Constipation Management Quiz

Community Pharmacy Lecture 4

• Lecture by Dr. Sahar Badr, Associate Professor of Clinical Pharmacy
• Topic: Constipation

Constipation

• Definition: A change in bowel movement frequency from the patient's normal pattern, characterized by passing hard, dry stools with difficulty and infrequent straining.
• Normal Bowel Habit: Ranges from 3 bowel movements per day to 3 per week. Patients experiencing constipation typically complain of difficult-to-pass, hard stools less frequently than usual. A sudden change lasting 2 weeks or longer warrants referral to a GP.
• Causes:
  • Lifestyle: Poor diet (low fiber, insufficient fluid), lack of exercise, and poor bowel habits.
  • Medications: Narcotic analgesics, anticholinergics (e.g., antidepressants or antihistamines), iron supplements, calcium or aluminum antacids, and NSAIDs.
  • Pregnancy: Increased uterus size, hormonal shifts, intake of prenatal vitamins (iron/calcium), reduced physical activity.
  • Systemic Disorders: Intestinal obstruction, tumors, inflammatory bowel disease (IBD), hypothyroidism, irritable bowel syndrome (IBS).
  • Other Factors: Poor diet, lack of exercise, not enough water, poor toilet habits, stress, laxative abuse, bowel cancer, potty training, travelling.

Epidemiology of Constipation

• Age: More prevalent in individuals over 65 years old.
• Gender: Women experience constipation more often than men.

Associated Symptoms

• Often accompanied by abdominal discomfort, bloating, and nausea.
• Severe cases can cause bowel obstruction, evidenced by colicky abdominal pain and vomiting.
• Urgent referral is needed with obstruction symptoms.

Blood in the Stool

• Can be associated with constipation.
• Potential causes: piles (hemorrhoids), anal fissure (small crack in anus skin).
• Associated with low fiber diet.
• Piles may cause discomfort on defecation.
• Anal fissures are usually more painful on defecation.

Diet

• Insufficient dietary fiber is common cause of constipation.
• Changes in diet or lifestyle (e.g., job change, loss of work, retirement, travel) can contribute.
• Inadequate fluid intake is a significant factor.
• Adequate fluid intake is essential for prevention and treatment. Increasing water intake alongside increased fiber is beneficial. The recommended fluid intake for adults is 2.5 liters per day.

Medications (Continued)

• Continuous use of stimulant laxatives may cause a vicious cycle.
• Repeated use may result in loss of muscular activity in the colon (atonic colon).
• This can lead to chronic constipation.
• Many drugs can induce constipation, including:
  • Analgesics and opiates (e.g., dihydrocodeine, codeine)
  • Antacids (e.g., aluminum salts)
  • Anticholinergics (e.g., hyoscine)
  • Anticonvulsants (e.g., phenytoin)
  • Antidepressants (e.g., tricyclics, selective serotonin reuptake inhibitors)
  • Antihistamines (e.g., chlorpheniramine, promethazine)
  • Antihypertensives (e.g., clonidine, methyldopa)
  • Anti-Parkinson agents (e.g., levodopa)
  • Beta-blockers (e.g., propranolol)
  • Iron
  • Laxative abuse
  • Monoamine oxidase inhibitors (MAOIs)
  • Antipsychotics (e.g., chlorpromazine)

When to Refer to a GP

• Changes in bowel habits lasting 2 weeks or longer.
• Abdominal pain, vomiting, or bloating.
• Blood in the stool.
• Prescribed medications suspected of causing symptoms.
• Failure of over-the-counter (OTC) medications to resolve symptoms.

Management

• Treatment Timescale: If one week of treatment does not provide relief, consult a doctor.
• Non-Pharmacological Management:
  • Increase dietary fiber intake.
  • Maintain fluid intake.
  • Incorporate regular exercise.
  • Establish regular bowel training to ensure adequate time for defecation.
  • Diet rich in non-starch polysaccharides (NSPs) and adequate water.
  • Laxative may help in the short term for immediate relief.
• Pharmacological Treatment:
  • Step-wise approach, starting with bulk-forming laxatives.
  • Osmotic laxatives as a second option.
  • Only use stimulant laxatives if previous steps are ineffective or intolerable.
  • Self-care limited to 7 days.

Classification of Laxatives

• Stimulant
• Bulk
• Osmotic
• Emollient
• Saline
• Lubricant

Specific Laxative Types

• Stimulant Laxatives:
  • Mechanism: Alters water and electrolyte transport, stimulating bowel motility.
  • Usage: Recommended when bulk or osmotic laxatives fail.
  • Examples: anthraquinones (e.g., senna, sennosides), diphenylmethane (e.g., bisacodyl).
  • Warnings: Not for prolonged use, potential for overuse, bowel damage, and rectal bleeding, potential discoloration in urine, do not crush tablets.
• Bulk Laxatives:
  • Mechanism: Swells in the gut, absorbing water, softening stool, increasing bulk, stimulating peristalsis.
  • Usage: Suitable when patients can't/won't increase fiber intake.
  • Examples: methylcellulose, psyllium, calcium polycarbophil, wheat dextran.
  • Precautions: Increased fluid intake required to prevent intestinal obstruction, granules mixed with liquid before use.
• Osmotic Laxatives:
  • Mechanism: Creates osmotic gradient pulling water into the intestine, increasing peristalsis.
  • Examples: glycerin suppositories, polyethylene glycol, Epsom salts (magnesium sulfate), lactulose.
  • Warnings: Potential for mild side effects like rectal burning, cramping, diarrhea, flatulence.
• Emollient Laxatives:
  • Mechanism: Allows more water into the stool, creating a softer consistency for easier passage.
  • Examples: Docusate sodium (DOSS), docusate calcium.
  • Precautions: Slow onset.
• Saline Laxatives:
  • Mechanism: Draws water into the colon.
  • Examples: magnesium citrate, magnesium hydroxide, sodium phosphate.
  • Precautions: Potential for abdominal cramping, excessive urination, dehydration, and hypermagnesemia in those with pre-existing kidney conditions. Avoid in those with sodium restrictions.
• Lubricant Laxatives:
  • Mechanism: Increases water retention in the stool.
  • Examples: Mineral oil.
  • Precautions: Potential for aspiration, liver toxicity if used with other laxatives and potential for overdose. Contraindicated for extended use. Not used at bedtime.

Constipation in Specific Populations

• Children: Often due to diet or emotional factors. Dietary advice, and possibly a glycerin suppository, are initial management steps. Medical referral if unsuccessful.
• Elderly: Can be exacerbated by lack of physical activity, tooth problems (causing avoidance of high-fiber foods), and multiple medications. Adequate fluid intake is critical when considering bulk laxatives.
• Pregnancy: Hormonal changes and oral iron contribute to the problem. Avoid stimulant laxatives. Prefer bulk-forming laxatives.

Laxative Abuse

• Two main groups:
  • Those with chronic constipation developing a vicious cycle of constipation and laxative misuse resulting in nerve damage.
  • Those with weight issues, including eating disorders (anorexia nervosa or bulimia), using laxatives to control weight.

General Notes

• The intensity of a laxative effect is dose-dependent.

• Senna can be combined with a stool softener.

• Bisacodyl tablets are enteric-coated and should be swallowed whole.

• Non-standardized products, such as senna pods or cascara, require caution due to unpredictable doses and actions.

• Additional information on symptoms and differential diagnoses of other conditions are not mentioned