes so as to help control the body’s blood pressure. Patients on guanfacine prescription are required to adhere to a diet low in fat and salt, maintain a healthy weight, exercise for at least 30 minutes daily and avoid smoking cigarette and moderate alcohol consumption.

Guanfacine Dosing

The amount of guanfacine dosage prescribed is different for different patients. It is always important for patients to follow the orders or directions provided on the label. Each dose is administered based on the type and severity of the condition. Also, the amount of medicine a patient is given will depend on the strength of the medication. However, there are general guidelines on dosage with recommended time in-between doses, and length of time the medication should be taken based on the medical problem. Here is the average amount of dose you can expect for the following medications:

Extended-release Tablets for ADHD: adolescents and children aged 6 years and above should take 1 milligram (mg) of the medication, once a day; the medication can be taken in the morning or evening but it should be the same time each day. The doctor may gradually adjust the dosage if necessary. However, the dosage cannot exceed 4 mg per day. Children aged below 6 years must receive a proper determination from the doctor before they can use any of these medications.

Prior to prescribing, the doctor may need to conduct a baseline evaluation to help identify patients with increased risk of sedation, somnolence, hypotension and/or bradycardia. Other important aspects that may need to be evaluated include weight increase or the risk of obesity. Evaluating and documenting a patient’s blood pressure and/or heart rate can provide a clear platform for proper prescription.

Oral Dosage Tablets for High Blood Pressure: Adults are required to take 1 milligram (mg) of guanfacine per day, at bedtime. The doctor might increase the dose up to 3 mg/day if necessary. Children that require this dose must consult the doctor to determine their case.

Guanfacine is cleared by the liver and kidneys, with about 30 percent of the medicinal product being excreted in urine. Thus for patients suffering from renal impairment, there might be a need for dose reduction to ensure the effectiveness of medication and reduced side effects. Regardless of the age of the patient, it’s important for the doctor to evaluate conditions relating to liver and kidneys before administering the medication.

Effects of the Medications on the Height, Weight, and Body Mass Index (BMI)

Adolescents and children treated with extended-release tablets (Intuniv) may show an increase in BMI. Therefore, you should monitor your height, weight and BMI prior to the initiation of the therapy. You can also keep track of your BMI after every 3 months for the first year you’re under medication while taking into consideration clinical judgment. As your dose administration changes, you should change your evaluation time intervals.


If you miss a guanfacine medication dose, you should take it as soon as you remember. However, if it’s almost time for the next dose, you can skip the missed dose and continue with your regular dosing schedule. Never double the doses as that might cause adverse side effects.

If you forgot or missed taking the extended-release tablets for two or more days, it is necessary to consult your doctor. Suddenly cutting off your body form medication can cause unwanted effects. So checking with the doctor might help you answer the more pressing questions.

What Are The Possible Side Effects Of Guanfacine?

Guanfacine may have side effects to patients, which might manifest the symptoms upon the first or subsequent doses. Here are some of the common side effects experienced by patients taking guanfacine tablets or extended-release tablets:

  • Dry mouth
  • Fatigue
  • A headache
  • Irritability
  • Decreased appetite
  • Decreased sexual ability
  • Stomach pain
  • Vomiting
  • Constipation
  • Nausea
  • Some of the more serious side effects may include:
  • Fainting
  • Blurred vision
  • Skin Rashes
  • Slow heart rate


What Are The Symptoms Of Overdose? 

Taking an overdose of the guanfacine medication may result in dizziness or unusual weakness or tiredness. Some of these effects may last for some time and might go away during treatment as the body adjusts to the medication. It is always important to contact a healthcare professional to advice on ways or preventing or reducing some of the side effects. In case of an emergency, you can also call your local poison control center for assistance if the victim or patient collapses or stops breathing abruptly.


Guanfacine should be stored in a closed container at room temperature and away from heat, moisture, and direct sunlight. The medication should also be kept away from freezing. Always keep it out of reach of children.

Do not keep any expired medication in your home

In case of any questions on safe disposal, contact a healthcare professional for advice

Where Can You Get The Best Guanfacine Medications?

Guanfacine tablets and extended-release tablets are available both in online and local registered pharmacies and clinics. Patients can also get prescriptions from either private or public hospitals. It’s always important to consider getting these forms of medication from licensed and qualified professional doctors and pharmacists so as to be assured of getting the right prescription. Always do your research to ensure you’re buying the medication from the right professional healthcare provider.

Conclusion Guanfacine?

Upon prescription, you should remember to keep all the appointments with your medical doctor or pharmacist. That’s to ensure to undergo regular check-up for your blood pressure and heart rate in order to determine the response of guanfacine to your condition.

Never share or allow anyone else to take your prescribed guanfacine dose. In case you have any questions about refilling your prescription, it’s important to consult or ask your pharmacist.

Always keep a written list of all the prescription and over-the-counter medicines you’re taking. Also be sure to include such products as vitamins, minerals or any other dietary supplements you’re taking. Bring the list along every time you visit your doctor or whenever you’re admitted to a hospital. That can provide great information that can be used in treating you in case of any medical emergency.



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