Aloe

Dosage for Aloe varies significantly based on the intended use and the specific formulation. Because many products are marketed as dietary supplements, standardized dosing is often unavailable.

• Topical Application (Burns/Skin Irritation): Apply a liberal layer of 0.5% to 100% Aloe vera gel to the affected area three to five times daily. For psoriasis, creams containing 0.5% Aloe extract applied three times daily have been used in clinical trials.
• Oral Laxative (Historical Context): When previously used as an OTC laxative, the typical dose was 50 to 200 mg of Aloe latex (providing approximately 10 to 30 mg of aloin) taken once daily at bedtime. Note: Oral use for more than 7-10 consecutive days is strongly discouraged by healthcare professionals.
• Oral Juice: For general digestive health, some manufacturers suggest 2 to 4 ounces daily of decolorized (purified) Aloe vera juice. However, clinical evidence for this use is limited.

• Topical Use: Generally considered safe for children when applied to minor burns or irritations. However, a patch test is recommended to rule out hypersensitivity.
• Oral Use: NOT recommended for children under the age of 12. The risk of severe dehydration and electrolyte imbalance is significantly higher in pediatric populations. Stimulant laxatives can lead to dependency and interfere with normal bowel development.

Renal Impairment

Oral Aloe should be avoided in patients with renal impairment. The potential for electrolyte shifts (specifically hypokalemia) can exacerbate kidney dysfunction and increase the risk of cardiac complications.

Hepatic Impairment

There are no specific dosage adjustments provided for hepatic impairment; however, rare cases of hepatotoxicity have been linked to oral Aloe supplements. Use with extreme caution in patients with underlying liver disease.

Elderly Patients

Elderly patients are at a higher risk for electrolyte depletion and dehydration. If oral Aloe is used, it should be at the lowest effective dose for the shortest possible duration. Monitoring of potassium levels is advised.

• Topical: Ensure the skin is clean before application. If using for a burn, do not apply to third-degree burns or deep puncture wounds without medical supervision.
• Oral (Capsules/Tablets): Take with a full glass of water. It is usually best taken at bedtime as the laxative effect typically occurs 6 to 12 hours after ingestion.
• Storage: Store Aloe products in a cool, dry place. Many pure Aloe gels should be refrigerated after opening to prevent microbial growth, as they often lack strong preservatives.

If you miss a dose of Aloe, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not double the dose to catch up, especially with oral formulations, as this increases the risk of severe abdominal cramping and diarrhea.

Signs of an oral Aloe overdose include:

• Severe abdominal pain and cramping.
• Profuse, watery diarrhea.
• Dehydration (thirst, dry mouth, dizziness).
• Blood in the stool (hematochezia).
• Kidney pain or decreased urine output.

In the event of an overdose, seek emergency medical attention immediately. Treatment is primarily supportive, focusing on fluid and electrolyte replacement.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or start oral Aloe without medical guidance, particularly if you have underlying health conditions.

When used topically, Aloe is generally well-tolerated. However, common reactions include:

• Skin Redness (Erythema): A mild, temporary reddening of the skin at the application site.
• Stinging or Burning: A transient sensation immediately following application, particularly on broken or sensitive skin.
• Itching (Pruritus): Mild irritation as the gel dries on the skin surface.

When taken orally, common side effects include:

• Abdominal Cramping: Often described as a sharp, twisting sensation in the mid-to-lower abdomen.
• Diarrhea: Loose, watery stools which may occur suddenly.
• Urine Discoloration: A harmless change in urine color to red or yellowish-brown due to anthraquinone excretion.

• Contact Dermatitis: A localized allergic reaction characterized by a rash, swelling, or blisters.
• Nausea: A feeling of sickness in the stomach, sometimes following oral ingestion of the bitter latex.
• Dependency: With repeated oral use, the bowel may become dependent on the stimulant effect, leading to worsened constipation upon discontinuation.

