Side Effects, Withdrawal & Signs of Overdose

Clonidine is a sedative and antihypertensive prescription medication commonly used to treat high blood pressure.

Clonidine falls under the Alpha-2-Agonist drug class and is also used in combination with other drugs to treat conditions like attention deficit hyperactivity disorder (ADHD), according to Medline Plus. Other uses for the drug include treatment for Tourette’s syndrome, anxiety issues, painful menstruation symptoms, and addiction-related withdrawal.

Clonidine does have abuse potential. It is often abused in conjunction with other drugs, such as methadone, heroin, and prescription painkillers, according to Everyday Health.

Short-Term Side Effects of Clonidine

The consumption of clonidine results in a decreased heart rate, one of the reasons it is so effective in treating high blood pressure. It relaxes an individual’s blood vessels, creating more room for easier blood flow. Clonidine can also interact with the section of the brain that controls impulsiveness, hence the correlation with ADHD.

• Drowsiness
• Dizzy spells
• Constipation
• Drying of the mouth

Clonidine may also have a sedative effect on a person in the short-term, which could lead to difficulty operating a motor vehicle or other machinery. Mixing clonidine with other depressants, such as alcohol, can be very dangerous due to a potentially enhanced effect of the substance.

Long-Term Side Effects of Clonidine

There is the potential for a multitude of adverse effects involving the use of clonidine. People taking the substance may experience fever, headaches, fatigue, and general weakness. More serious effects on the cardiovascular system are also possible. These effects can include heart palpitations, congestive heart failure, and atrioventricular blockage, among others. Such serious effects can be extremely dangerous and, in some cases, irreversible

The central nervous system can also be adversely affected by use of clonidine. Clonidine can bring about anxiety, hallucinations, depression, and sleep disorders. These effects can be severe and dangerous, and they should be treated by medical professionals in short order.

Gastrointestinal effects may also arise due to long-term use of clonidine. Nausea and vomiting can be side effects of the drug, as can abdominal pain. Some users experience constipation as well.

Ways to Get in Contact With Us

If you believe you or someone you love may be struggling with addiction, let us hear your story and help you determine a path to treatment.

There are a variety of confidential, free, and no obligation ways to get in contact with us to learn more about treatment.

• Call us at
• Verify Your Insurance Coverage for Treatment

Signs of Clonidine Addiction & Withdrawal

Addiction to clonidine is an effect of long-term use of the drug. Symptoms of clonidine addiction include:

• Uncontrollable use of the substance
• Becoming less accountable at home and/or work
• Increased tolerance

Individuals who have partaken in prolonged use of clonidine can become physically dependent on the substance. According to the Food and Drug Administration (FDA), withdrawal symptoms relating to clonidine include:

• Tremors
• Headaches
• Increased agitation
• Nervous behavior

Symptoms have become so severe in some cases that they have led to death, showing the seriousness of clonidine withdrawal. Those who witness these symptoms in an individual should contact medical professionals immediately.

Most of the mild long-term effects of clonidine use can be significantly diminished with therapy, but some effects can result in prolonged issues.

Take Our Substance Abuse Self-Assessment

Take our free, 5-minute substance abuse self-assessment below if you think you or someone you love might be struggling with substance abuse. The evaluation consists of 11 yes or no questions that are intended to be used as an informational tool to assess the severity and probability of a substance use disorder. The test is free, confidential, and no personal information is needed to receive the result.

Clonidine Overdose Symptoms

Overdose of the drug is possible, and it can have significant effects on the body. Hypertension, and later hypotension, may arise. Central nervous system depression can also come about, as can respiratory depression. Signs of overdose may include:

• Slowed heart rate
• Fainting
• Shivering
• Tiredness or Weakness
• Slurred Speech
• Drowsiness
• Coma

Finding Clonidine Treatment Near You

If you believe you or someone you love may be suffering from an addiction, rehab may be the right option for you. Explore our rehab centers across the United States.

About The Contributor

Editorial Staff

Author, American Addiction Centers

The editorial staff of American Addiction Centers is made up of credentialed clinical reviewers with hands-on experience in or expert knowledge of ad … Read More

Read Our Editorial Policy

opioid

Last Updated on Sep 13, 2022

What They Are and How to Manage Them

If you have high blood pressure, you may be interested in learning more about clonidine. It’s a generic prescription drug used to treat high blood pressure in adults.

Clonidine comes as a tablet that you take by mouth. It is also available as a patch, an injectable, or an extended-release tablet, but this article does not discuss these types.

