CONSTIPATION

DEFINITION

Constipation is a condition that is characterised by the passing of hard, dry stool in a relatively painful manner where bowel motions are irregular or infrequent with respect  to ones normal bowel habits. As the nature of bowel habits varies greatly from individual to the next it is important to understand that there is no fixed definition of this condition, however the normal frequency of unassisted bowel evacuation may be between three movements in any one day to three movements in any week.

BOWEL HABITS

The fact that laxatives are often abused leads us to believe that may people still feel that the passing of stools daily is necessary to maintain ones good health. This Is in fact incorrect as the ‘normal’ range for bowel movements may vary from as high as three movements In one day to as low as three movements in a week. Thus as pharmacists it is an important role for us to reassure the patient and educate them as to what is the norm.

CAUSE OF CONSTIPATION

The cause of constipation in any one individual may be as the different type of lifestyles each person leads, hence is would be an extremely time consuming task to catalogue all the causes. For the purpose of this training module however we will be mainly concerned with drugs which cause constipation, questions to ask a patient about their condition, the types of products available to treat the symptoms and when we must seek further medical assistance.

DRUGS WHICH CAUSE CONSTIPATION

 Due to the almost unlimited numbers and types of medications we as a community, it is not difficult to understand why so many prescribed and O.T.C products can cause constipation. Many drugs used can induce a bout of constipation whilst on the other hand the abuse of laxatives can also have a similar effect. The table below list some common medications which may cause constipation :

                            Analgesics and opiates                      codeine, dihydrocodeine

                            Antacids                                             aluminium salts

                            Anticholinergic                                 hyoscine

                            Antidepressants                                 amitriptyline

                            Antihistamines                                   promethazine, chlorpheniramine

                            Antihypertensives                              clonidine, prazosin, methyldopa

                            Anti-Parkinson agents                        levodopa

                            Beta blockers                                     propranolol

                            Diuretics                                             bendrofluazide

                            Iron                                                    ferrous sulphate

                            MAOI’s                                             phenelzine

                            Psychotropic                                      chlorpromazine

                            Laxative abuse                                   stimulant laxatives

TREATMENT OF CONSTIPATION

Most forms of constipation whether caused by dietary change or medication involvement are relatively easy to treat just by increasing the amount  of clear fluid, fibre intake and exercise in ones normal routine. Mild laxatives may also be added in the recommended amount  in the short term for more stubborn cases. Generally we can classify the products we use to treat this condition as followed.

LAXATIVES (stimulants): These relieve constipation by increasing peristalsis and should only be used starting at lower dosages, moving up only when necessary. They generally work within 6 to 12 hours and should not be used for more than 1 week before referral. Example include products containing senna bisacodyl and phenolphthalein.

LAXATIVES (bulk): Bulk laxatives are by far the safest and best first line treatment of constipation as they most closely resemble the normal physiological mechanisms involved in bowel evacuation. These various products work by swelling in the gut thus increasing faecal mass and bacterial infiltration so that the remaining stool exerts its own positive effects on peristalsis. It is important to know that this effect may take several days and the consumption of generous amounts of clear fluids is also essential to avoid intestinal obstruction. Examples include: ispaghula, methylcellulose, sterculia, bran, psyllium.

LAXATIVES (lubricant): These agents coat and soften the faeces to enable a smooth passage through the intestinal system. They are very effective but if used for long periods may impair the absorption of the fat soluble vitamins A,D,E and K. Example include liquid paraffin emulsion and docusate.

LAXATIVES (osmotic) and Saline Cathartics: These agents are generally used to prepare a patient for a diagnostic bowel procedure, and work by increasing  osmotic pressure in the intestine thus drawing water into the area which in turn increases peristalsis.

These products exert their effect in about 3 hours however repeated doses could cause dehydration and fluid electrolyte imbalances. Care also needs to be taken when used in patients on blood pressure tablets or other heart failure candidates.

CONSTIPATION IN CHILDREN AND THE ELDERLY:

The cause of constipation in children may also be a direct result of a change in diet, emotional disturbance or the introduction of new medicines. Simple advice about increasing fibre, fluid intake or the use of a mild laxatives may be all that is needed for relief, where more persistent cases need to be referred

Similarly the elderly population may experience more prolonged periods of constipation as they are less mobile and are generally on some sort of medication which may influence their condition. The use of bulk laxatives is the first line of choice for this group of patients, however counselling on adequate fluid intake is essential to avoid any intestinal obstruction occurring.

PROPRIETARY PRODUCTS:

Infants up to 2 years                           Brauer Stomach Calm (up to 12 months)

                                                            777 Formula GIT

Coloxyl drops (chronic)

                                                            Glycerine suppositories

                                                            Nucolox

Children’s and Adults                                    Coloxyl & Senna

M/Tree Organo Boweldigest

Quick Fibre Plus

Nucolox

                                                            777 Formula GIT

                                                            Brauer Elimitona