Constipation

Atina Hussaana

Dept. Pharmacology & Therapy

Medical Faculty of UNISSULA

Definitions of constipation include :

fewer than 3 stools / week for women & 5 for men despite a high-residue diet or a period of greater than 3

days without a bowel movement;

straining at stool greater than 25% of the time and/or 2 or fewer stools per week;

straining at defecation and less than one stool daily with minimal effort.

DEFINITION

Mengejan selama BAB lebih dari 25% waktu

Kotoran keras lebih dari 25%

Tidak lempias paska BAB lebih dari 25%

Frekuensi BAB 2 kali atau kurang dari 2 kali dalam

seminggu

PATHOPHYSIOLOGY

Constipation is not a disease but a symptom

of an underlying disease / problem :

Disorders of the GI tract (irritable bowel syndrome / diverticulitis), metabolic

disorders (diabetes) or endocrine disorders

(hypothyroidism) may cause constipation.

Constipation commonly results from a diet low in fiber / from use of constipating

drugs such as opiates.

Constipation may sometimes be psychogenic in origin.

Diseases or conditions that may cause constipation are:

GI disorders. Irritable bowel syndrome, diverticulitis, upper & lower GI tract

diseases, hemorrhoids, anal fissures, ulcerative proctitis, tumors,

hernia, volvulus of the bowel, syphilis, TBC, lymphogranuloma

venereum, Hirschsprungs disease.

Metabolic & endocrine disorders. Diabetes mellitus with neuropathy, hypothyroidism, panhypopitui-

tarism, pheochromocytoma, hypercalcemia, enteric glucagons excess.

Pregnancy. Neurogenic constipation. Head trauma, CNS tumors, spinal cord injury, cerebrospinal

accidents, Parkinsons disease.

Psychiatric disorders. Inappropriate bowel habits. Causes of drug-induced constipation are listed in Table 22-1.All opiate derivatives are associated with constipation, but the degree of intestinal inhibitory effects seems to differ between agents.

Orally opiates greater inhibitory effect than parenterally Oral codeine is well known as a potent antimotility agent.

DESIRED OUTCOME

A major goal :

prevention of constipation by alteration

of lifestyle (particularly diet) to prevent

further episodes of constipation.

For acute constipation, the goal :

to relieve symptoms & restore normal

bowel function.

TREATMENT

GENERAL APPROACH

The patient should be :

1. Asked about the frequency of bowel movements &

the chronicity of constipation.

2. Be carefully questioned about usual diet & laxative

regimens.

Does the patient have a diet consistently deficientin high-fiber items and containing mainly highly

refined foods?

What laxatives or cathartics has the patient used toattempt relief of constipation?

3. Be questioned about other concurrent medications,

with interest toward agents that might cause

constipation.

Beneficial in managing constipation :

dietary modification to increase the amount of fiberconsumed daily

exercise adjustment of bowel habits so that a regular &

adequate time is made to respond to the urge to

defecate

increasing fluid intake.

If an underlying disease is recognized as the cause of

constipation, attempts should be made to correct it.

GI malignancies may be removed through a surgical resection.

Endocrine & metabolic derangements are correctedby the appropriate methods.

DIETARY MODIFICATION &

BULK-FORMING AGENTS

The most important aspect of the therapy for constipation

dietary modification to increase the amount of fiber consumed : include at least 10 g of crude fiber in daily

diets (fruits, vegetables, and cereals have the highest

fiber content).

continued for at least 1 month before effects on bowel function are determined.

The patient should be cautioned that abdominal distention

& flatus may be particularly troublesome in the first few

weeks, particularly with high bran consumption.

PHARMACOLOGIC THERAPY

Laxatives

3 General Classifications:

(1) That causing softening of feces in 1 to 3 days (bulk-

forming laxatives, docusates, and lactulose)

(2) That result in soft or semifluid stool in 6 to 12

hours (bisacodyl and senna)

(3) That causing water evacuation in 1 to 6 hours

(saline cathartics, castor oil, and polyethylene

glycol- electrolyte lavage solution).

Recommendations

The basis for treatment and prevention :

bulk-forming agents + high fiber dietary modifications

For most nonhospitalized persons with acute constipation

infrequent use (less than every few weeks) of most laxative products is acceptable; however, before more

potent laxative / cathartics are used, relatively simple

measures may be tried.

For example : acute constipation may be relieved by the

use of a tap-water enema or a glycerin suppository; if

neither is effective, the use of oral sorbitol, low doses of

bisacodyl or senna, or saline laxatives (e.g., milk of

magnesia) may provide relief.

If laxative treatment is required for longer than 1 week :

consult a physician to determine if there is an underlying cause of constipation that requires treatment

with agents other than laxatives.

Bedridden / geriatric patients / chronic constipation :

first line : bulk-forming laxatives but may be required more potent laxatives (milk of

magnesia & lactulose)

.

In the hospitalized patient without GI disease

(constipation related to general anesthesia &/or opiate

substances) :

Orally or rectally administered laxatives for prompt initiation of a bowel movement (tap-water enema /

glycerin suppository / milk of magnesia)

.

In infants & children

When not related to an underlying disease (neurologic, metabolic / anatomic abnormalities)

the approach to constipation is similar to that in an adult High fiber diet should be emphasized.

