ADHD Home > Kapvay Side Effects
Possible reactions to Kapvay include headaches, drowsiness, and irritability. In most cases, people can take this medication without any problems. However, contact your healthcare provider if you develop serious side effects while taking Kapvay, such as extreme drowsiness, fainting, or difficulty breathing. Even if the reaction is unrelated to the medication, your healthcare provider can help diagnose and treat the problem.
An Introduction to Kapvay Side EffectsJust like any medicine, Kapvay™ (clonidine ER) can cause side effects. However, not everyone who takes the medication will have problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are treated easily by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with Kapvay. Your healthcare provider can discuss a more complete list with you.)
Common Side Effects of KapvayKapvay has been studied extensively in clinical trials. In these studies, one group of people received Kapvay, while another group was given a placebo (a "sugar pill" that does not contain any active ingredients). As a result, it was possible to see what side effects occurred, how often they appeared, and how they compared to the placebo.
Some studies combined Kapvay with a stimulant medication (such as Ritalin®); the information in this article does not include side-effect data from such trials, as it is difficult to know how much each medication contributed to the side effects.
In clinical studies, the most common side effects of Kapvay included:
- Drowsiness -- in up to 31 percent of people
- Headaches -- up to 29 percent
- Upper abdominal pain (stomach pain) -- up to 20 percent
- Fatigue -- up to 16 percent
- Upper respiratory tract infections (such as the common cold) -- up to 11 percent
- Irritability -- up to 9 percent
- Nightmares -- up to 9 percent
- Dizziness -- up to 7 percent
- A gastrointestinal virus (the so-called "stomach flu") -- up to 7 percent
- Throat pain -- up to 6 percent
- Nausea -- up to 6 percent.
Other common Kapvay side effects, occurring in 3 to 6 percent of people, included but were not limited to:
- Emotional problems
- Dry mouth
- Nasal congestion
- Increased body temperature
- Ear pain
- Abnormal sleep
- A slow heart rate or a fast heart rate
- Frequent daytime urination
- Flu-like sickness
- Shakiness (tremors)
- Sleep terrors.