If clonidine works for you, your doctor will likely recommend that you take it long term.

This article describes clonidine’s side effects, also known as adverse effects. For more information about clonidine, including details about its uses, see this in-depth article.

Some people may experience mild to serious side effects during their clonidine treatment. Examples of clonidine’s commonly reported side effects include:

• dry mouth*
• drowsiness or sedation*
• dizziness
• constipation

* To learn more about this side effect, see the “Side effects explained” section below.

Clonidine may cause mild side effects in some people. Examples of mild side effects that people taking clonidine have reported include:

• fatigue (low energy)
• headache
• anxiety or agitation
• blurry vision
• weakness
• fainting
• sleep problems such as vivid dreams or insomnia (trouble sleeping)
• dry mouth*
• dizziness
• drowsiness or sedation*
• constipation*
• nausea and vomiting
• sexual side effects*
• urinary side effects
• mild allergic reaction*†

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after using clonidine. But it’s not clear whether this side effect occurred in studies.

In most cases, these side effects should be temporary. And some may be easily managed. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And don’t stop taking clonidine unless your doctor recommends it.

Clonidine may cause mild side effects other than the ones listed above. See the drug’s prescribing information for details.

Serious side effects can occur during clonidine treatment, but this is uncommon.

Serious side effects that people taking clonidine have reported include:

• heart side effects, such as changes in heart rate or congestive heart failure
• hallucinations (seeing or hearing things that aren’t really there)
• mood changes such as depression
• liver problems
• low level of platelets (blood cells that help with blood clotting)
• severe allergic reaction†

If you develop serious side effects while taking clonidine, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after using clonidine. But it’s not clear whether this side effect occurred in studies.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with clonidine, visit MedWatch.

Get answers to some frequently asked questions about clonidine’s side effects.

Does my risk of side effects depend on the clonidine dose I’m prescribed (such as 0.1 mg, 0.2 mg, or 0.3 mg)?

Yes, it’s possible that your risk of side effects may vary based on what dose of clonidine you take. For example, people taking a higher dose, such as 0.3 milligrams (mg), may have a higher risk of side effects than someone taking a lower dose, such as 0. 1 mg.

Your doctor will monitor your blood pressure throughout your clonidine treatment. They may increase your dose over time to better manage your blood pressure. But this may raise your risk of side effects.

Your doctor will help determine the best dose of clonidine to manage your blood pressure. Most side effects are mild and may go away as you continue treatment. But if you experience bothersome side effects from clonidine, talk with your doctor about your dose.

Could I have withdrawal symptoms if I suddenly stop taking clonidine?

Yes, it’s possible to have withdrawal symptoms if you suddenly stop taking clonidine. (Withdrawal symptoms are side effects that can occur when you stop taking a drug that your body has become dependent on.)

Withdrawal symptoms that can occur when suddenly stopping clonidine treatment may include:

• nervousness or agitation
• headache
• tremor
• increased blood pressure
• stroke and death in rare cases

Due to these risks, you should not stop taking clonidine without first talking with your doctor. If you do need to stop treatment, your doctor will slowly decrease your dose over 2 to 4 days to lower your risk of having withdrawal symptoms. They may also recommend a different treatment option for your high blood pressure.

Is bradycardia (slow heart rate) a side effect of clonidine?

Yes, bradycardia is a possible side effect of clonidine. Though this was not one of the more common side effects in studies of clonidine, it can occur.

Symptoms of bradycardia may include:

• chest pain
• dizziness
• fatigue (low energy)
• fainting

Bradycardia can also be a symptom of an overdose of clonidine. Overdose symptoms can occur if you take too much clonidine. It’s important to always take the dose of clonidine that your doctor prescribes.

If you develop symptoms of bradycardia during your clonidine treatment, talk with your doctor.

Can taking clonidine cause weight gain or hair loss?

Yes, weight gain and hair loss could occur with clonidine use. But these side effects were not common in people taking clonidine in studies. And these people may also have been taking other blood pressure medications, so it’s unknown if clonidine caused the hair loss and weight gain.

If you experience hair loss during your clonidine treatment that bothers you, talk with your doctor. In some cases, they may be able to recommend over-the-counter medications such as minoxidil (Rogaine) to treat your hair loss.

If you experience weight gain during your treatment that concerns you, talk with your doctor. Though it’s possible for clonidine to cause weight gain, heart failure may also be a side effect of clonidine. And a symptom of heart failure is weight gain. Your doctor can try to determine what may be causing your weight gain and the best treatment options for you.

