Clonidine Uses And Mechanism Of Action: How It Works

Last Updated: March 16, 2020

Authored by Isaak Stotts, LP

Clonidine is used for curing a range of health issues, mainly connected with hypertension, mental disorders, hot flashes, and smoothing the treatment of different withdrawals. This article is aimed to determine the main reasons how this drug can positively influence the patient’s health during clonidine uses, highlight contraindications, and discuss the mechanism of action.

Catapres FDA-Approved Uses

Clonidine For High Blood Pressure

Catapres is a kind of drug that helps to decrease high blood pressure and heart rate by relaxing the arteries and stimulate the blood supply to the heart. Catapres drug class belongs to centrally acting alpha-agonist hypotensive agents. Сlonidine HCl uses have the ability to reduce tone in the sympathetic section of the central nervous system. It leads to an effective decrease in pressure on the vascular walls, changing the total vascular resistance of the vessels. As a result, the number of myocardial contractions and the volume of cardiac output are effectively reduced.

This drug can also influence the peripheral blood vessels. That is why when the patient starts to use this medicine it can cause a rise in pressure for a short period of time. At the same time, Catapres helps to reduce intraocular pressure, performing a sedative and analgesic effect.

clonidine for ADHD

Clonidine For ADHD

Clonidine for kids with ADHD helps to reduce hyperactive symptoms, as well as to cope with accompanying sleep disturbances. According to the investigation made among children (4-12 y.o) and adolescents (13-17 y.o.), clonidine use for a period of more than one year has shown a positive response. The results didn’t have a significant difference whether patients took a drug exclusively at bedtime or during a day, as well as in weight-corrected doses. Only 31% of patients had adverse effects during medical therapy.

Clonidine For Tics

Clonidine for kids with Tourette’s syndrome helps to decrease the severity and intensity of tics. Catapres works by acting on a different chemical system to dopamine by stimulating adrenaline receptors in the brain.

Clonidine For Pain

Catapres indications include not only postoperative treatment for improving surgical outcomes (as the medicine provides analgesic effects) but also for the prevention of neuropathic or chronic pain and as an adjunct therapy for cancer-related pain. The drug acts not only locally, at the place of injury, but influences the central nervous system. The use of clonidine as a topical remedy may give partial pain relief, not for all people with painful diabetic neuropathy.

Clonidine Off-Label Uses

Apart from FDA-approved uses of the medication, there are several clonidine off-label uses. The indications include treatment and management of anxiety, sleep disorders, including insomnia, withdrawal symptoms from opioids, benzodiazepines, and alcohol, PTSD, etc.

Clonidine For Anxiety

Patients obtained panic-free status during the usage of Catapres for anxiety can feel lowered anxiety levels and better functioning. Usually, the prescribed clonidine dosage for anxiety is 0.1 mg twice a day. Among the reasons why it is widely used to treat anxiety is because one of its main mechanisms of action targets and suppresses the fight-or-flight centers of the brain. What is more, it causes less dependency than other anti-anxiety medications.

clonidine for sleep

Clonidine For Sleep

Nowadays, clonidine use for sleep problems is usually prescribed in case of insomnia or sleep disturbances, including night awakening, associated with attention-deficit hyperactivity disorder (ADHD) or autistic spectrum disorders. The effectiveness of clonidine for insomnia and improving sleep patterns in children and adolescents experiencing ADHD can be explained by the medicine’s sedative properties and its impact on the reduction of nighttime ADHD symptoms.

Clonidine For Withdrawal

Clonidine use has a strong effect to inhibit sympathetic outflow, that is why it is usually prescribed to use clonidine for opiate withdrawal. Since pheochromocytomas are not under neurologic control, Catapres has been used successfully to differentiate the presence of these tumors from other hypertension-associated disease states. The router of medication administration may vary, but patients should never try snorting clonidine.

It is important to say that Catapres is not a narcotic and does not reduce drug craving. However, clonidine helps with opiate withdrawal, usually under close medical monitoring.

