Lactic Acid, L-

Dosage for Lactic Acid, L- varies significantly based on the indication and the specific product being used.

For Topical Dermatological Use (e.g., 12% Ammonium Lactate):

• Standard Dose: Apply a thin layer to the affected skin areas twice daily (morning and evening).
• Administration: Rub the cream or lotion in thoroughly until it is no longer visible. It is often most effective when applied to slightly damp skin after bathing.

For Intravenous Fluid Replacement (as Sodium Lactate):

• Standard Dose: The dosage is highly individualized based on the patient's weight, age, clinical condition, and laboratory results (electrolytes and acid-base status).
• Typical Rate: In non-emergency settings, infusion rates may range from 100 mL to 500 mL per hour, but this must be strictly monitored by medical staff.

For Vaginal pH Restoration:

• Standard Dose: Usually one applicator-full (approx. 5g) inserted intravaginally once daily at bedtime for 7 consecutive days.

Lactic Acid, L- is used in pediatric populations, but with caution.

• Topical Use: For children 2 years of age and older, the dosage is generally the same as adults (twice daily application). However, safety and efficacy in children under 2 years old have not been established for all formulations.
• Systemic Use: IV dosages for children are calculated based on body surface area or weight (e.g., mL/kg/hr) and require intensive monitoring in a hospital setting.

Renal Impairment

In patients with severe kidney disease, the elimination of lactate and its associated ions may be impaired. While Lactic Acid, L- itself is metabolized by the liver, the resulting bicarbonate and the fluid volume used in IV administration require functional kidneys for balance. Healthcare providers may reduce the frequency or volume of administration in these patients.

Hepatic Impairment

Since the liver is the primary organ responsible for converting L-lactate into bicarbonate or glucose, patients with hepatic failure or cirrhosis are at a high risk of developing lactic acidosis if given systemic L-lactate. Systemic use is often contraindicated or requires extreme caution in this population.

Elderly Patients

Older adults often have thinner skin and reduced renal/cardiac reserve. For topical use, a lower frequency of application may be initiated to assess skin tolerance. For systemic use, careful monitoring of fluid status is essential to prevent congestive heart failure or pulmonary edema.

Topical Instructions:

• Wash your hands before and after application.
• Avoid applying to broken, cracked, or severely irritated skin unless directed by your doctor.
• Avoid contact with eyes, lips, and mucous membranes.
• Store at room temperature (20°C to 25°C / 68°F to 77°F).

Intravenous Instructions:

• This medication is administered by a healthcare professional in a clinical setting. Do not attempt to self-administer IV fluids.

If you miss a topical dose, apply it as soon as you remember. However, if it is almost time for your next scheduled application, skip the missed dose and return to your regular routine. Do not apply double the amount to make up for a missed dose. For missed doses of vaginal gels, contact your healthcare provider for guidance on whether to extend the treatment duration.

Topical Overdose: Excessive topical application may lead to severe skin redness, peeling, or discomfort. Wash the area with mild soap and water and discontinue use until the irritation subsides.

Systemic Overdose (IV): This can lead to metabolic alkalosis, hypernatremia (high sodium), and fluid overload. Symptoms include confusion, muscle twitching, rapid breathing, and swelling of the extremities. In the event of a suspected IV overdose, the infusion must be stopped immediately, and emergency supportive care (such as diuretics or dialysis) may be required.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance. If you suspect a systemic overdose, call 911 or your local emergency services immediately.

When using topical Lactic Acid, L-, most patients will experience some form of mild localized reaction. These are generally transient and include:

• Stinging or Burning: A sharp, tingling sensation immediately following application, particularly if the skin is dry or has micro-fissures. This usually lasts 5-10 minutes.
• Erythema (Redness): A mild pinkish or reddish hue to the treated area as the acid promotes blood flow and exfoliation.
• Peeling: Visible shedding of the skin, which is often the intended therapeutic effect but can be bothersome if excessive.
• Dryness: Paradoxically, some patients may feel their skin is tighter or drier during the first few days of treatment as the old skin layers are removed.

• Pruritus (Itching): A persistent urge to scratch the treated area.
• Hyperpigmentation: Darkening of the skin, especially in individuals with darker skin tones if the treated area is exposed to the sun without protection.
• Contact Dermatitis: A more significant inflammatory response characterized by small bumps or blisters.

