Understanding Laxatives And Diuretics: How Do They Work?

Laxatives and diuretics are two types of medications that induce excretory functions in the body. Laxatives are substances that induce bowel movements or loosen stools, and are generally taken when a person is suffering from constipation. Diuretics, also known as water pills, are substances that promote the production of urine and increase the excretion of water from the body. Both classes of drugs are dangerous and can cause serious damage to the body.

Laxatives induce bowel movements or loosen stools

Laxatives are substances that induce bowel movements or loosen stools. They are typically used to treat constipation and can be bought over the counter in pharmacies, grocery stores, and online.

There are several types of laxatives, including:

• Bulk-forming laxatives: These increase the volume of stools by drawing water into them, making them softer and easier to pass. They are considered the gentlest type of laxative and are usually recommended as the first option. Examples include Metamucil (psyllium husk) and Citrucel (methylcellulose).
• Stool softeners: These agents enable the penetration of fats and water into stools, making them softer and easier to pass. An example is Colace (docusate).
• Lubricants: These coat the colon, making it slick and preventing the absorption of water from the stool, thus keeping it soft. An example is mineral oil.
• Stimulant laxatives: These stimulate the nerves and muscles in the colon, forcing it into motion and moving the stool along. Examples include Dulcolax (bisacodyl) and Fletcher's Laxative (senna).

It is important to follow the instructions on the medication to prevent side effects such as bloating, gas, and stomach cramps. Laxatives should not be used for an extended period as they can cause dependency and worsen constipation. If constipation persists or is chronic, it is recommended to consult a doctor.

Diuretics promote urine production

Diuretics are medications that promote the production of urine and increase the flow of urine. They are also known as water pills. Diuretics increase the excretion of water from the body, through the kidneys. There are several categories of diuretics, and each works in a distinct way. Diuretics are used to treat heart failure, liver cirrhosis, hypertension, influenza, water poisoning, and certain kidney diseases.

High-ceiling/loop diuretics may cause a substantial increase in urine production—up to 20% of the filtered load of salt and water. Loop diuretics, such as furosemide, inhibit the body's ability to reabsorb sodium at the ascending loop in the nephron, which leads to an excretion of water in the urine. Other examples of high-ceiling loop diuretics include ethacrynic acid and torsemide.

Thiazide-type diuretics, such as hydrochlorothiazide, act on the distal convoluted tubule and inhibit the sodium-chloride symporter, leading to a retention of water in the urine. Thiazide diuretics are commonly used to treat mild hypertension.

Carbonic anhydrase inhibitors, such as acetazolamide and methazolamide, inhibit the enzyme carbonic anhydrase, which is found in the proximal convoluted tubule. This results in several effects, including bicarbonate accumulation in the urine and decreased sodium absorption.

Potassium-sparing diuretics do not promote the secretion of potassium into the urine. Examples include spironolactone, amiloride, and triamterene.

Calcium-sparing diuretics result in a relatively low rate of excretion of calcium. Thiazide and potassium-sparing diuretics are considered calcium-sparing diuretics.

Diuretics are widely used medications that play a crucial role in treating various medical conditions by increasing urine production and promoting the removal of excess water, salts, and toxins from the body.

Laxatives are often abused by individuals with eating disorders

Laxatives are commonly misused by individuals with eating disorders, particularly those with bulimia nervosa and the binge-purge subtype of anorexia nervosa. Eating disorder patients constitute the largest group of individuals who misuse laxatives, with up to 75% of those with anorexia and bulimia misusing laxatives. Laxatives are often used to induce diarrhea to feel thinner, lighter, or "empty". They are also used to prevent the absorption of unwanted calories to lose weight or to avoid weight gain after binge eating. However, the effect on nutrient absorption is minimal, with only about a 12% reduction with laxative use.

The abuse of laxatives for weight loss or out of habit poses grave risks. Regular laxative misuse can lead to physical dependence, where the bowel's natural ability to function is diminished, requiring increased doses to achieve the desired effect. This cycle of dependence not only exacerbates constipation when laxative use is stopped but also significantly increases the risk of long-term gastrointestinal damage.

Laxative abuse carries a multitude of risks, affecting nearly every system in the body. One of the most immediate effects is dehydration, as laxatives increase fluid expulsion from the body. This can lead to symptoms such as thirst, dry skin, and fatigue. More dangerously, it can cause electrolyte imbalances, alterations in the levels of essential minerals like potassium, sodium, and magnesium, which are critical for nerve and muscle function. These disruptions can result in arrhythmias, muscle weakness, and even seizures.

Chronic laxative use can lead to a range of gastrointestinal issues, including intestinal nerve damage, laxative dependency for bowel movement, and, in severe cases, ischemic colitis, a condition where blood flow to the colon is reduced, leading to inflammation and ulceration. Additionally, the overuse of stimulant laxatives can wear down the colon's lining, increasing the risk of colon infections and, paradoxically, chronic constipation.

Diuretics are generally considered safe but can cause increased urination and mineral loss

Diuretics are generally considered safe, but they can cause increased urination and mineral loss.

Diuretics, also known as water pills, are substances that promote the production of urine. They increase the excretion of water from the body and are used to treat high blood pressure and heart failure. Diuretics are usually taken orally and are very common, with two diuretic drugs in the top 15 of America's most frequently prescribed drugs. They are generally well tolerated and do not cause bad side effects, but there are some risks.

The usual side effects of diuretics include:

• Increased urination
• Difficulty getting an erection
• Low potassium (unless you're taking a potassium-sparing diuretic)
• Higher blood sugar in people with diabetes
• Unbalanced electrolytes

Diuretics can also cause dehydration if you're taking too high a dose or not drinking enough fluids. They can also lead to constipation if you don't drink enough fluids.

It's important to take diuretics as directed by your healthcare provider and to discuss any concerns or side effects with them. They will monitor your kidney function and potassium levels while you're taking diuretics.

Laxatives can lead to psychological and physiological dependency

Laxatives are commonly misused by patients with eating disorders, particularly those with bulimia nervosa and the binge-purge subtype of anorexia nervosa. The misuse of laxatives is a form of purging, which is a method to remove food from the body to prevent weight gain or promote weight loss. However, this misuse can lead to a range of issues, including dependency on these medications.

Laxative abuse can lead to both psychological and physiological dependency. Individuals with eating disorders may start using laxatives to treat constipation or other gastrointestinal complications caused by their low food intake and dehydration. However, over time, they can become psychologically dependent on laxatives, feeling a profound desire to feel "empty". This psychological dependency is further reinforced by the false belief that laxatives can support rapid weight loss. The misconception stems from the false notion that laxatives can expel calories from the body before the digestive system absorbs them. This belief is incorrect as laxatives act on the large intestine, and by the time food reaches this point, the body has already absorbed most calories.

Physiological or physical dependency on laxatives can also develop over time. The colon may stop reacting to the usual laxative dose, necessitating increasingly larger doses to produce bowel movements. This can lead to a cycle of misuse, as the body becomes dependent on these higher doses for regular bowel movements. This physical dependency can cause severe discomfort and unpleasant symptoms when individuals try to stop using laxatives.

The treatment for laxative dependency involves addressing both the psychological and physical aspects of the dependency. Psychotherapy, such as dialectical behaviour therapy (DBT) or cognitive-behavioural therapy (CBT), is often used to address the underlying psychological issues and change negative thought patterns associated with the misuse. Physically, medical oversight is required to treat electrolyte disturbances and edema formation caused by laxative misuse.

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