Do older adults have a higher risk of clonidine’s side effects than younger people?

Yes, older adults (ages 65 years or older) may have a higher risk of side effects from clonidine than younger people. This is because an older adult’s body may break down clonidine more slowly. This could cause the drug to build up in the body, which increases the risk of side effects.

Due to this risk, doctors may recommend that people ages 65 years or older take a lower dose of clonidine. Your doctor can determine what the best dose of clonidine is for you.

Learn more about some of the side effects clonidine may cause.

Dry mouth

Some people may experience dry mouth while taking clonidine. In fact, dry mouth was the most common side effect that people taking clonidine reported in studies.

What might help

If you develop a dry mouth during your treatment that bothers you, talk with your doctor. They may be able to recommend ways to manage this side effect, such as chewing gum or using mouthwash or lozenges.

Drowsiness or sedation

Drowsiness or sedation (extreme sleepiness) can occur from taking clonidine. These were common side effects that people taking clonidine reported in studies.

With sedation, you may move more slowly than usual or have slower reactions. Drowsiness can cause you to feel more sleepy than usual.

What might help

If you experience drowsiness or sedation from taking clonidine, talk with your doctor. In some cases, they may adjust your dose so that you take a higher dose before bed. This can help prevent sedation or drowsiness during the day.

Because clonidine can cause sedation or drowsiness, you should not drive or operate heavy machinery until you know how the drug will affect you.

Alcohol or other drugs that can cause sedation and drowsiness might worsen these side effects of clonidine. Your doctor may recommend that you avoid alcohol, other sedatives, or drugs that cause drowsiness while you’re taking clonidine.

Constipation

Clonidine may cause constipation in some people. This was a common side effect that people taking clonidine reported in studies.

What might help

If you develop constipation during your clonidine treatment, talk with your doctor. In some cases, they may recommend treatment options for your constipation. For example, taking an over-the-counter drug such as polyethylene glycol (MiraLAX) may relieve constipation.

Sexual side effects

Sexual side effects are possible while taking clonidine, but these side effects weren’t common in studies of the drug. Examples of sexual side effects that people taking clonidine reported include:

• decreased libido (sex drive)
• erectile dysfunction (ED)

What might help

If you have any sexual side effects during your treatment that bother you, talk with your doctor. They may recommend treatment for these side effects. For example, sildenafil (Viagra) may be used to treat ED. It’s important to note that many drugs used to treat ED, such as sildenafil, may lower your blood pressure. In some cases, this may be unsafe if you’re taking clonidine.

If you’re concerned about the sexual side effects of clonidine, talk with your doctor about your treatment options.

Allergic reaction

Like most drugs, clonidine can cause an allergic reaction in some people. But it’s not clear whether this side effect occurred in studies.

Symptoms can be mild to serious and can include:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)
• swelling under your skin, usually in your eyelids, lips, hands, or feet
• swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

• an antihistamine you take by mouth, such as Benadryl (diphenhydramine)
• a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to clonidine, they’ll decide if you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to clonidine, they may have you switch to a different treatment.

Keeping track of side effects

During your clonidine treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

• what dose of the drug you were taking when you had the side effect
• how soon you had the side effect after starting that dose
• what your symptoms were
• how it affected your daily activities
• what other medications you were taking
• any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how clonidine affects you. They can then use this information to adjust your treatment plan if needed.

Clonidine may not be right for you if you have certain medical conditions. These are known as drug-condition interactions. Other factors may also affect whether clonidine is a good treatment option for you.

Talk with your doctor about your health history before starting clonidine. Factors to consider include those described below.

Heart problems. If you have heart problems, tell your doctor before taking clonidine. This drug may cause heart problems. If you already have heart problems, taking clonidine may worsen your condition. Your doctor can determine if it’s safe for you to take clonidine with your condition.

Kidney problems. Before starting clonidine treatment, tell your doctor if you have kidney problems. This drug is removed from your body by your kidneys. If your kidneys are not working well, clonidine levels can build up in your body. This can raise your risk of side effects. If you have kidney problems, your doctor may prescribe a lower dose of clonidine. Or in some cases, they may prescribe a drug other than clonidine for your condition.

Allergic reaction. If you’ve had an allergic reaction to clonidine or any of its ingredients, your doctor will likely not prescribe clonidine. Ask them what other medications are better options for you.

Older adults. If you’re age 65 years or older, you may have a higher risk of side effects from clonidine. Your doctor may monitor you more closely during treatment to watch for side effects, and they may prescribe a lower dose of clonidine. Or in some cases, they may prescribe a drug other than clonidine for you.

