About Clonidine

3.5 rating based on 15 ratings
Rating: 3.4 Reviews: 15
About Clonidine

Clonidine is used in tablet form or as a solution for injection to reduce blood pressure in hypertension and normalize blood pressure over time.

What is the purpose of this ingredient?

  • Normalize elevated blood pressure
  • Lower elevated intraocular pressure in cataracts

This is how Clonidine works

Below you will learn more about the fields of application and the mode of action of clonidine.
Please also read the information on the drug class alpha-sympathomimetics,
to which the active ingredient clonidine belongs.

Areas of application of the active substance clonidine

Clonidine is used in tablet form or as a solution for injection to reduce blood pressure in hypertension and to normalize blood pressure over time.

Clonidine is used in the form of eye drops to lower the increased intraocular pressure in cataracts.

For the following application areas of Clonidine , in-depth information is available:

  • Hypertension
  • Green Star

Mode of action of clonidine

Clonidine belongs to the active ingredient group of the alpha-sympathomimetics effective in the brain and exerts its effect exclusively on the alpha-2-receptors. Alpha-2 receptors are special binding sites of the sympathetic fibers of the autonomic nervous system. Unlike alpha-1 receptors, they have no “turn on” function for sympathetic nervous system activity, but a “turn off” function. Clonidine acts on these receptors as well as the body’s messenger substances, only stronger and longer.

At the heart, clonidine lowers the number of heartbeats and thereby the volume of blood pumped. In addition, clonidine causes a widening of the arteries and veins. With dilated vessels, less blood volume and larger vessel diameter, the blood from the heart has to be pumped through the vessels with less pressure. As a result, the blood pressure drops. This effect is further supported by the fact that clonidine on the kidney attenuates the release of the blood pressure enhancing hormone renin.

On the eye, clonidine causes an improved outflow of aqueous humor. By contracting certain muscle fibers, the drainage channel (Schlemm’s canal) is opened, allowing faster drainage. In addition, clonidine can also slightly reduce the production of aqueous humor, which lowers the intraocular pressure.

Potential Clonidine side effects may include:

Clonidine used to treat the following diseases:


  1. Zachary M. Irwin says:
    3.5 rating

    Clonidine for High blood pressure

    After taking Catapressan 75 (clonidine) a very strong feeling of drowsiness, partly vertigo. mild nausea and sometimes vision problems. I will drop off the pills as soon as possible. Had Clonistada 250 ret. and stopped at the doctor’s instructions without compensation, with the result that very severe withdrawal symptoms occurred. These were: dizziness, uncontrolled high blood pressure, sweating and shaking. Once and never again!

    Side effects: Dizziness
  2. Jimmy R. McAlpin says:
    3.0 rating

    Hello, after taking Clonidine I have double vision when I open my eyes slowly. I see two pictures that slowly assemble into a picture. If I blink normally, it does not occur. My ophthalmologist says it goes away again there is no disturbance of the optic nerve or other parts of the eye. If it does not go away, I should go to a neurologist. Who has had similar experience and can say how long it takes. thanks and greetings Michael

  3. Virginia J. Bond says:
    4.0 rating

    Clonidine for High blood pressure

    Very strong itching with red spots, quite large on the extremities and in the groin. First lichen-like small spots, which subsided, however, as the pruritus (itching) increased. On cessation of discontinuation of ramipril occurrence of palpitations. In the short term also visual disturbances and edema at the lip.

  4. Manuel E. Cho says:
    5.0 rating

    Venlafaxin: I was pretty sick at the beginning and I felt restless. In the evening I had sleep problems, which I actually have, but I felt that things were getting worse. This went away after 4 weeks but the sleep problems remained. The dose had to be increased, after the 4 weeks, however, and the same started from the beginning. I also had absolute libido problems at the beginning. In the meantime, I got the maximum dose of 375 mg, which later was reduced to 225 mg, which I then took until recently, because it just did not bring much and I got another drug (Elontril). It helped a lot against my impulsivity in the beginning, but later it got more and more relaxed. Later in the case means after about 2 years. Other medicines such as Cymbalta or other sertonin and norepinephrine reuptake inhibitors, however, have done nothing. Risperidone: Risperidone left me relatively relaxed and a little tired, but otherwise I did not experience any side effects. I took 2 mg of it a day. My susceptibility to fall into a dissotiation was noticeably lower and I felt better with this drug. Clonidine: From clonidine, I realized that I was calmer and did not feel the urge to hurt myself. I had no side effects. Neurocil: From Neurocil I noticed a fast sedating effect, which was very strong for me. I just wanted to sleep afterwards and had problems talking. My thoughts were very funny and totally confused.

