So-called alpha agonists are gaining popularity in the United States and Europe. Today, they are commonly used to treat a wide range of mental disorders, such as hyperkinetic disorder, Tourette’s syndrome, and post-traumatic stress disorder.
Some drugs belonging to the group of alpha agonists have even been approved by the American Food and Drug Administration (FDA). Clonidine is one of them.
Clonidine acts as a stimulant of presynaptic α2-adrenergic receptors of the brain inhibitory structures. It normalizes the imbalance in the systems of catecholamine release. Let’s consider the features of Clonidine in detail.
Clonidine has been used since the 1970s as an antihypertensive agent. In terms of chemical structure, it has similar elements with Naphthyzin and Phentolamine, which are adrenomimetic and a-adrenergic blocking agents, respectively. Like Naphthyzin, Clonidine stimulates peripheral a1-adrenergic receptors and has a short-term suppressive effect. After penetrating the blood-brain barrier, the drug stimulates the a2-adrenergic receptors of the vasomotor centers, reduces the flow of sympathetic impulses from the central nervous system, and reduces the release of norepinephrine from nerve endings, exerting equal sympatholytic and central noradrenergic effects. The hypotensive effect of the drug develops within 1-2 hours after oral intake and continues after a single dose for 6-8 hours.
Several studies have demonstrated that Clonidine is effective in the treatment of PTSD as it reduces symptoms of increased reactivity and agitation. Now, it is widely used to treat irritability, hyperactivity, and generalized anxiety disorder.
In children aged 3 to 8-9 years, Clonidine is used for the treatment of insomnia, impulsivity, and hyperactivity. Small doses of Clonidine in combination with stimulants are used to treat children with attention deficit hyperactivity disorder (ADHD) who have trouble falling asleep. Typically, the child takes the first dose of stimulant in the morning, the second dose during school lunch (11-12 hours), and Clonidine 0.1-0.2 mg at bedtime.
Sometimes, children may wake up in the middle of the night after taking Clonidine. In such cases, doctors recommend using a combination of Clonidine with melatonin or a small dose of an antihistamine.
Clonidine is available in 0.1 and 0.2 mg tablets. One of the disadvantages of Clonidine is a short-lasting effect (typically about four hours). Therefore, the drug is usually prescribed in 0.05-0.1 mg doses 3-4 times a day. To avoid the hypotensive effect in children, healthcare specialists try not to prescribe the drug in a dose higher than 0.4 mg per day.
It’s difficult to say how long Clonidine takes to reduce anxiety because of the individual differences. Each body reacts to the medicine in a unique way, so it’s almost impossible to predict the exact outcomes of treatment with Clonidine. It’s assumed that the substance starts working to the fullest after four weeks after determining the right dose. However, some symptoms might be relieved much sooner.
Note that the dose of Clonidine must be gradually adjusted by a doctor, not by yourself.