Oxybutlin hydrochloride is the most frequently used agent and is the only anticholinergic medication approved by the Food and Drug Administration for relief of bladder instability. A dose of O.3mg/kg/day in a b.i.d. or t.i.d. dose schedule is appropriate. Dicyclomine hydrochloride and flavoxate hydrochloride have musculotrophic and anticholinergic activity which may benefit patients with urge incontinence. Terodiline hydrochloride combines both anticholinergic and calcium channel blocking properties. While promising, its current investigation in the U.S. has been suspended. The side effects of any anticholinergic agent (flushing, elevated body temperature, dry mucous membranes, palpitations, constipation) must be discussed with the family and child to prevent undue anxiety if they occur. Nocturnal enuretics. Children suffering from primary nocturnal enuresis can be treated with behavior modification using an enuretic device, pharmacological management, or a combination of both. An enuretic alarm, when used appropriately, has a success rate of 70% to 80% When relapses occur, further response can be obtained by reinstitution the alarm. However, the enuretic alarm does not provide immediate success and requires a well-motivated child and supportive family. If the enuretic alarm fails, it is often because of the lack of patient education regarding appropriate usage. It is essential to provide explicit instructions and follow-up when using an enuretic alarm. Imipramine hydrochloride is an effective treatment for enuresis in approximately 60% to 70% of cases. However, tolerance to the drug and relapses of enuresis occur in approximately 40% of children. Resuming the same dosage is often unsuccessful in controlling enuresis. Pharmacologically' imipramine acts in several ways. It has central and peripheral anticholinergic effects. lt blocks the uptake of norepinephrine and also acts as a sedative. lrnipramine has a strong inhibitory effect on the bladder smooth muscle that is unrelated to anticholinergic or adrenergic properties. The exact mechanism of action in regard to imipramine on nocturnal enuresis is unknown but the drug is believed to be effective, apart from the depressant effect. from its antidepressant effect. Imipramine toxicity is rare but can occur with early symptoms of flushing, dry mucous membranes, blurred vision, tachycardia, hyperactivity, and seizures. Its use can cause death. Therefore, when prescribing imipramine, the toxic effects must be discussed with the family. This agent should be used with caution when younger siblings are present, to prevent accidental ingestion. DDAVP (desmopressin acetate), a synthetic analogue to ADH, has been available for use in treatment of nocturnal enuresis since 1990. This pharmacological agent has a success rate of 40% to 70%, which is equivalent to that of enuretic alarms. Its advantages are ease of administration and rapid onset of action. Adverse reactions are limited and may include transient headache, nausea, nasal congestion, rhinitis, flushing, and mild abdominal cramps. DDAVP is particularly well suited for the child who has plans for a camping outing or sleep-over. Its disadvantages include cost and persisting enuresis once the medication is stopped. Combination therapies (e.g., using the enuretic alarm and DDAVP) may be helpful in treating the child refractory to other programs.