Contact lenses. Clonidine may make your eyes dry, which can make contact lenses uncomfortable to wear. If you notice that your eyes are dry when taking clonidine, tell your doctor. They may recommend using eyedrops to relieve dry eye.

Alcohol and clonidine

Drinking alcohol while you’re taking clonidine is not recommended. This is because alcohol can raise the risk of side effects from clonidine, such as:

• sedation (extreme sleepiness)
• nausea and vomiting
• dizziness
• blurry vision
• headache

If you’re concerned about avoiding alcohol during your clonidine treatment, talk with your doctor.

Pregnancy and breastfeeding while taking clonidine

It’s unknown whether it’s safe to take clonidine during pregnancy. Human studies haven’t looked at this drug’s safety during pregnancy. But clonidine does cross the placenta, which means that a fetus would likely be exposed to the drug.

Taking clonidine while breastfeeding is not recommended. The drug passes into breast milk and could cause side effects in a child who is breastfed.

If you’re pregnant, breastfeeding, or planning to become pregnant or to breastfeed, talk with your doctor before taking clonidine.

Most side effects of clonidine are mild, but serious side effects are possible, too. If you have any questions about the side effects that clonidine can cause, talk with your doctor.

Examples of questions that may help you get started:

• Can clonidine cause long-term side effects?
• Do I have a higher risk of side effects due to my other medications?
• Is my risk of side effects higher when I first start treatment?
• Does my risk of side effects depend on the dosage I take?

To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

Description of CLONIDINE indications, dosages, contraindications of the active substance CLONIDINE

