“Clonidine [Kapvay] can cause severe depression and is particularly dangerous for anyone with a history of depression.” (4)
Kapvay Side Effects and Warnings
- Brand Names: KAPVAY (tablets)
- Generic Name: clonidine hydrochloride
- Categories: CENTRAL ALPHA-2 AGONIST
- and ANTI-HYPERTENSIVE
How Kapvay Works
Kapvay reduces blood flow in the brain and produces dose-related sedation. (5) The drug lowers blood pressure and heart rate, thereby supressing the body's “fight or flight response” by decreasing that activity of part of the brain known as vasomotor center. Users of clonidine experience typical drowsiness. (1,2)
- High blood pressure
- Attention deficit disorder
- Narcotic withdrawal syndrome (off-label)
Do Not Use If
- You have a history of depression. Kapvay can cause severe depression and is particularly dangerous for anyone with a history of depression. (4)
- You have heart disease, unless your doctor tells you it is okay. (6)
- You have a problem in your heart that impacts the timing of the heartbeat or transmission of electrical impulses through the heart. (3)
- You previously had an allergic reaction to clonidine. (3)
DO NOT SKIP A DOSE OR STOP SUDDENLY
Serious Risks Include ACUTE WITHDRAWAL SYMPTOMS (rebound hypertension) with abrupt discontinuation.
Severe cases can result in a very large increase in blood pressure which requires prompt treatment to avoid complications such as organ damage.
ABOVE: Rybacki, J., et al. The Essential Guide to Prescription Drugs, HarperCollins Publishers Inc., NY (1996).
Let Your Doctor Know Before Taking This Drug If
- you have or have had serious emotional depression
- you are taking any antidepressant
- you are taking a tricyclic antidepressant
- you are taking any sedative
- you are taking any hypnotic drugs
- you have a circulatory disorder of the brain
- you have angina or coronary heart disease
- you have a very slow heart rate
- you have Buerger's disease (hands or feet may be pale, red, or bluish and may feel cold;
caused by inflammation of blood vessels)
- you have Raynaud's phenomenon (cold temperatures or strong emotions cause blood vessel spasms that block blood flow to the fingers, toes, ears, and nose)
- you plan to have surgery under general anesthesia in the near future
“Clonidine (Kapvay) can also cause severe depression and is particularly dangerous for anyone with a history of depression.”
ABOVE: Wolfe, S.M. et al. “Worst Pills Best Pills,” Public Citizen Health Research Group, Washington DC (1988).
Common (Expected) Side Effects
- Lowering of blood pressure (expected)
- Lowering of heart rate (expected)
- Drowsiness and Sedation (sleepiness) (33-35%)
- Dry Nose and Mouth (40%)
- Headache (19-29%)
- Constipation (10%)
- Upper Abdominal Pain (13-20%)
- Fatigue (13-16%)
- Dizziness (16%)
- Change in mood
- Trouble sleeping (insomnia)
- Light-headedness (caused by lowering of blood pressure)
- Sore throat
- Dry eyes (in patients who wear contact lenses)
Possible Adverse Effects
If any of the following develop, consult your physician promptly for guidance.
Mild Adverse Effects
- Allergic Reactions: Skin rash, hives, localized swellings, itching
- Headache, dizziness, fatigue, anxiety, nervousness, dryness and burning eyes
- Painful parotid (salivary) gland, nausea, vomiting
- Weight gain, urinary retention
- Dry mouth
- Urination at night
- Thinning of hair (rare)
Serious Adverse Effects
- Raynaud's phenomenon (cold temperatures or strong emotions cause blood vessel spasms that block blood flow to the fingers, toes, ears, and nose)
- Aggravation of congestive heart failur, heart rhythm disorders, vivid dreaming, nightmares, depression, hallucinations
- Sleep disorders
- Corneal ulcers (rare)
- Acute pancreatitis (rare)
- Slow heart beat (bradycardia)
Possible Effects On Sexual Functions
- Decreased libido (10%)
- Impotence (8-24%)
- Impaired Ejaculation (rare)
- Enlargement of male breasts
- Precocious puberty in females (puberty at an early age)
- Do not stop this drug suddenly! Sudden withdrawal can cause a severe and possibly fatal reaction.
- Hot weather or fever can reduce blood pressure significantly. Dose adjustments may be necessary.
- Report the development of any tendency to emotional depression.
“The main problem with clonidine is that missing one or two doses can have serious effects, including sweating, tremor, flushing, and severe high blood pressure.”
ABOVE: Wolf, S., et al. Worst Pills Best Pills, Public Citizen Health Research Group, Washington DC (1988).
Overdose Side Effects
- Marked drowsiness
- Dry mouth
- Slow pulse
- Low blood pressure
- Stupor progressing to coma
“Clonidine is among the most commonly prescribed drugs to treat insomnia for children with ADHD... However, the American Academy of Sleep Medicine advises first trying behavioral strategies for pediatric insomnia and using medication sparingly. Consumer Reports medical advisors urge people to avoid taking medication to treat the side effects of another drug unless that drug is essential.”
ABOVE: American Society of Health-System Pharmacists. Off-label use of clonidine: Is it really a wonder drug?; Consumer Reports, Consumers Union of US, Inc. (updated 9/2009).
The use of clonidine and methylphenidate in combination continues to be controversial. Both drugs can adversely affect an irregular heart rate or rhythm (cardiac arrhythmia) and this effect can be worsened when the drugs are combined. Four deaths of children using both drugs were reported to the FDA.
ABOVE: Cantwell D.P., Swanson J., Connor D.F. “Case study: adverse response to clonidine.” J Am Acad Child Adolesc Psychiatry 1997;36:539-44.