Detailed Drug Information:

DRUG CLASS AND MECHANISM: Clonidine is an oral and topicalantihypertensive drug. It also has been used in several other conditionsincluding narcotic and nicotine withdrawal, certain types of vascularheadaches, and diarrhea associated with diabetes. Clonidine acts bystimulating adrenergic receptors on nerves in the brain. This stimulationactually reduces messages that originate in the central nervous system(brain) and are transmitted to the body by the sympathetic nervous system.As a result, clonidine slows the heart rate and reduces blood pressure.Clonidine was approved by the FDA in 1974.

GENERIC AVAILABLE: yes (tablets). No (patches).

PREPARATIONS: Tablets: 0.1mg, 0.2mg, 0.3mg. Transdermal patchesreleasing 0.1mg, 0.2mg. or 0.3mg over 24 hours.

STORAGE: Tablets and patches should be kept at roomtemperature, 15-30°C
(59-86°F).

PRESCRIBED FOR: Clonidine is most often prescribed for thetreatment of hypertension. It has also been used to manage the symptoms ofnarcotic withdrawal, nicotine withdrawal, diabetes-associated diarrhea,diabetic neuropathy, hot flashes associated with menopause, and as anadjunct to manage severe cancer-related pain.

DOSING: Clonidine tablets are usually given twice daily.Patches should be applied to an area of hairless skin on the upper arm ortorso, once every 7 days. When applying a new patch, a different area ofskin should be used.

DRUG INTERACTIONS: Clonidine can increase the sedating effectsof other medications that cause sedation. Such drugs include narcotic painrelievers, barbiturates, sedatives such as alprazolam (Xanax) andclonazepam (Klonopin), and ethanol. Tricyclic antidepressants [e.g.,amitriptyline (Elavil), imipramine (Tofranil), desipramine (Norpramin),clomipramine (Anafranil)] can block the blood pressure lowering effects ofclonidine. This may cause blood pressure to rise.

Since clonidine can reduce the heart rate, it should be used cautiouslyin persons who are receiving other medications that lower the heart ratesuch as beta-blockers [e.g., atenolol (Tenormin), metoprolol (Lopressor),propranolol (Inderal)], digoxin (Lanoxin), diltiazem (Cardizem), orverapamil (Calan; Covera HS). Abnormal heart rhythms can occur with thecombination of clonidine and verapamil. Cyclosporine (Sandimmune; Neoral)blood concentrations can increase when clonidine is begun. Thisinteraction could result in kidney damage. Nonsteroidal anti-inflammatorydrugs [e.g., ibuprofen (Motrin, Advil), naproxen (Naprosyn, Aleve),nabumetone (Relafen)] can reduce the antihypertensive effects ofclonidine. Cocaine, pseudoephedrine, phenylephrine, and phenylpropanolaminecan reverse the blood pressure lowering effects of clonidine.

PREGNANCY: There is very little information about the effectson the fetus of clonidine given to pregnant women. Clonidine has been usedduring pregnancy, but reported use during the first trimester is limited.Physicians may use it if its benefits are deemed to outweigh its potential(and unknown) risks.

NURSING MOTHERS: Clonidine is excreted into breast milk.Although clonidine has been found in the blood of nursing newborns whosemothers took clonidine, there are no cases reported of reduced bloodpressure in the infants. Nonetheless, since reports are very limited,caution is warranted in treating nursing mothers with clonidine.

SIDE EFFECTS: The most common side effects noted with clonidineare tiredness, lethargy, drowsiness, constipation, and dry mouth.Headache, dizziness, fatigue, and weakness also occur with clonidine. Mostpersons who experience one of these side effects will usually note thatthe effects subside with more prolonged therapy or if doses are reduced(approved by the physician). Skin reactions including redness, itching,and darkening of skin, have occurred with clonidine patches.

Sexual dysfunction including impotence, decreased sexual desire, andejaculatory dysfunction, have been reported with clonidine therapy. Suchreactions also have been reported with other medications used to treathypertension.

Severe rebound high blood pressure can occur following withdrawal fromclonidine. This reaction is more likely to occur if clonidine is stoppedsuddenly (without a gradual dose reduction). Symptoms can includeincreased salivation, nervousness, headache, heart palpitations,agitation, anxiety, sweating, nausea, muscle pain, and abdominal pain.Slowly reducing the dose of clonidine over several days will prevent thisproblem.