• Hepatotoxicity: Rare reports of liver inflammation (hepatitis) associated with long-term oral use of Aloe supplements.
• Hypokalemia: Critically low potassium levels in the blood, which can lead to muscle weakness and heart rhythm disturbances.
• Nephrotoxicity: Potential for kidney damage or acute kidney injury, particularly in the context of dehydration from chronic diarrhea.

> Warning: Stop taking Aloe and call your doctor immediately if you experience any of these:

• Anaphylaxis: Signs include hives, difficulty breathing, swelling of the face, lips, or throat. This is a medical emergency.
• Severe Electrolyte Imbalance: Symptoms include extreme muscle weakness, irregular heartbeat (arrhythmia), confusion, or seizures.
• Melena or Hematochezia: The presence of black, tarry stools or bright red blood in the stool, indicating gastrointestinal bleeding.
• Severe Dehydration: Inability to keep down fluids, sunken eyes, extreme lethargy, or lack of urination.

• Melanosis Coli: This is a benign but significant condition where the lining of the colon develops a dark, leopard-like pigmentation. It is caused by the chronic use of anthraquinone-containing laxatives like Aloe. While usually reversible upon discontinuation, it is a marker of chronic laxative abuse.
• Colorectal Cancer Risk: There has been ongoing scientific debate regarding the carcinogenic potential of aloin. The National Toxicology Program (NTP) found evidence of carcinogenic activity in male and female rats (specifically adenomas and carcinomas of the large intestine) following high-dose oral exposure to non-decolorized whole leaf Aloe vera extract. While human data is not definitive, long-term oral use is discouraged.

No FDA black box warnings currently exist for Aloe, primarily because it is not an FDA-approved prescription drug. However, the FDA has issued strong safety communications regarding the lack of safety data for its use as an OTC laxative.

Report any unusual symptoms to your healthcare provider. If you suspect a serious reaction, contact the FDA MedWatch program.

Aloe is not a benign substance, particularly when ingested. Patients must distinguish between topical Aloe gel (generally safe) and oral Aloe latex (potentially toxic). Oral Aloe should never be used as a long-term solution for constipation. If you have a known allergy to plants in the Liliaceae family (such as onions, garlic, and tulips), you are at a higher risk of an allergic reaction to Aloe.

No FDA black box warnings for Aloe. However, the regulatory removal of Aloe from the OTC laxative category in 2002 serves as a significant regulatory warning regarding its safety profile for internal use.

• Allergic Reactions / Anaphylaxis Risk: While rare, systemic allergic reactions can occur. Always perform a small patch test before applying Aloe to large areas of the body.
• Gastrointestinal Disorders: Aloe should not be used by individuals with inflammatory bowel disease (IBD), such as Crohn's disease or ulcerative colitis, as it can severely irritate the intestinal lining and worsen the condition.
• Renal Toxicity: Chronic ingestion of Aloe latex has been linked to kidney failure. Patients with pre-existing kidney disease must avoid oral Aloe.
• Electrolyte Depletion: The stimulant laxative effect can lead to a rapid loss of potassium and sodium. This is particularly dangerous for patients with heart disease or those taking medications that affect heart rhythm.

If a healthcare provider supervises the use of oral Aloe, the following monitoring may be required:

• Serum Electrolytes: Regular checks of potassium, sodium, and chloride levels.
• Renal Function Tests: Monitoring of Creatinine and Blood Urea Nitrogen (BUN).
• Liver Function Tests (LFTs): To screen for rare cases of drug-induced liver injury.
• Colonoscopy: In cases of chronic use, to check for Melanosis coli.

Topical Aloe does not affect the ability to drive. However, oral Aloe may cause sudden, urgent bowel movements or abdominal cramping that could distract a driver or operator of heavy machinery.

Alcohol can exacerbate the dehydrating effects of oral Aloe. Combining the two may increase the risk of electrolyte imbalances and gastrointestinal irritation.