• Severe Skin Maceration: Softening and breaking down of the skin due to prolonged moisture and acid exposure.
• Systemic Absorption Symptoms: In rare cases of application to very large areas of denuded (damaged) skin, patients might experience mild nausea or a metallic taste.
• Ecchymosis: Minor bruising or purple spots at the site of application.

While Lactic Acid, L- is generally safe, certain reactions require urgent medical intervention.

> Warning: Stop taking Lactic Acid, L- and call your doctor immediately if you experience any of these.

1. 1Anaphylaxis: Symptoms include hives, swelling of the face, tongue, or throat, and difficulty breathing. This is most common with Non-Standardized Plant Allergenic Extracts.
2. 2Severe Chemical Burns: If the skin becomes intensely painful, turns white or black, or develops large blisters.
3. 3Metabolic Acidosis/Alkalosis: If receiving IV L-lactate, watch for extreme confusion, lethargy, or rapid, shallow breathing.
4. 4Severe Hypokalemia: If systemic lactate causes a shift in potassium, leading to heart palpitations or extreme muscle weakness.

Prolonged use of topical Lactic Acid, L- can lead to Photosensitivity. Because the medication removes the protective upper layer of dead skin cells, the underlying new skin is significantly more vulnerable to UV damage. This can lead to premature skin aging or an increased risk of sunburn if sun protection is not used consistently. Additionally, chronic use on sensitive areas may lead to a thinning of the epidermis (skin atrophy), though this is less common than with topical steroids.

No FDA black box warnings currently exist for Lactic Acid, L- in its standard topical or IV forms. However, it is important to note that L-lactate is a major component in many complex biological products, and users should always refer to the specific prescribing information for the final drug product (e.g., specific allergenic extracts or specialized IV solutions).

Report any unusual symptoms to your healthcare provider. You may also report side effects to the FDA at 1-800-FDA-1088.

Lactic Acid, L- is a potent chemical agent that must be used with respect for its ability to alter tissue pH and systemic acid-base balance. Patients must be aware that while it is a 'natural' substance found in the body, pharmaceutical concentrations are much higher and can cause significant tissue irritation or systemic electrolyte shifts if used incorrectly.

No FDA black box warnings for Lactic Acid, L-.

Allergic Reactions / Anaphylaxis Risk

This is particularly relevant for Lactic Acid, L- when it is a component of Non-Standardized Plant Allergenic Extracts. Patients undergoing allergy testing or immunotherapy must be monitored for at least 30 minutes following administration to ensure they do not develop a systemic allergic reaction. Signs of anaphylaxis include sudden drop in blood pressure, wheezing, and generalized urticaria (hives).

Sun Sensitivity (Photosensitivity)

Lactic Acid, L- is an alpha-hydroxy acid (AHA) that may increase your skin's sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for one week afterwards.

Organ-Specific Risks

• Hepatotoxicity: While L-lactate doesn't cause liver damage, a damaged liver cannot process L-lactate. Systemic administration in patients with liver failure can lead to life-threatening lactic acidosis.
• Nephrotoxicity: Patients with impaired renal function may struggle to excrete the metabolites associated with L-lactate therapy, leading to fluid and electrolyte imbalances.

For patients using topical Lactic Acid, L-, monitoring is primarily visual and based on patient comfort. However, for those receiving systemic (IV) L-lactate, the following labs are typically required:

• Serum Electrolytes: Specifically sodium, potassium, and chloride.
• Arterial Blood Gases (ABGs): To monitor pH, pCO2, and bicarbonate levels.
• Serum Lactate Levels: To ensure the body is successfully metabolizing the infused lactate.
• Liver Function Tests (LFTs): To assess the organ's capacity for lactate metabolism.

Topical use of Lactic Acid, L- does not typically affect the ability to drive or operate machinery. However, systemic administration or severe reactions to allergenic extracts may cause dizziness or lethargy. If you feel lightheaded or confused, do not drive and contact your healthcare provider.

Alcohol consumption should be limited when receiving systemic L-lactate. Alcohol can interfere with the liver's ability to undergo gluconeogenesis and process lactate, potentially increasing the risk of lactic acidosis. For topical use, alcohol has no known direct interaction, though it may contribute to skin dehydration.

