Clonidine Central nervous system depressants

As little as 0.1 mg of clonidine has produced toxicity in children determination of adult toxicity is based on observation as there is no milligram per kilogram toxic dose established. Clonidine levels are not clinically useful. Toxicity can result from ingestion of used clonidine transdermal patches as residual clonidine remains after full therapeutic use. Symptoms generally begin within 30-90 min and include hypotension, central nervous system depression, bradycardia, and... 

Clonidine should be used with caution in patients with cerebral, or coronary insufficiency, Raynaud s disease or throraboangitis obliterans, or with a history of depression. The hypotensive effect may be antagonised by tricyclic antidepressants, and enhanced by thiazide diuretics. Clonidine cause drowsiness and patients should not drive or operate machinery where loss of attention could be dangerous. The effect of other central nervous system depressants may be enhanced, withdrawal of clonidine therapy should be gradual as sudden discontinuation may cause rebound hypertension which may be severe. Agitation,... 

Drug overdose Toxicity from a clonidine suspension due to either a compounding or a liquid dosing error has been reported in a 3-year-old child who was given the drug for night terrors he developed a dry mouth, constricted pupils, intermittent gasping, and central nervous system depression [89" ]. 

Nicotine dependence may respond to replacement therapy with either nicotine gum or transdermal patches, and detoxification from nicotine dependence has been described using clonidine. Bupropion, an antidepressant, also shows efficacy for smoking cessation. The nicotinic receptor blocker mecamylamine, which has good central nervous system access, has been used with limited efficacy. Overall, success rates for smoking abstinence at 1 year are about 20%, with even less success for depressed smokers. 

Treatment with centrally acting agents is characterized by a relatively high incidence (up to 60% in some studies) of nervous system depressant effects (dizziness, drowsiness, tiredness, dry mouth, headache, depression), particularly during the initial period of treatment or after dosage increments. Sedation, lethargy, and tiredness are common with clonidine, particularly at the start of treatment (13). 

C. Anecdotal reports suggest that high-dose naloxone may partially reverse the central nervous system and respiratory depression associated with clonidine (see p 169), ethanol (see p 190), benzodiazepine (see p 130), or valproic acid (see p 362) overdoses, although these effects are inconsistent. 

An advantage of clonidine is the absence of orthostatic hypotension, but like a-methyldopa and reserpine it may cause drowsiness, and marked sedation occurs in up to 50% of patients treated in some series. Sedation can be so severe as to proceed to semi-consciousness. Nightmares and delusions are another expression of the drug s influence upon the central nervous system. Apart from sedation, the complaint of dry mouth and nose is the most common side effect recorded with clonidine administration. Dizziness, headache and fatigue are frequently mentioned, as well as anorexia, nausea, constipation and even pseudo-obstruction (94 ), anxiety, depression, drug fever and rashes. Side effects occur in 50—70% of the patients treated and are in some 20% the reason for discontinuation of therapy (3 , 13, 83 ). 

Common adverse events clonidine has a centrally mediated sedative effect. Other CNS depressants, such as benzodiazepines and opioids, may enhance the sedative effects of clonidine. Neuraxial clonidine can also affect the sympathetic nervous system, resulting in hypotension and bradycardia. When clonidine is used as a neuraxial adjunct analgesic, its hemodynamic effects may be enhanced by other neuraxial medications, particularly as local anesthetics. AU effects are dose- dependent. 

Nervous system Clonidine has been successfully used for impulsive and oppositional behavior in attention-deficit hyperactivity disorder as well as for its centrally mediated sedative action when taken late in the day. A child who took clonidine for this indication had night terrors shortly after initial therapy, insomnia during attempts at drug withdrawal, and depression when the drug was finally tapered and stopped... 

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