If Aloe has been used orally for an extended period, it should be discontinued under medical supervision. Abrupt cessation may lead to "rebound constipation" where the bowels are unable to function normally without the stimulant. A gradual tapering and an increase in dietary fiber and fluid intake are typically recommended.

> Important: Discuss all your medical conditions, especially gastrointestinal or renal issues, with your healthcare provider before starting Aloe.

• Digoxin (Lanoxin): Aloe-induced potassium depletion significantly increases the risk of digoxin toxicity. Low potassium levels make the heart muscle more sensitive to digoxin, which can lead to life-threatening cardiac arrhythmias (irregular heartbeats).
• Other Stimulant Laxatives (e.g., Senna, Bisacodyl): Combining Aloe with other stimulant laxatives can lead to severe dehydration, profound electrolyte loss, and permanent damage to the bowel's enteric nervous system.

• Diuretics (e.g., Furosemide, Hydrochlorothiazide): These "water pills" also lower potassium levels. Using them with oral Aloe creates a synergistic effect that can lead to severe hypokalemia.
• Warfarin (Coumadin): Aloe may have an antiplatelet effect and can also cause diarrhea, which reduces the absorption of Vitamin K. This can enhance the blood-thinning effects of Warfarin, increasing the risk of bruising and bleeding.
• Corticosteroids (e.g., Prednisone): Long-term use of steroids can deplete potassium. Combined with Aloe, the risk of electrolyte imbalance is significantly heightened.

• Antidiabetic Drugs (e.g., Insulin, Metformin, Glyburide): Some studies suggest that oral Aloe may lower blood glucose levels. When taken with diabetes medications, it may increase the risk of hypoglycemia (low blood sugar). Patients should monitor their blood sugar closely.
• Sevoflurane: There is a theoretical risk that Aloe may increase bleeding during surgery when combined with certain inhaled anesthetics. Discontinue Aloe at least two weeks before scheduled surgery.

• Licorice (Natural): Natural licorice can also lower potassium levels, compounding the risk of hypokalemia when used with Aloe.
• Alcohol: Increases the risk of dehydration and GI irritation.

• Horsetail: This herb has diuretic properties and can further deplete potassium.
• Stimulant Herbs: Herbs like Cascara Sagrada or Rhubarb root should not be combined with Aloe due to additive laxative effects.

• Urine Glucose/Protein Tests: Aloe metabolites can cause false-positive results in certain dipstick urine tests due to the reddish discoloration of the urine.
• Stool Guaiac Tests: Aloe may interfere with tests for occult (hidden) blood in the stool.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. The risk of interaction is highest with oral Aloe latex.

Aloe must NEVER be used orally in the following conditions:

• Intestinal Obstruction or Stenosis: Stimulating a blocked bowel can lead to perforation (a hole in the intestine), which is a surgical emergency.
• Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis involve an already inflamed gut; Aloe's irritant effect can cause severe flares and bleeding.
• Appendicitis: Aloe can worsen the inflammation and increase the risk of the appendix rupturing.
• Severe Renal Disease: The inability of the kidneys to manage electrolyte shifts makes Aloe extremely dangerous.
• Pregnancy: Oral Aloe latex is a known emmenagogue (stimulates blood flow to the pelvic area) and abortifacient (can cause miscarriage) due to its ability to stimulate uterine contractions.
• Children under 12: Due to the high risk of severe dehydration and electrolyte imbalance.

• Diabetes: Requires careful monitoring of blood glucose levels due to potential hypoglycemic effects.
• Hemorrhoids: The irritant effect of the anthraquinones can cause increased pain and inflammation in the rectal area during bowel movements.
• History of Cardiac Arrhythmia: Any condition sensitive to potassium levels requires extreme caution.

Patients with known hypersensitivity to other members of the Liliaceae (Lily) family may experience cross-allergic reactions. This includes plants such as:

• Onions and Garlic
• Tulips
• Hyacinths
• Asparagus

> Important: Your healthcare provider will evaluate your complete medical history, including any history of bowel disease or allergies, before recommending the use of Aloe.