Clonidine for alcohol withdrawal is also an effective remedy. According to the research, the medication helps alcoholics in withdrawal and includes minor side effects (mild sedation). For treating alcohol withdrawal, it could be prescribed to use Catapres in combination with benzodiazepine tranquilizers such as Librium, Valium, or Xanax.

Clonidine For Hot Flashes

Clonidine is used to treat hot flashes associated with menopause when hormone replacement therapy is not needed or not desired. For those who have sweat and hot skin surges, the medicine works by helping to slow the reaction of the blood vessels to stimuli that cause them to narrow and widen.

Clonidine For Autism

Children with autism spectrum disorders are used to having sleep and behavioral problems. Clonidine use for kids is an efficient drug to cope with impulsivity, inattention, and hyperactivity, usually used as a sedative substance for medical procedures.

clonidine and PTSD

Clonidine For PTSD

Posttraumatic stress disorder is a psychiatric disease that can occur after catastrophic stress. Doctors often prescribe clonidine for nightmares associated with PTSD. The use of clonidine can help to low the anxiety level and reduce the outbursts of rage that helps to stabilize and smooth the sleeping.

Clonidine For Restless Legs

Clonidine use may be an effective treatment for restless leg syndrome patients who don’t have large numbers of sleep-disrupting periodic limb movements but have delayed sleep onset due to leg sensations and subsequent motor restlessness.

Clonidine For Sweating

Because emotional sweating is under sympathetic control, the drug could be useful in the treatment of excessive emotional sweating. Catapres has been helpful in patients with hyperhidrosis, especially in those whose condition is caused by antidepressants. It can be quite sedating at the doses necessary and should not be stopped suddenly.

Clonidine Suppression Test

Сlonidine suppression test is often used to diagnose the pheochromocytoma (tumor of adrenal gland tissue). This method is a useful adjunctive test to rule out pheochromocytoma in hypertensive patients with suggestive symptoms and boundary catecholamine values. The patient should be supervised by a doctor during the whole test.

Сlonidine suppression test includes the following steps:

  • Put the patient in a quiet and darkened room to make the patient feel relaxed.
  • Insert a venous cannula into the arm.
  • Document pulse and blood pressure three times every 5 minutes, and every 30 minutes thereafter.
  • After 30 minutes, take blood for baseline catecholamines and metanephrines (Lithium heparin and EDTA tubes). Repeat after 5 minutes.
  • Give the patient 0.3mg clonidine hydrochloride to administer orally.
  • Continue checking pulse and blood pressure every 30 minutes, as hypotension typically occurs.
  • Take samples of blood for catecholamines and metanephrines at 60, 120, and 180 minutes.
  • Monitor the patient’s condition every 30 minutes until their blood pressure normalizes, and the patient feels fully recovered.
  • Remove a venous cannula at the end of the test.

when to take clonidine

When To Take Clonidine

Uses for clonidine should be appointed by a doctor, but it is typically prescribed to be taken early in the morning and before sleep. If it is needed to take different doses during a day, it is better to take a higher dose later at bedtime. Catapres can be taken during mealtime or separately, it does not reflect on the result.

Clonidine Mechanism Of Action

How Long Does It Take For Clonidine To Take Effect?

There are immediate-release (IR) and extended-release (ER) formulations of this medicine. Clonidine brand names are Catapres (ER) and Kapvay (IR), among others. It is not recommended to take clonidine for children of immediate-release type. The peak plasma concentrations after oral IR administration is reached in approximately 1 to 5 hours.

The second type (ER) is also not recommended to use for children under 6 years old. The peak clonidine concentrations were approximately 50% of those achieved with the IR formulation and occurred approximately 5 hours later. And total systemic bioavailability after the ER formulation was approximately 89% of that after the IR formulation.

Typically, the drug is taken for 2 weeks before a visible result. Also, it can be prescribed for a longer period, for example, 2-4 months to see the benefits of the clonidine use. The maximum outcome can be seen after 4-8 weeks.

How Long Does Clonidine Last?

