PDR for Herbal Medicines

HERBAL MONOGRAPHS SENNA /685

In addition, stimulation of active chloride secretion increases

water and electrolyte content of the intestine. These changes

in active electrolyte transport are dependent on calcium in

the serosal surface (Donowitz, 1984; Yamauchi, 1993). The

laxative action of Senna is partially via stimulation of

colonic fluid and electrolyte secretion, and this secretion is

mediated by stimulation of endogenous prostaglandin E2

formation (Beubler. 1988: Yamauchi, 1993).

CLINICAL TRIALS

Laxative Effects

A randomized, single-blind study evaluated the efficacy of

Senna compared to polyethylene glycol (PEG) for mechani-

cal preparation for elective colorectal resection. Five hun-

dred twenty-three patients included in the study were

undergoing resection, followed by anastomosis. All patients

received 5% providone iodine antiseptic enema before

surgery, and ceftriaxone sodium and metronidazole were

given at anesthesia induction. Senna was significantly better

than PEG with regard to colonic cleanliness and less fecal

matter in the colonic lumen. The risk for moderate or large

intraoperative fecal soiling was lower with senna and overall

clinical tolerance did not differ significantly between the

treatment groups. Senna was better tolerated in patients with

stenosis. There was no statistical difference between the

treatment groups with postoperative infective complications

or anastomotic leakage (Valverde. 1999).

A prospective randomized trial evaluated the efficacy of the

addition of senna to a polethylene glycol electrolyte lavage

solution (PEG-ELS). One hundred and twenty patients

received either a Senna extract with PEG-ELS or placebo

with PEG-ELS before a total colonoscopy. Superiority by

physician assessment was seen in the group with Senna. The

colon was free of solid debris in 66.7% of patients after

PEG-ELS and in 90% after Senna/PEG-ELS administration,

which was a significant difference. Patient tolerance was

similar in both groups, and significantly less lavage fluid was

needed in the Senna/PEG-ELS treatment group (Ziegenha-

gen, 1991).

A randomized, open, parallel group study was conducted to
determine the efficacy of senna compared to lactulose in
terminal cancer patients treated with opioids. Ninety-one
terminal cancer patients were treated with either senna
(starting with 0.4 mL daily) or lactulose (starting with 15 mL
daily) for a 27-day period. The main outcome measures were
defecation-free intervals of 72 hr, days with defecation,
general health status, and treatment cost. Both treatment
groups had similar scores for defecation-free intervals and in
days with defecation. The final scores for general health
status were similar in both groups (Agra, 1998).

INDICATIONS AND USAGE

• Constipation

Senna is used for constipation and for evacuation of the

bowel prior to diagnostic tests of the gastrointestinal and

colorectal area.

Indian Medicine: The herb is used for constipation, liver

disease, jaundice, splenomegaly, anemia, and typhoid fever.

Note: Stimulating laxatives must not be used over a period of

more than 1 to 2 weeks without medical advice.

CONTRAINDICATIONS

The herb is not to be administered in the presence of

intestinal obstruction, acute inflammatory intestinal diseases

or appendicitis.

PRECAUTIONS AND ADVERSE REACTIONS

General: Spasmodic gastrointestinal complaints can occur as

a side effect to the drug's purgative effect or from

overdosage. In rare cases, prolonged use may lead to cardiac

arrhythmias, nephropathies, edema and accelerated bone

deterioration. Senna abuse has also resulted in tetany,

aspartylglucosamine excretion, and. hypogammaglobulin-

emia (Levine, 1981; Malmquist, 1980; Prior, 1978).

Electrolyte Abnormalies: Long-term use leads to loss of

electrolytes, in particular potassium ions. As a result of

hypokalemia, hyperaldosteronism, albuminuria, hematuria,

inhibition of intestinal motility, and muscle weakness may

occur. Enhancement of cardioactive glycosides and antiar-

rythics may also occur with hypokalemia.

Finger Clubbing: Senna abuse has resulted in finger

clubbing, which was reversible upon discontinuation of the

drug (Levine, 1981; Malmquist, 1980; Prior, 1978; Silk,

1975).

Cathartic Colon: Anatomic alteration of the colon is seen

secondary to chronic use with Senna (more than three times

weekly for 1 year or longer). The result is a loss of haustral

folds, a finding that suggests neuronal injury or damage to

colonic longitudinal musculature (Joo, 1998).

Carcinogenesis: Carcinogenic activity in the colon following'"

long-term administration of anthracene drugs has not yet

been fully clarified. Study findings are controversial regard-

ing the correlation between the administration of anthracene

drugs and the frequency of carcinomas in the colon (al-

Dakan, 1995; Mereto, 1996).

Melanosis Coli: Prolonged use of Senna may lead to

melanosis coli. Precursors of the melanic substance in

melanosis coli may be derived from anthranoid laxatives

(Benavides, 1997).