Clonidine is a prescription centrally acting alpha adrenergic agonist used primarily for the treatment of hypertension (high blood pressure). The 100mcg strength is equivalent to 0.1mg of clonidine hydrochloride, a standard oral tablet strength available in Canada. Health Canada currently lists 0.1mg clonidine hydrochloride tablets as prescription medications. Clonidine works primarily by stimulating alpha 2 adrenergic receptors within the brainstem. Activation of these receptors reduces sympathetic nerve signals travelling from the central nervous system to the heart and blood vessels. This results in decreased peripheral vascular resistance, reduced heart rate and lower blood pressure.
The sympathetic nervous system normally increases heart rate, vascular tone and blood pressure through the release of neurotransmitters such as norepinephrine. By decreasing this sympathetic output, clonidine produces a central sympatholytic effect, distinguishing it from medications that lower blood pressure primarily through direct vascular relaxation or beta receptor blockade.
Clonidine is established as an oral antihypertensive medication and may be prescribed alone or alongside other blood pressure lowering therapies. Its effects on sympathetic signaling have also led to use in other clinical settings, although these applications can depend on the formulation and jurisdiction. Clonidine is sometimes prescribed off label for ADHD, particularly when symptoms such as hyperactivity, impulsivity or sleep difficulties are present. Extended release clonidine formulations have specific ADHD indications in some jurisdictions, while immediate release tablets such as the 100mcg formulation may be used off label at the discretion of a healthcare professional.
Clonidine has also been used clinically to help manage certain symptoms associated with drug or opioid withdrawal, where reducing excessive sympathetic activity may help with symptoms such as sweating, agitation, elevated heart rate and blood pressure changes. These uses should be medically supervised.
This product provides:
- Active Ingredient: Clonidine Hydrochloride
- Strength: 100mcg (0.1mg) per tablet
- Quantity: 100 Tablets
- Drug Class: Centrally Acting Alpha 2 Adrenergic Agonist
- Dosage Form: Oral Tablet
- Primary Use: Management of Hypertension
The 100mcg strength is equivalent to 0.1mg, which is one of the established immediate release clonidine tablet strengths. Current prescribing information also lists 0.2mg and 0.3mg tablet strengths.
Common adverse effects can include drowsiness, dry mouth, dizziness, fatigue, constipation and sedation. Because clonidine reduces sympathetic activity and blood pressure, some patients may also experience slow heart rate or orthostatic hypotension. One of the most important safety considerations with clonidine is abrupt discontinuation. Suddenly stopping clonidine after regular use can cause rebound sympathetic activity and a rapid increase in blood pressure, sometimes accompanied by nervousness, agitation, headache or tremor. Treatment should therefore generally be reduced gradually under medical supervision rather than stopped suddenly.
Additional caution may be required when clonidine is combined with other medications that lower blood pressure, heart rate or central nervous system activity, as these combinations can increase dizziness, sedation, bradycardia or hypotension.
Clonidine is a prescription medication and should be used according to the directions and monitoring recommendations of a qualified healthcare professional.
