Catapres — clonidine HCL

Clonidine is a centrally acting alpha-agonist hypotensive agent. It is most commonly prepared as a hydrochloride salt for use in tablets and capsules, although it is also supplied in oral liquids, injectable solutions, and transdermal patches. Clonidine stimulates alphaadrenoceptors in the brain, which reduces sympathetic outflow from the central nervous system. This decreases the heart rate, and relaxes the blood vessels so that blood is allowed to flow more easily. Clonidine is widely prescribed for the treatment of hypertension (abnormally high blood pressure), which can have serious health implications if left untreated. Bodybuilders typically use this drug for the same purpose, namely to counter blood pressure elevations caused by anabolic/androgenic steroid use. Clonidine is also commonly prescribed for off-label purposes including the treatment of alcohol, opiate, and nicotine addiction, menopause symptoms, diabetic diarrhea and neuropathy (nerve damage), and ulcerative colitis. Clinical studies show that clonidine can also produce a significant increase in the serum growth hormone level. This occurs via stimulation of hypothalamic GHRH (Growth Hormone Releasing Hormone) release, which in turn supports the secretion of growth hormone from the pituitary. Given the known anabolic properties of growth hormone, clonidine is sometimes specifically chosen by bodybuilders (when a blood pressure medication is needed) because of its perceived added metabolic benefits. Realistically, however, this drug is rarely reported to produce performance or body composition improvements. This may be due to its effects on GH being short lived. Studies suggest that in many patients, clonidine will not result in sustained increases in GH with continued daily use. The prescribing literature even warns that its GH elevating properties are acute, and do not result in chronic elevations with long-term use. Clonidine may be of value for blood pressure management or other off-label purposes, but at the present time it is not widely accepted as a GH stimulating drug for bodybuilders. Oral clonidine is considered a fast acting medication. Its blood pressure lowering effects are typically noticed within 30 to 60 minutes after ingestion. Peak blood levels are achieved within 3-5 hours after administration, and the drug is metabolized with a half-life of approximately 12-16 hours. Given the short acting nature of the drug, clonidine is usually administered at least twice per day in order to maintain therapeutically effective blood levels. Food does not appear to influence the pharmacokinetics of clonidine. The absorption of clonidine from transdermal patches may be significantly delayed in comparison to oral tablets, and may take 2-3 days before peak blood levels are achieved. Tolerance to the blood pressure lowering effects of clonidine may develop over time. It may be necessary to periodically reevaluate the dosage during prolonged therapy. Clonidine may be used alone, but is also commonly combined with a second antihypertensive agent when a stronger blood-pressure lowering effect is required.

Brand name Catapres, Clonidine HCL

Clonidine HCL History

Clonidine first appeared in clinical studies during the late 1960s, and was approved by the U.S. Food and Drug Administration for prescription sale in 1974. Over the years, its favorable safety profile and level of efficacy have allowed it to become a somewhat common first-line option for the treatment of hypertension. The most widely known trade name for clonidine is Catapres, sold in many different countries by the international pharmaceutical manufacturer Boehringer-Ingelheim. In the United States, clonidine products are also available through many generic drug manufacturers including Actavis, Bertek, Global, Mutual, Mylan, Par, Qualitest, UDL Laboratories, Unichem, and Xanodyne.

How is Clonidine HCL Supplied

Clonidine hydrochloride is most commonly supplied in oral tablets of 0.1, 0.2, and 0.3 mg each.

Structural Characteristics of Clonidine HCL

Clonidine is an alpha-agonist hypotensive agent derived Clonidine is an alpha-agonist hypotensive agent derived from imidazoline. It has the chemical designation 2,6- dichloro-N-2-imidazolidinyldenebenzenamine.

Clonidine HCL Warnings

Abrupt discontinuation of clonidine may result in side effects including rebound hypertension, nervousness, agitation, headache, and/or tremor. In rare instances clonidine withdrawal has been associated with serious cerebrovascular accident and even death. Patients should not discontinue clonidine treatment without consulting their physician. When discontinuing clonidine, it is usually advised to slowly reduce the dosage over a minimum period of 2-4 days to reduce withdrawal symptoms.

