Thioctic acid, also known as alpha-lipoic acid (ALA), was first identified in 1937 by Snell and colleagues and later isolated in 1951 by Reed and his team as a growth factor for specific bacteria. Its initial clinical application began in Germany in 1959 for the treatment of acute poisoning caused by death cap mushrooms. It was later introduced as a therapeutic option for diabetic neuropathy. It is a drug used for the treatment of diabetic polyneuropathy in Germany.
BRAND NAMES
Thioctacid, Thiogamma, Cindella, RejuNEX, Samion, and VITARUHE. For optimal absorption, thioctic acid should be taken on an empty stomach. Take 30 min before meals. Swallow whole, do not chew/crush.
MECHANISM OF ACTION
Thioctic acid, also known as alpha-lipoic acid (ALA), exerts its effects through a multimodal mechanism of action. It acts as a powerful antioxidant by scavenging free radicals and chelating transition metals. Additionally, it helps regenerate other antioxidants such as vitamins C and E, enhances glucose uptake by improving insulin signaling, and reduces inflammation by inhibiting the activation of NF-κB, a key regulator of inflammatory responses.
PHARMACOKINETICS
Absorption
Thioctic acid, also known as alpha-lipoic acid (ALA), is rapidly absorbed after oral administration, but it has low and variable bioavailability. Absorption is primarily influenced by the presence of food and the specific formulation of the supplement.
Distribution
The apparent volume of distribution of thioctic acid is approximately 419 to 471 mL/kg.
Metabolism
The metabolism of thioctic acid involves its synthesis, functioning as a mitochondrial cofactor, absorption from external sources, and degradation into various metabolites. It is synthesized in the mitochondria of plants and animals and is also available through diet or dietary supplements.
Excretion
Approximately 93.2% of the administered radioactivity is excreted in the urine, with only about 2.6% eliminated via the feces.
PHARMACODYNAMICS
Thioctic acid’s pharmacodynamics are mainly based on its strong antioxidant capabilities, including free radical scavenging and metal chelation, which help counteract oxidative stress—a major contributor to diabetic polyneuropathy. Additionally, it supports energy metabolism and improves insulin sensitivity, further contributing to its therapeutic effects.
ADMINISTRATION
Thioctic acid can be administered orally as tablets or capsules or intravenously by injection. Oral dosages are typically taken on an empty stomach for better absorption, while intravenous (IV) administration allows the compound to enter the bloodstream directly.
DOSAGE AND STRENGTH
Oral tablets and capsules are available in a range of strengths to accommodate different dosing needs.
Intravenous (IV) injections: These are administered by a healthcare professional and are available in different strengths.
Topical preparations: Thioctic acid is also an ingredient in cosmetic and skincare products.
DRUG INTERACTIONS
Thioctic acid has several notable drug interactions, primarily involving medications for diabetes, thyroid disorders, cancer, and anticoagulant drugs. Since thioctic acid can affect blood sugar and chelate metal ions, patients on other medications should consult a doctor before taking it.
FOOD INTERACTIONS
The interaction between thioctic acid (alpha-lipoic acid) and food primarily concerns absorption. Taking it with food significantly decreases its bioavailability, so it is recommended to take it on an empty stomach. Thioctic acid is also a metal chelator, meaning it can bind to minerals like iron and calcium, and should not be taken simultaneously with mineral supplements or high-calcium foods. Alcohol can exacerbate neuropathy and worsen thiamine deficiency, so excessive consumption should be avoided.
CONTRAINDICATIONS
Thioctic acid is contraindicated in patients with known hypersensitivity to the drug or its components. Certain pre-existing conditions also require special caution or render the use of thioctic acid unsafe.
SIDE EFFECTS
Most common side effects involve the gastrointestinal system or skin.
Nausea, vomiting, heartburn, and stomach pain.
Diarrhea or, less commonly, constipation.
Headache.
Skin rash and itching.
Dizziness or vertigo.
Less common or rare side effects
Hypoglycemia.
Allergic reactions.
Insulin autoimmune syndrome.
OVER DOSE
Nausea and vomiting.
Abdominal pain or diarrhea.
Headache.
Skin rash or hives.
Hypoglycemia (low blood sugar), which can cause dizziness, sweating, and confusion.
Neurological effects.
Metabolic disturbances.
Heart problems.
Muscle damage.
Blood clotting issues.
TOXICITY
Thioctic acid is a generally safe supplement at typical dosages, but a high-dose overdose can be toxic and potentially fatal. Cases of severe toxicity from acute, high-dose ingestion are rare but well-documented in both adults and children, with symptoms ranging from metabolic to neurologic complications.