Rec.INN WHO registered drug interaction Included in preparations: list Pharmacological action Antihypertensive agent of central action. The mechanism of action is due to the stimulation of postsynaptic α 2 -adrenergic receptors of the vasomotor center of the medulla oblongata and reduces the flow of sympathetic impulses to the vessels and the heart at the presynaptic level. The hypotensive effect is due to a decrease in peripheral vascular resistance, a decrease in heart rate and cardiac output. With rapid intravenous administration, a short-term increase in blood pressure is possible due to stimulation of postsynaptic α 1 – vascular adrenoreceptors. Increases renal blood flow; increasing the tone of the brain vessels, reduces cerebral blood flow; has a pronounced sedative effect. The duration of the therapeutic effect is 6-12 hours. the central effects of the active substance, part of which has undergone resorption. Pharmacokinetics When taken orally, it is well absorbed from the gastrointestinal tract, Cmax max in blood plasma is reached after 2-4 hours. Protein binding is 20-40%. About 50% of the absorbed dose is metabolized in the liver. T 1/2 with normal kidney function – 12-16 hours, with impaired renal function – up to 41 hours. Excreted by the kidneys – 40-60% unchanged, through the intestines – 20%. Indications of the active substance clonidine For systemic use: arterial hypertension (including symptomatic hypertension of renal origin), hypertensive crisis. For topical use in ophthalmology: open-angle glaucoma (as monotherapy or in combination with other drugs that reduce intraocular pressure). Open list of ICD-10 codes h50.1 Primary open-angle glaucoma h50.3 Glaucoma, secondary, post-traumatic h50. 4 Glaucoma secondary to inflammatory disease of the eye h50.5 Glaucoma secondary to other diseases of the eye I10 Essential [primary] hypertension I15.0 Renovascular hypertension Dosing regimen Used orally, intramuscularly, intravenously, topically in ophthalmology. In case of systemic application, the dose, method and schedule of application, duration of treatment is determined individually, depending on the indications, the clinical situation and the dosage form used. When applied topically in ophthalmology, the dose and treatment regimen is determined individually, depending on the response to treatment and the development of side effects. Side effects From the side of the cardiovascular system: rarely – edema, bradycardia; with intravenous administration, orthostatic hypotension is possible. From the digestive system: decreased gastric secretion, dry mouth; rarely – constipation. From the side of the central nervous system and peripheral nervous system: feeling of fatigue, drowsiness, slowing down of the rate of mental and motor reactions; rarely – nervousness, anxiety, depression, dizziness, paresthesia. From the reproductive system: rarely – decreased libido, impotence. Allergic reactions: skin rash, itching. Other: nasal congestion. Local reactions: dryness of the conjunctiva, itching or burning in the eyes. Contraindications for use Hypersensitivity to clonidine; arterial hypotension, severe atherosclerosis of cerebral vessels, obliterating diseases of peripheral arteries, severe sinus bradycardia, SSS, AV block II and III degree, cardiogenic shock, depression (including history), simultaneous use of tricyclic antidepressants, simultaneous use of ethanol and other drugs that have a depressing effect on the central nervous system; pregnancy, lactation (breastfeeding), children and adolescents up to 18 years of age. Use during pregnancy and lactation Contraindicated for use during pregnancy, lactation (breastfeeding). Use in impaired renal function Use with caution in chronic renal failure. Use in children Contraindicated in children and adolescents under 18 years of age. Special instructions Systemic use of clonidine Use with caution after a recent myocardial infarction, with chronic renal failure. With a sudden cessation of therapy, withdrawal syndrome may develop: increased blood pressure, nervousness, headaches, tremors, nausea. When performing clonidine therapy in combination with beta-blockers, in order to avoid an undesirable increase in blood pressure in case of discontinuation of therapy, it is first necessary to gradually end the treatment with beta-blockers, and then also by slowly reducing the dose, stop taking clonidine. To prevent the occurrence of orthostatic hypotension with intravenous administration of clonidine, the patient should be in a supine position during administration and for 1. 5-2 hours after administration. Topical application in ophthalmology To reduce the systemic effect of clonidine after instillation, it is necessary to press the area of ​​the lacrimal sac with your finger for 1-2 minutes after instillation. Influence on the ability to drive vehicles and mechanisms During the period of treatment with clonidine, potentially hazardous activities that require increased attention and rapid psychomotor reactions should be avoided. Drug interactions In patients receiving beta-blockers, in the event of a sudden withdrawal of clonidine, a sharp increase in blood pressure is possible. It is believed that this is due to an increase in the content of catecholamines in the circulating blood and an increase in their vasoconstrictor action. Concomitant use of oral hormonal contraceptives may increase the sedative effect of clonidine. With the simultaneous use of tricyclic antidepressants (including imipramine, clomipramine, desipramine), the antihypertensive effect of clonidine decreases. Co-administration with clonidine may increase the duration of action of vecuronium. When used simultaneously with verapamil, there is a report of the development of heart block in a patient with arterial hypertension. It is believed that clonidine suppresses the increased production of catecholamines resulting from hypoglycemia, and therefore the symptoms of hypoglycemia (tachycardia, palpitation, increased sweating), which are caused by the influence of catecholamines. In addition, there are reports that clonidine increases blood glucose, apparently by reducing insulin secretion. This must be taken into account when using insulin at the same time. When switching from clonidine to captopril, the antihypertensive effect of the latter develops gradually. In the event of a sudden withdrawal of clonidine in patients receiving captopril, a sharp increase in blood pressure is possible. There are reports of reduced efficacy of levodopa and piribedil in patients with Parkinson’s disease. Co-administration with prazosin may alter the antihypertensive effect of clonidine. With the simultaneous use of propranolol, atenolol develops an additive hypotensive effect, sedation, dry mouth. When used simultaneously with cyclosporine, there is a report of an increase in the concentration of cyclosporine in the blood plasma.

Active substance CLONIDINE (CLONIDINUM) | Compendium – drug reference book

• Pharmacological properties
• Indications CLONIDINE
• Application of CLONIDINE
• Contraindications
• Side effects
• Special instructions
• Interactions
• Overdose
• Diagnosis
• Recommended analogues

No. 50 006

Clonidine-Darnitsa

tablets 0.15 mg blisters, No. 50

Darnitsa

Prices in pharmacies

Prices in pharmacies

Clonidine-ZN

solution for injection 0.01% 1 ml ampoule in a box, No. 10

Public health

Prices in pharmacies

clonidine is an antihypertensive agent that acts at the level of neurohumoral regulation of vascular tone. After passing through the BBB, clonidine selectively stimulates α ₂ -adrenergic receptors of the nuclei of the vasomotor center of the medulla oblongata, thereby inhibiting sympathetic impulses from the central nervous system, causing vasodilation and a decrease in blood pressure. A decrease in sympathetic activity is accompanied by a decrease in the level of catecholamines (especially noradrenaline) in blood plasma and urine, although clonidine does not have a direct effect on the synthesis of catecholamines, but inhibits the release of norepinephrine from nerve endings by a negative feedback mechanism as a result of stimulation of central α ₂ -adrenergic receptors. In addition to the central hypotensive effect, clonidine can also have a stimulating effect on peripheral postsynaptic α ₁ -adrenergic receptors, leading to vasoconstriction and increased blood pressure. This effect is sometimes seen after rapid IV administration of clonidine; slow administration of clonidine in the form of a bolus injection or intravenous infusion does not lead to an increase in blood pressure.