There is no known withdrawal syndrome associated with Lactic Acid, L-. However, stopping topical treatment for hyperkeratotic conditions will likely result in the return of dry, scaly skin within a few days to weeks. For IV therapy, discontinuation is managed by a physician based on the stabilization of the patient's acid-base status.

> Important: Discuss all your medical conditions with your healthcare provider before starting Lactic Acid, L-.

There are few absolute contraindications for Lactic Acid, L-, but the following should be avoided:

• Strong Alkaline Cleansers (Topical): Using highly basic soaps or cleansers immediately before or after Lactic Acid, L- can neutralize the acid, rendering it ineffective and potentially causing a localized exothermic (heat-releasing) reaction that irritates the skin.
• Specific IV Admixtures: L-lactate solutions (like Lactated Ringer's) are incompatible with certain drugs like Ceftriaxone in neonates, as it can lead to the formation of life-threatening precipitates in the lungs and kidneys.

• Retinoids (Tretinoin, Adapalene, Isotretinoin): Combining topical Lactic Acid, L- with retinoids can significantly increase the risk of severe skin irritation, redness, and peeling. If used together, they should typically be applied at different times of the day (e.g., Lactic Acid in the morning and Retinoid at night).
• Corticosteroids: Systemic corticosteroids can affect glucose metabolism and electrolyte balance, which may complicate the monitoring of patients receiving IV L-lactate.

• Salicylic Acid: Another keratolytic agent. Using both simultaneously can lead to excessive skin thinning and irritation.
• Diuretics (Furosemide, Hydrochlorothiazide): These medications can affect potassium and sodium levels, which may interact with the electrolyte-balancing effects of systemic L-lactate.

There are no significant food interactions for topical Lactic Acid, L-. For systemic use, a high-carbohydrate diet may slightly alter the rate of gluconeogenesis from lactate, but this is rarely clinically significant in a hospital setting.

• Vitamin C (Ascorbic Acid): When applied topically, Vitamin C is also an acid. Using it with Lactic Acid, L- may increase the risk of skin irritation.
• St. John’s Wort: Because St. John's Wort can increase photosensitivity, it may compound the sun-sensitivity risk associated with Lactic Acid, L-.

Lactic Acid, L- can interfere with the following laboratory measurements:

• Serum Lactate: Obviously, exogenous administration will raise these levels.
• Urinary pH: Systemic administration will typically increase (alkalize) the pH of the urine.
• Glucose: Because lactate is converted to glucose in the liver, blood sugar levels may rise slightly in diabetic patients receiving IV lactate.

For each major interaction, the mechanism usually involves Pharmacodynamic Synergy (two drugs doing the same thing to the skin) or Metabolic Competition (in the liver). Management typically involves spacing out applications or adjusting the dosage of the secondary medication.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.

Lactic Acid, L- must NEVER be used in the following circumstances:

1. 1Known Hypersensitivity: If you have had a previous severe allergic reaction (anaphylaxis or severe contact dermatitis) to Lactic Acid, L- or any component of the formulation.
2. 2Lactic Acidosis: Systemic administration is strictly contraindicated in patients who already have elevated serum lactate levels or a pH imbalance favoring acidosis.
3. 3Severe Hepatic Failure: Because the liver cannot process the lactate, administration can lead to toxic accumulation.
4. 4Ceftriaxone use in Neonates: Due to the risk of fatal calcium-ceftriaxone precipitates if using lactate solutions containing calcium.

Conditions requiring careful risk-benefit analysis include:

• Active Sunburn: Applying Lactic Acid, L- to sunburnt skin will cause intense pain and further damage the skin barrier.
• Open Wounds or Eczema Flare-ups: The acidic nature of the product can cause extreme irritation and delay healing in raw, weeping skin.
• Congestive Heart Failure (CHF): For systemic use, the sodium load associated with sodium lactate can worsen fluid retention and trigger a CHF exacerbation.
• Diabetes Mellitus: Systemic lactate can be converted to glucose, potentially complicating blood sugar management.

Patients who are sensitive to other Alpha-Hydroxy Acids (AHAs), such as Glycolic Acid, Malic Acid, or Citric Acid, are at a higher risk of reacting poorly to Lactic Acid, L-. While not a true cross-allergy in the immunological sense, the irritant potential is similar across this class of compounds.

> Important: Your healthcare provider will evaluate your complete medical history before prescribing Lactic Acid, L-.