The drug is quickly absorbed, and the peak effects are seen within 1-3 hours. Clonidine MOA has the blood pressure-lowering effect that happens within 30-60 minutes after an oral dose, and the maximal effect on blood pressure occurs within 2-4 hours.

warnings and contraindications of clonidine

Warnings & Contraindications

  • People with heart problems may obtain more severe conditions with blood pressure and heart rate issues if they have low indicators in daily life.
  • Women who are breastfeeding have to consult with a doctor to figure out whether not to breastfeed or not to take the drug, as Catapres uses may cause side effects in a breastfed child.
  • People with orthostatic hypotension need to control the level of organism hydration during the Catapres uses. In addition, they can feel dizziness in case they stand up rapidly.
  • People with eye issues can feel the discomfort when they wear contact lenses and have focusing problems.

How To Treat Catapres Misuse

Catapres abuse can strongly affect blood pressure or cause a rapid decrease in heart rate. In large doses, it can also cause deep sedation and harden a respiratory function. The drug should be taken in the dosage prescribed by a doctor. Excessive use of Catapres can be harmful and cause additional health problems, so the best way to avoid the adverse effects of the drug is to follow the instructions.

In case of specific side effects and life-threatening conditions, patients should seek help in the drug rehabilitation facilities. Such centers are designed to provide a full spectrum of the required addiction treatment.

Page Sources

  1. Prince JB, Wilens TE, Biederman J, Spencer TJ, Wozniak JR. Clonidine for sleep disturbances associated with attention-deficit hyperactivity disorder: a systematic chart review of 62 cases. Journal of the American Academy of Child and Adolescent Psychiatry. 1996; 35(5): 599–605. doi:10.1097/00004583-199605000-00014.
  2. Eddy CM, Rickards HE, Cavanna AE. Treatment strategies for tics in Tourette syndrome. Therapeutic Advances in Neurological Disorders. 2011; 4(1): 25–45. doi:10.1177/1756285610390261.
  3. Neil MJ. Clonidine: clinical pharmacology and therapeutic use in pain management. Current Clinical Pharmacology. 2011; 6(4): 280–287. doi:10.2174/157488411798375886.
  4. Wrzosek A, Woron J, Dobrogowski J, Jakowicka-Wordliczek J, Wordliczek J. Topical clonidine for neuropathic pain. Cochrane Database Systematische Reviews. 2015; 8(9): CD010967. doi:10.1002/14651858.CD010967.pub2.
  5. Charney DS, Riordan CE, Kleber HD, et al. Clonidine and naltrexone. A safe, effective, and rapid treatment of abrupt withdrawal from methadone therapy. JAMA Psychiatry. 1982; 39(11): 1327–1332. doi:10.1001/archpsyc.1982.04290110077013.
  6. Cushman P Jr. Clonidine and alcohol withdrawal. Advances In Alcohol & Substance Abuse. 1987; 7(1): 17–28.
  7. Ming X, Gordon E, Kang N, Wagner GC. Use of clonidine in children with autism spectrum disorders. Brain and Development. 2008; 30(7): 454–460. doi:10.1016/j.braindev.2007.12.007.
  8. Lange JT, Lange CL, Cabaltica RB. Primary care treatment of post-traumatic stress disorder. American Family Physician. 2000; 62(5): 1035-40, 1046.
  9. Wagner ML, Walters AS, Coleman RG, Hening WA, Grasing K, Chokroverty S. Randomized, double-blind, placebo-controlled study of clonidine in restless legs syndrome. Sleep. 1996; 19(1): 52–58.

Published on: March 16th, 2020

Updated on: March 16th, 2020

About Author

Isaak Stotts, LP

Isaak Stotts is an in-house medical writer in AddictionResource. Isaak learned addiction psychology at Aspen University and got a Master's Degree in Arts in Psychology and Addiction Counseling. After graduation, he became a substance abuse counselor, providing individual, group, and family counseling for those who strive to achieve and maintain sobriety and recovery goals.


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