severe adverse events associated with moxonidine in this RCT were gastrointestinal symptoms, dizziness, headache and tiredness; all of which occurred in between 10 to 15% of the patients receiving moxonidine. Indications for centrally acting alpha-agonists. Since alpha-agonists do not interact with other commonly used antihypertensive agents, they are valuable as adjunctive therapy for high BP in CKD patients already taking other antihypertensive medications. Because of the side-effect profile, however, caution is advised when using alpha- agonists in the elderly, in patients with advanced CKD and in those taking sedating drugs. In one large study of non-CKD patients with advanced heart failure, high-dose moxonidine use was associated with How this relates to patients with CKD is unclear. Avoidance is probably wise if overt heart failure is present. Since clonidine can slow pulse rate, this drug should be avoided if bradycardia or heart block is present. Drug combinations. Combination of alpha-agonists with thiazides is probably advantageous to reduce vasodilatation- induced fluid retention. Combination with other antihyperten- sive drugs is usually trouble-free, but caution is advised if the agents have similar side effects. Interactions are not common between alpha-agonists and CNIs or mTOR inhibitors. Alpha-blockers Alpha-adrenergic blockers selectively act to reduce BP by causing peripheral vasodilatation. Prazosin, doxazosin, and terazosin are the alpha-blockers most commonly used in treatment of hypertension. Alpha-blockers are an adjunctive treatment for elevated BP in CKD patients in whom ACE-Is, ARBs, diuretics, calcium-channel blockers, and beta-blockers have failed or are not tolerated. Alpha-blockers may also be advantageous if symptoms of prostatic hypertrophy are present. Dose considerations in CKD patients. Alpha-blockers do not require dose modification in cases of kidney failure, since they are excreted via the liver.4 Indications for alpha-blockers. 