• Topical Use: Generally considered safe for use on the skin during pregnancy for minor irritations.
• Oral Use: STRICTLY CONTRAINDICATED. Aloe latex contains anthraquinones which can stimulate uterine contractions, potentially leading to premature labor or miscarriage. There is also a theoretical risk of teratogenicity (birth defects) based on animal studies of high-dose anthraquinones.

• Topical Use: Safe, but ensure the gel is not applied to the nipple area where the infant might ingest it.
• Oral Use: NOT RECOMMENDED. Anthraquinone metabolites (like aloe-emodin) can pass into breast milk and may cause diarrhea and abdominal distress in the nursing infant.

• Topical: Safe for minor skin issues in children, provided there is no allergy.
• Oral: Not approved for children under 12. The risk of "lazy bowel syndrome" and severe electrolyte loss is a major concern in developing children.

Elderly patients are more susceptible to the adverse effects of stimulant laxatives.

• Fall Risk: Severe diarrhea and subsequent dehydration can lead to orthostatic hypotension (a drop in blood pressure upon standing), increasing the risk of falls.
• Cardiac Concerns: Older adults are often taking medications like Digoxin or diuretics, making Aloe-induced potassium loss particularly dangerous.

Patients with a glomerular filtration rate (GFR) below 30 mL/min should avoid oral Aloe entirely. The risk of acute kidney injury (AKI) is increased in these patients due to the potential for severe volume depletion.

While not a primary route of elimination, the liver processes absorbed Aloe metabolites. Patients with Child-Pugh Class B or C cirrhosis should avoid oral Aloe supplements due to rare reports of hepatotoxicity and the risk of exacerbating hepatic encephalopathy if dehydration occurs.

> Important: Special populations require individualized medical assessment. Always consult a specialist before using Aloe if you are pregnant, nursing, or have chronic health conditions.

Aloe's pharmacology is divided into its polysaccharide-mediated effects (healing) and its anthraquinone-mediated effects (laxative). The polysaccharide acemannan binds to mannose receptors on macrophages, enhancing their phagocytic activity and the production of growth factors. Topically, the enzyme bradykinase breaks down bradykinin, a chemical mediator of pain and inflammation. Orally, aloin is converted by colonic bacteria into aloe-emodin, which acts directly on the intestinal mucosa to stimulate chloride secretion and inhibit water reabsorption.

• Onset of Action (Topical): Immediate cooling effect; healing benefits observed over 48-72 hours.
• Onset of Action (Oral): 6 to 12 hours (the time required for the substance to reach the colon and undergo bacterial activation).
• Duration of Effect: 24 to 48 hours for oral doses.
• Tolerance: Chronic use leads to tolerance, requiring higher doses to achieve the same laxative effect, eventually leading to colonic atony (loss of muscle tone).

| Parameter | Value |

|---|---|

| Bioavailability | Low (Oral glycosides); Variable (Topical) |

| Protein Binding | Unknown in humans |

| Half-life | ~3-6 hours (for active metabolites) |

| Tmax | 8-12 hours (for systemic absorption of metabolites) |

| Metabolism | Gut bacteria (primary); Liver (secondary) |

| Excretion | Fecal (primary); Renal (secondary) |

• Main Constituents: Aloin A and B, Aloe-emodin, Acemannan, Salicylic acid.
• Molecular Formula: C21H22O9 (Aloin).
• Solubility: Gel is water-soluble; latex components are soluble in alcohol and hot water.
• Structure: Anthraquinone glycoside (Aloin) consisting of an anthrone ring attached to a sugar moiety.

Aloe belongs to the Non-Standardized Plant Allergenic Extract [EPC] class and is functionally a Stimulant Laxative when used orally. It shares characteristics with other anthraquinone-containing plants like Senna and Cascara Sagrada.