Clonidine is an imidazoline receptor agonist.

The use of clonidine leads to a decrease in heart rate, systolic and diastolic blood pressure, as well as TPVR. IOC and stroke volume decrease slightly. Long-term use of clonidine leads to a decrease in myocardial hypertrophy and an improvement in left ventricular function. Clonidine has a sedative and analgesic effect. Due to the central action, it is able to eliminate the somatovegetative manifestations of opiate and alcohol withdrawal. Clonidine lowers intraocular pressure by reducing secretion and improving the outflow of aqueous humor in the eye.

Rapidly and completely absorbed in the digestive tract; oral bioavailability approaches 100%. After taking clonidine inside C _{max in blood plasma is achieved after 1-2 hours. The hypotensive effect develops 30-60 minutes after ingestion and persists for 8-12 hours. 5 min, reaches a maximum severity after 15–20 min and persists for 4–8 hours. Clonidine has a high lipophilicity and is widely distributed in tissues, including the central nervous system. About 50% of clonidine circulating in the blood is metabolized in the liver to form inactive compounds; excreted in the urine (40-60%) and feces (10%). T ½ varies widely, averaging 12 hours (6-24 hours). Elimination of clonidine slows down in patients with severe renal insufficiency. Compared with men, women have a lower clearance of clonidine and a longer T ½ .}

hypertension, including for relief of hypertensive crisis; to eliminate withdrawal symptoms in drug addiction.

as an oral antihypertensive agent is usually prescribed at an initial dose of 0. 075 mg 2-3 times a day. If the hypotensive effect is insufficient, a single dose is increased every 1-2 days by 0.0375 mg to 0.15-0.3 mg per dose 3 times a day. With insufficient effectiveness of clonidine in high doses, treatment is supplemented with saluretics, reserpine, methyldopa and other antihypertensive drugs. With manifestations of atherosclerosis of the cerebral vessels, clonidine is prescribed in an initial dose of 0.0375 mg. The daily dose is usually 0.3–0.45 mg, sometimes 1.2–1.5 mg.

For parenteral administration of clonidine, the patient must be in the supine position. In / infusion is recommended at a rate of 0.2 mg / kg / min, but not more than 0.5 mg / kg / min. A single dose should not exceed 0.15 mg. If the recommended rate of administration is exceeded, an increase in systolic blood pressure may be observed (on average, 20 mm Hg above the initial level). If necessary, the daily dose of clonidine administered intravenously can reach 0.6 mg, divided into 4 injections.

For drug withdrawal, clonidine is administered orally in a hospital at 0.15-0.3 mg 3 times a day with an interval of 6-8 hours for 5-7 days. In the case of side effects, a single dose is gradually reduced over 2-3 days, and then, if necessary, clonidine is canceled.

cardiogenic shock, arterial hypotension, sick sinus syndrome, AV blockade, pronounced changes in cerebral vessels, depression.

xerostomia, constipation, hypersensitivity reactions. In the first days, a sedative effect, increased fatigue, drowsiness, dizziness are also noted. Exceeding the recommended doses can cause orthostatic hypotension, collapse, loss of consciousness, cardiac arrhythmias (especially in patients with pathology of the conduction system of the heart). In some cases, when using clonidine in high doses, gynecomastia, depression, pain in the parotid gland and the appearance of scanty nasal discharge are possible.

during treatment with clonidine, blood pressure should be monitored regularly. During treatment, the use of alcohol is prohibited. When performing various types of operator activities, it should be borne in mind that clonidine reduces the speed of mental and physical reactions. Sudden cancellation of clonidine can lead to the development of a withdrawal syndrome (hypertensive crisis, irritability, tremor, headache, nausea), therefore, before canceling it for 7-10 days, it is necessary to gradually reduce the dose. With the development of the withdrawal syndrome, they immediately return to taking clonidine and subsequently cancel it gradually, replacing it with other antihypertensive drugs. To prevent withdrawal syndrome, clonidine should not be prescribed to patients who do not have the conditions for its regular use. In hypertension in patients with pheochromocytoma, the use of clonidine has no effect.

clonidine should not be given concomitantly with high doses of antidepressants and antipsychotics. The hypotensive effect of clonidine may be enhanced with the simultaneous use of other antihypertensive drugs (diuretics, vasodilators, β-adrenergic blockers).