Emollient Laxatives (Docusates): surfactant agents, docusate in its various salts

work by facilitating the mixing of aqueous & fatty materials within the intestinal tract may increase water & electrolyte secretion in the small & large bowel.

Result in a softening of stools within 1 - 3 days.

Not effective in treating constipation but are used

mainly to prevent constipation.

Helpful in situations where straining at stool should be avoided (after recovery from myocardial infarction,

with acute perianal disease / after rectal surgery)

Not effective if major causative factors (heavy opiate

use, uncorrected pathology, inadequate dietary fiber)

are not concurrently addressed.

Lubricants: Mineral oil

lubricant laxative in routine use

acts by coating stool and allowing easier passage. It inhibits colonic absorption of water, thereby

increasing stool weight & decreasing stool transit time.

Effect on bowel function : after 2 or 3 days.

Mineral oil is helpful in situations similar to those

suggested for docusates: to maintain a soft stool & avoid

straining for relatively short periods of time (a few days

to 2 weeks).

Mineral oil may be absorbed systemically & cause a

foreign-body reaction in lymphoid tissue.

In debilitated / recumbent patients, mineral oil may be aspirated, causing lipoid pneumonia.

Lactulose and Sorbitol

Lactulose : disaccharide that causes an osmotic

effect retained in the colon.

Generally not recommended as a first-line agent for the

treatment of constipation because it is costly & not

necessarily more effective than milk of magnesia.

as an alternative for acute constipation , useful in elderly.

Occasionally result in flatulence, cramps, diarrhea, & electrolyte imbalances.

Sorbitol : monosaccharide, has been recommended

as a primary agent in the treatment of functional

constipation, as effective as lactulose and much less

expensive.

Saline Cathartics

Composed of relatively poorly absorbed ions

(magnesium, sulfate, phosphate & citrate) produce effects primarily by osmotic action to retain fluid in the

GI tract.

May be given orally or rectally.

A bowel movement may result within a few hours of

oral doses & in 1 hour or less after rectal administration.

Used primarily for acute evacuation of the bowel necessary before diagnostic examinations, after

poisonings & in conjunction with some anthelmintics to

eliminate parasites.

Agents : milk of magnesia (8% suspension of

magnesium hydroxide)

Used occasionally (every few weeks) to treat constipation

in otherwise healthy adults.

Not be used on a routine basis to treat constipation.

Castor Oil

Castor oil is metabolized in the GI tract to an active

compound, ricinoleic acid,

which stimulates secretory processes, decreases glucose absorption & promotes intestinal motility,

(primarily in the small intestine).

Results in a bowel movement within 1 to 3 hours of administration.

Strong purgative action it should not beused for the routine treatment of constipation.

Glycerin

This agent is usually administered as a 3-g suppository

& exerts its effect by osmotic action in the rectum.

Given as suppositories the onset of action is usually less than 30 minutes.

Glycerin is considered a safe laxative, although it

may occasionally cause rectal irritation.

Its use is acceptable on an intermittent basis for

constipation, particularly in children.

Polyethylene Glycol-Electrolyte Lavage Solution

Whole-bowel irrigation with polyethylene glycol-

electrolyte lavage solution popular for colon cleansing before diagnostic procedures / colorectal

operations.

4 liters of this solution is administered over 3 hours to

obtain complete evacuation of the GI tract.

Not recommended for the routine treatment of

constipation & its use should be avoided in patients

with intestinal obstruction.

Lubiprostone

: chloride channel activator that acts locally on the gut

to accelerate genitourinary transit time & delay gastric

emptying.

Approved for chronic idiopathic constipation in adults.

The dose is 24 mg capsule twice daily with food.

Lubiprostone may cause headache, diarrhea & nausea.

Other Agents

Tap-water enemas may be used to treat simple

constipation.

administration of 200 mL of water by enema to an adult often results in a bowel movement within 1.5

hours.

Soapsuds are no longer recommended for usein enemas because their use may result in proctitis or

colitis.

LAKSANSIA / LAXATIVES(Obat pencahar)

Konstipasi kelainan abdominal (waktu melewati usus lambat, reflek pengoso-ngan terganggu) frekuensi defekasi

feses kering & keras.

Hal tsb paling baik diatasi dg diet makan makanan berserat. Obat utk preoperatif colon / rektum.

Preparat : zat pengembang, laksan pemacu, zat pelincir.

1. Zat Pengembang

a. Polisakarida tak tercernakan :

selulose, me-selulose, laktulose

vol intestinal menstimulasi gera-kan peristaltik.

Harus banyak minum utk mencegah penggumpalan isi usus.

Pemakaian dikombinasi dg laksan lain.

b. Zat osmotik :

grm dg ion tg sulit diabsorbsi air tertarik ke lumen usus (abs air

dihambat) bantu defekasi.

2. Laksan Pemacu

Antrakinon, Bisakodil

Meningkatkan motilitas lambung & usus

Tdk utk jangka panjang menyababkan kram abdominal

3. Zat Pelincir

Dioktil sulfosuksinat melunakkan feses

Parafin liquidum melicinkan dinding usus penggunaan kronik akan mengganggu abs vit larut lemak (A,D,