Methyldopa MAOIs

Pseudoephedrine (Sudafed, Novafed, Afrinol, Others) [OTC] [Decongestant/Sympothomimetic] Uses Deconge tant Action Stimulates a-adren gic rec tors w/ vasoconstriction Dose Adults. 30-60 mg PO q6—8h Peds. 4 mg/kg/24 h PO qid -1- in renal insuff Caution [C, +] Contra Poorly controlled HTN or CAD, w/MAOIs Disp Tabs, caps, Liq SE HTN, insomnia, tach, arrhythmias, nervousness, tremor Interactions T Risk of HTN crisis W/ MAOIs T effects W/BBs, sympathomimetics X effects W/TCAs -1- effect OF methyldopa, reserpine EMS Found in many OTC cough/cold pr >arations use sympathomimetics w/ caution, may T adverse effects OD May cause N/V, HTN, arrhythmias, and Szs symptomatic and supportive... 

Methyldopa [Aldomet) [Antihypertensive/Centrally Acting Antiadrenergic] Uses HTN Action Centrally acting antihypertensive Dose Adults. 250-500 mg PO bid-dd (max 2-3 g/d) or 250 mg-1 g IV q6-8h Peds. 10 mg/kg/24 h PO in 2-3 + doses (max 40 mg/kg/24 h - q6-l2h) or 5-10 mg/kg/dose IV q6-8h to total dose of 20—40 mg/kg/24 h i in renal insuff/elderly Caution [B (PO), C (IV), +] Contra Liver Dz MAOIs Disp Tabs, inj SE Discolors urine inidal transient sedadon/drowsiness frequent, edema, hemolydc anemia, hepadc disorders Interactions T Effects W/ anesthetics, diuredcs, levodopa, Li, methotrimeprazine, thioxanthenes, vasodilators, verapamil T effects OF haloperidol, Li, tolbutamide 1 effects W7amphetamines, Fe, phenothiazine, TCAs 1 effects OF ephedrine EMS Use diuredcs, verapamil, and sympathomimedcs w/ caudon may T risk hypotension, arrhythmias and pressors effects OD May cause profound hypotension, drowsiness, and impaired myocardial conduction activated charcoal may be effective... 

ADRENERGIC NEURONE BLOCKERS-GUANETHIDINE CENTRALLY ACTING ANTIHYPERTENSIVES-METHYLDOPA MAOIs Risk of adrenergic syndrome (see above). Reports of an enhanced hypotensive effect and hallucinations with methyldopa, which may cause depression Due to inhibition of MAOI, which breaks down sympathomimetics Avoid concurrent use. Onset may be 6-24 hours after ingestion... 

Monoamine oxidase inhibitors and many pharmacological agents are synergistic, sometimes resulting in a hypertensive crisis. The agents with which the MAOIs may be synergistic include amphetamine, dextroamphetamine, methyl amphetamine, ephedrine, procaine preparations (which usually contain norepinephrine), epinephrine, methyldopa, and phenylpropanolamine (over-the-counter cold preparations). 

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