Clonidine HCL Side Effects

Common side effects associated with clonidine treatment include dry mouth (40% of patients during clinical studies), drowsiness (33%), dizziness (16%), constipation (10%), and sedation (10%). Less frequent adverse reactions include physical fatigue, fever, increased sensitivity to alcohol, abnormal heart beat, congestive heart failure, delirium, insomnia, nightmares, paraesthesia (tingling of the skin), hair loss, rash, abdominal pain, anorexia, hepatitis, vomiting, decreased libido, erectile dysfunction, frequent waking to urinate during the night (nocturia), leg cramps, muscle pain, blurred vision, and dryness or burning of the eyes. Some side effects appear to be dose-dependant. Taking more than the prescribed amount (overdosage) may result in serious adverse reactions including hypotension (low blood pressure), respiratory depression, impaired motor reflexes, weakness, drowsiness, hypothermia, heart irregularities, coma, or death.

Clonidine HCL Administration

When used medically to treat hypertension, the dosage must be tailored to the individual needs of the patient. The usual initial starting dosage in adults is .1 mg given twice daily, morning and evening (.2 mg per day). This dosage may be increased once per week by .1 mg/day until the proper maintenance dosage is achieved. An effective therapeutic maintenance dosage usually rests between .2 mg and .6 mg per day, although a small percentage of patients require significantly higher amounts (2.4 mg/day is considered the maximum therapeutic dosage).

When used by bodybuilders to offset elevated blood pressure due to anabolic/androgenic steroid use, therapeutic use guidelines are usually followed. Some users will initiate clonidine at sub-therapeutic dosages (.1 mg per day) if they are unsure of their responsiveness to the drug, or their relative need for a hypotensive agent. Individuals should be reminded that it is important to monitor blood pressure closely whenever taking any medications that can have hypertensive or hypotensive effects.

Clonidine HCL Availability Trends

Clonidine is widely sold throughout the developed world. Low demand, low cost, and high availability make this drug a low-profit target for counterfeiting. Counterfeits are unlikely to be a significant problem.

Bodybuilders reference

This is a drug used to treat high blood pressure (antihypertensive). Bodybuilders and other athletes using AAS often experience this problem due to increased water retention and elevated blood counts. The reason this drug is included here is simple: It raises serum levels of GROWTH HORMONE (GH) by stimulating production from the pituitary gland. Some athletes reported taking 0.3 mg -0.15 MG on an empty stomach both when going to bed and upon waking with a total of 0.18 mg per day, maximum. Personally I disliked the drug due to its many negative side effects such as potency problems, laziness, vertigo, and a few others. The use of antihypertensive drugs without a doctor's guidance is dangerous. Those prone to low blood pressure could die, those with high blood pressure could miss the safe dosage and do the same.

Newbies Research Guide reference

Catapres is an antihypertensive drug. In school medicine it is used to reduce high blood pressure. High blood pressure caused by steroids can be lowered by taking Catapres. Athletes became interested in this drug when medical research reported that Catapres stimulates the endogenous production of the growth hor- mones. It should also be taken before going to sleep at night and in the morning immediately after getting up. Some athletes take a 0.3-mg tablet at night and a 0.15-mg tablet on an empty stomach immediately after waking up in the morning. The nightly dose increases the concentration of growth hormones for several hours, which then again can be increased by taking the morning dose. The achieved serum concentration is significantly above the normal value so that Catapres does have a considerable anabolic effect. Athletes, however rarely use it since it has several undesirable side effects such as lethargy, fatigue, dry mouth, potency disturbances, and vertigo those who have a low blood pressure and a low heart rate should be extremely careful when using it. One hundred tablets are available for approx. $60. on the black market.


Wlliam Llewellyn (2011) - Anabolics
L. Rea (2002) - Chemical Muscle Enhancement Bodybuilders Desk Reference
Newbies Research Guide

Your experience with Catapres — clonidine HCL

There are no comments yet.