35 下列瀉劑中，何者於口服後最快產生藥效？
(A) Bisacodyl
(B) Sodium phosphate
(C) Senna
(D) Psyllium

Stimulant laxatives

Stimulant laxatives include the following:

Bisacodyl or bisacodyl rectal - Stimulates peristalsis potentially by stimulating the colonic intramural neuronal plexus; alters water and electrolyte secretion, resulting in net intestinal fluid accumulation and laxation;

provokes defecation within 24 hours and may cause abdominal cramping

Senna - Sennosides induce defecation by acting directly on the intestinal mucosa or nerve plexus, which stimulates peristaltic activity, increasing intestinal motility; senna usually produces its action 8-12 hours after administration

Saline laxatives  

Saline laxatives are used for acute treatment of constipation in the absence of bowel obstruction

increase peristaltic activity of the colon by promoting osmotic retention of fluid

Sodium acid phosphate

Sodium phosphate rectal

高滲透壓型瀉劑，常用在手術前。像是fleet

onset:0.5-3小時(oral)

Psyllium車前子

Bulk-producing laxatives

吸水型，約12-72小時有作用

(B) Sodium phosphate 直腸給藥onset為2-15分鐘