Drug Interactions With Guanfacine ER
More Information on Drug Interactions With Guanfacine ERThe following sections explain in detail the potentially negative interactions that can occur when guanfacine ER is combined with any of the drugs listed above.
Alcohol or Medications That Cause Drowsiness
Combining guanfacine ER with alcohol or medications that cause drowsiness can lead to undesirable or even potentially dangerous side effects, such as extreme drowsiness, "passing out," or confusion. Check with your healthcare provider before taking such medications together. People should not drink alcohol while taking guanfacine ER.
Blood Pressure Medications
Taking guanfacine ER with a high blood pressure medication might increase the risk of low blood pressure. Be sure to watch for signs of this problem, such as lightheadedness, dizziness, or fainting.
Guanfacine ER should not be combined with short-acting guanfacine (Tenex®), since guanfacine ER is a longer-acting version of the same active ingredient.
Guanfacine ER is metabolized by a specific liver enzyme known as CYP3A4. Some other medications (known as CYP3A4 inhibitors) slow down the activity of this enzyme, causing an increase in the level of guanfacine ER in the blood. This could potentially lead to serious side effects. Check with your healthcare provider before taking these medications together.
Guanfacine ER may increase the level of valproate medications in the bloodstream. In order to avoid this drug interaction, your healthcare provider may want to measure the level of valproic acid in your blood and may need to adjust the dose of your valproate medication.
Final ThoughtsIt is possible that not all guanfacine ER drug interactions were discussed in this article. Therefore, you should talk with your pharmacist or healthcare provider about any specific interactions that may apply to you.