FDA Pregnancy Category: Most topical Lactic Acid, L- products are categorized as Category C.

• Topical Use: Animal reproduction studies have not been conducted. It is also not known whether Lactic Acid, L- can cause fetal harm when applied topically to a pregnant woman. However, because systemic absorption is minimal, it is generally considered safe for use during pregnancy if clearly needed and used on small surface areas.
• Systemic Use: IV L-lactate should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, particularly regarding the maintenance of maternal acid-base balance during labor or surgery.

It is not known whether Lactic Acid, L- is excreted in human milk following topical application. However, as it is a natural constituent of human milk and systemic absorption from the skin is low, it is unlikely to pose a risk to the nursing infant. Care should be taken to avoid applying the cream to the breast area to prevent the infant from direct oral ingestion or skin contact.

Lactic Acid, L- is commonly used to treat ichthyosis in children. However, pediatric patients have a higher surface-area-to-body-mass ratio, which may increase the risk of systemic absorption.

• Safety: Use in children under 2 years of age should be under strict medical supervision.
• Monitoring: Parents should monitor for signs of excessive irritation or systemic malaise.

Elderly patients are more likely to have dry skin but also have a higher prevalence of renal and hepatic impairment.

• Topical: Start with once-daily application to ensure the skin barrier can tolerate the acid.
• Systemic: Close monitoring of cardiac and renal function is required to prevent fluid overload, as the elderly are more susceptible to the sodium load found in many lactate-containing IV fluids.

In patients with a GFR (Glomerular Filtration Rate) below 30 mL/min, the use of systemic L-lactate must be carefully managed. While the liver processes the lactate, the resulting bicarbonate and the fluid volume require renal clearance. Dialysis patients may require specific adjustments to their dialysate if lactate is being used as a buffering agent.

Lactic Acid, L- is relatively contraindicated in severe hepatic impairment (Child-Pugh Class C). In milder cases, it may be used with frequent monitoring of blood pH and lactate levels to ensure the liver is not being overwhelmed.

> Important: Special populations require individualized medical assessment.

Lactic Acid, L- is a 3-carbon carboxylic acid. In dermatology, its primary mechanism is as a keratolytic. It acts by increasing the hydration of the skin and reducing the pH of the stratum corneum, which interferes with the cellular adhesion of corneocytes. This leads to a softening of the skin and the subsequent shedding of hyperkeratotic scales.

Systemically, L-lactate is a substrate for the enzyme Lactate Dehydrogenase (LDH). In an aerobic environment, L-lactate is converted to pyruvate, which enters the mitochondria and is oxidized to CO2 and water through the citric acid cycle. This process generates ATP and consumes hydrogen ions, which is the basis for its use as an alkalizing agent.

• Onset of Action: Topical effects on skin hydration can be seen within 24–48 hours, but full keratolytic effects often take 1–2 weeks of consistent use. Systemic alkalizing effects begin within minutes of starting an IV infusion.
• Duration of Effect: Topical effects last for approximately 12–24 hours per application. Systemic effects persist as long as the infusion continues and for a short period (1–2 hours) after discontinuation as the lactate is metabolized.
• Tolerance: There is no known pharmacological tolerance to Lactic Acid, L-, although the skin may become 'accustomed' to the acid, requiring a slightly higher concentration over many months for the same level of exfoliation.

| Parameter | Value |

|---|---|

| Bioavailability | <10% (Topical); 100% (IV) |

| Protein Binding | Negligible |

| Half-life | 15–30 minutes (Systemic) |

| Tmax | 1–2 hours (Topical); Immediate (IV) |

| Metabolism | Hepatic (LDH enzyme) |

| Excretion | Renal (<5%); Pulmonary (as CO2) |

• Molecular Formula: C3H6O3
• Molecular Weight: 90.08 g/mol
• Solubility: Highly soluble in water and ethanol.
• Structure: A chiral molecule with a hydroxyl group on the alpha-carbon. The 'L' designation refers to the Levorotatory configuration, which is the biologically active form in humans.

Lactic Acid, L- is classified as an Alpha-Hydroxy Acid (AHA) and a Keratolytic. In the context of the EPC data, it is a Non-Standardized Plant Allergenic Extract [EPC] component. It is related to other AHAs like Glycolic Acid and Mandelic Acid, but is unique due to its endogenous (natural to the body) status.