Clonidine Beta blockers

Clonidine (Catapres). Like the beta blockers, clonidine acts by reducing norepinephrine activity, though by a different mechanism. Studies show that clonidine can provide early relief from the symptoms of a panic attack, but patients unfortunately relapse with continued treatment. Therefore, clonidine is not used in the treatment of panic disorder. 

Intoxication Beta blockers Clonidine Benzodiazepines Antipsychotics... 

Intoxication Anxiety, agitation Supportive benzodiazepines, beta blockers, clonidine... 

Other Medications. A variety of other medications have been tried. These include hormone treatments and certain blood pressure medications (e.g., clonidine and the beta blockers). For the most part, these have met with minimal success and should not be considered a part of routine treatment. 

Drugs that may be affected by beta blockers include flecainide, gabapentin, haloperidol, hydralazine, phenothiazines, anticoagulants, benzodiazepines, clonidine, disopyramide, epinephrine, ergot alkaloids, lidocaine, nondepolarizing muscle relaxants, prazosin, sulfonylureas, and theophylline. 

Drugs that interact may include beta blockers, indomethacin, verapamil, and clonidine. 

Clonidine, a central acting antihypertension agent (q 2 adrenergic agonist) is classically cited as an antimigraine drug although it is less effective than beta-blockers. 

Geriatric Considerations - Summary Discontinuation of clonidine is likely to require a slow taper. If the patient is receiving a concomitant beta-blocker, the beta-blocker must be tapered and discontinued before discontinuing clonidine. Clonidine discontinuation in the presence of a beta-blocker can lead to severe hypertension and cardiovascular events due to unopposed alpha-receptor stimulation. CNS effects often preclude its use in older adults. A higher clonidine dose (0.4 mg/day) is generally needed to control peri- or postmenopausal vasomotor symptoms however, adverse effects often make it difficult to achieve effective doses. 

Beta-blockers interact with a large number of other medications. The combination of beta-blockers with calcium antagonists should be avoided, given the risk for hypotension and cardiac arrhythmias. Cimetidine, hydralazine, and alcohol all increase blood levels of beta-blockers, whereas rifampicin decreases their concentrations. Beta-blockers may increase blood levels of phenothiazines and other neuroleptics, clonidine, phen-ytoin, anesthetics, lidocaine, epinephrine, monoamine oxidase inhibitors and other antidepressants, benzodiazepines, and thyroxine. Beta-blockers decrease the effects of insulin and oral hypoglycemic agents. Smoking, oral contraceptives, carbamazepine, and nonsteroidal anti-inflammatory analgesics decrease the effects of beta-blockers (Coffey, 1990). 

Antihypertensives typically used in child psychiatry include a agonists (clonidine, guanfacine) and beta-blockers (propranolol, nadolol). 

CENTRALLY ACTING ANTI HYPERTENSIVES BETA-BLOCKERS Risk of withdrawal t BP (rebound t BP) with clonidine and possibly moxonidine Withdrawal of clonidine, and possibly moxonidine, is associated with t circulating catecholamines beta-blockers, especially non-cardioselective ones, will allow the catecholamines to exert an unopposed alpha action (vasoconstriction) Do not withdraw clonidine or moxonidine while a patient is taking beta-blockers. Withdraw beta-blockers several days before slowly withdrawing clonidine and moxonidine... 

Because amisulpride may dose-dependently prolong QTc interval, use with caution in patients who have bradycardia or who are taking drugs that can induce bradycardia (e.g., beta blockers, calcium channel blockers, clonidine, digitalis)... 

The hypertensive crisis that can follow the withdrawal of clonidine can be accentuated by beta-blockers. It has also been reported that when beta-blockers are used in conjunction with drugs that cause arterial vasoconstriction they can have an additional effect on peripheral perfusion, which can be hazardous. Thus, combining beta-blockers with ergot alkaloids, as has been recommended for migraine, can cause severe peripheral ischemia and even tissue necrosis (408). 

Clonidine (Catapres) is an alpha-2 adrenergic agonist, which thereby functions as a presynaptic irdiibitor of norepinephrine release. It is usually used to treat hypertension (like the beta blockers) but has been used to treat amciety disorders with some success. It is also used to treat opiate withdrawal. A typical starting dose is 0.1 mg two to three times daily (see figure 16-C). It is also available as a transdermal patch. 

Discuss the withdrawal of therapy with beta-blockers combined with clonidine. 

Those sympathoplegic drugs that act indirectly via the CNS include methyidopa and clonidine. Sympathoplegic drugs also may act directly as adrenergic neuron blockers, alpha blockers, or beta blockers. Examples of each class are provided. 

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