    Side effects: Libido loss
  5. Cora R. Duval says:
    4.0 rating

    Clonidine for High blood pressure

    On the advice of my family doctor, I wanted to discontinue clonidine because the side effects put too much pressure on me. Since I also take beta-blockers, I have first discontinued them, as stated in the package leaflet by Clonidine, otherwise there will be dangerous blood pressure fluctuations. Afterwards I have clonidine gradually The end of the song was that I was with my doctor with a blood pressure of 270/160 on the couch lag.Ich voluntarily started again with clonidine, which brought my blood pressure back into the normal range , but the side effects burden me even more. The side effects are: extreme fatigue, speech problems, blurred vision, loss of libido and what depresses me most of all depressive mood.

  6. Kathy M. Wilson says:
    2.5 rating

    Clonidine for High blood pressure

    First side effects of mild dizziness occurred after about one year. Meanwhile, I take the drug 3 years and the side effects are increasing. Vision problems, dizziness, extreme tiredness (especially at noon), libido loss, gait disorders

  7. Kerry J. Kline says:
    4.0 rating

    Clonidine for High blood pressure

    After a long, not to say very long, ordeal with the blood pressure adjustment, I was prescribed clonidine for a good one year. It was once again one of the much-sought emergency applications. After all, at that time, I had one or more medications in almost all areas of hypertension medication. Values around 250 to 140 or even higher were not uncommon. Due to the high pressure, I had no side effects, no headaches or anything else. Now I took 5 capsules daily at the beginning of clonodine – at last it had an effect. Although my blood pressure did not drop overnight, after a few weeks it stabilized at 150 to 100. Still it is too high, but for me after 6 years of super high values, my doctors and I are somehow satisfied. Maybe it stabilizes even further down. Side effects are limited. About an hour after taking I suffer from dry mouth. Thanks to chewing gum or candy, I can deal with it quite well.

    Side effects: Mouth dryness
  8. Philip D. Boettcher says:
    2.0 rating

    Clonidine was mixed in intrathecal morphine pump along with morphine and NACL. Clonidine was not tolerated, nausea, vomiting, dizziness as a side effect. Fixed with discontinuation of the drug side effect

    Side effects: Dizziness
  9. Melissa H. Murray says:
    4.0 rating

    Clonidine for High blood pressure

    Hi, I have to say that I am totally thrilled, I have had high blood pressure for 3 years and have been on metropolol 100, ramipril10mg, hct25, but over time it got worse, my doctor changed me to clonidine75 micrograms and I take in the evening a pill, the fatigue comes after about 2 hours but otherwise no problems I am thrilled and can only recommend the drug because Metropolol are only suitable for people with heart problems and not for hypertension.

    Side effects: Fatigue
  10. Derrick C. Wade says:
    4.0 rating

    Clonidine for High blood pressure

    Because of poorly adjustable medication for my high blood pressure 220/130/75 (before treatment with Carmen) I came to the observation for a week inpatients in Kardiocentrum / Frankfurt. Since nothing improved there you wanted to dismiss me after 7 days. As a last attempt I was given 40 mg Carmen with the result that my blood pressure within minutes from 220 to 100 was lowered. I was literally in the corner and if I had not been to the hospital that could have ended badly. Meanwhile, I’m well set with these values: 120/90 pulse 65 side effects with me from Carmen: thick legs / edema, blurred vision, weight gain, dehydration for dehydration I take 40 mg torasemide daily in further treatment and the doctors are now working on the side effects