Triamcinolone acetonide

BRAND NAMES

Aristocort: A brand name for oral tablets and topical creams. 

Kenalog: Available as a topical cream, ointment, and injectable form. 

Nasacort: A nasal spray brand used for allergy symptoms. 

Triderm: A brand name that can be found in topical cream formulations. 

Triamcot / Acetocot / Triam-A: Brands for the injectable forms of triamcinolone acetonide.

MECHANISM OF ACTION

Triamcinolone, like other corticosteroids, exerts its anti-inflammatory effects through multiple mechanisms. It inhibits the enzyme phospholipase A2 located on cell membranes, which prevents the breakdown of lysosomal membranes in leukocytes. This action stops the release of arachidonic acid, a key precursor in the inflammatory process. As a result, the production of cyclooxygenase (COX) and lipoxygenase (LOX) enzymes is reduced, leading to decreased synthesis of prostaglandins and leukotrienes, both of which are major mediators of inflammation.

PHARMACOKENITICS

Absorption:

The systemic absorption of triamcinolone acetonide varies widely depending on the formulation and route of administration. When given intravenously, it is absorbed completely and rapidly. Oral administration results in nearly 90% absorption, while topical applications typically lead to variable and often limited systemic absorption.

Distribution:

The duration of action for triamcinolone varies based on the route of administration. When given intravenously, it has a reported volume of distribution of 103 liters. In contrast, its oral bioavailability is approximately 23%, reflecting limited absorption into systemic circulation when taken by mouth.

Metabolism:

Triamcinolone acetonide is mainly broken down in the liver by the cytochrome P450 (CYP) enzyme system, with the CYP3A4 isoenzyme playing a key role. It is converted into inactive metabolites, though the specific metabolic processes and resulting metabolites may differ slightly between species.

Excretion:

After being metabolized in the liver by the CYP3A4 enzyme system, triamcinolone acetonide is eliminated from the body through both the kidneys (urine) and the gastrointestinal tract (feces). Although a small portion of the unchanged drug may be excreted, the majority is removed as metabolites. Most of the administered dose is cleared from the body within 24 to 72 hours after administration.

PHARMACODYNAMICS

Triamcinolone acetonide primarily works by binding to glucocorticoid receptors, which triggers a series of actions that suppress inflammation. This includes reducing the production of inflammatory mediators such as prostaglandins and leukotrienes, inhibiting the movement of immune cells to affected areas, and decreasing the expression of pro-inflammatory cytokines. As a result, it helps alleviate symptoms like swelling (edema), redness (erythema), and itching (pruritus), making it effective in treating various inflammatory and allergic disorders.

ADMINISTRATION

Triamcinolone acetonide is a corticosteroid administered in various forms, including injections, topical creams, ointments, dental paste, and nasal sprays. The administration method depends on the condition being treated.

DOSAGE AND STRENGTH

Triamcinolone acetonide is available in various strengths depending on the dosage form. For topical use, common strengths include 0.025%, 0.1%, 0.5%, and 0.05% in creams, ointments, lotions, and sprays. Dosage typically involves applying the medication two to four times daily for creams, lotions, and ointments, and three to four times daily for the aerosol spray. Always follow your doctor’s instructions and do not change your dose without medical guidance.

DRUG INTERACTION

Triamcinolone acetonide may interact with several medications, potentially affecting its effectiveness or increasing the risk of side effects. Key interactions include:

• CYP3A4 inhibitors (e.g., ritonavir, ketoconazole), which can elevate triamcinolone levels and heighten the risk of adverse effects.

• Antidiabetic medications, as triamcinolone may raise blood glucose levels, possibly requiring adjustments to insulin or oral diabetes drugs.

• Anticoagulants like warfarin, where co-administration may alter anticoagulant effects, necessitating close monitoring of blood clotting parameters.

• NSAIDs (e.g., aspirin), which when used alongside triamcinolone, may increase the risk of gastrointestinal bleeding.

FOOD INTERACTIONS 

Food interactions with triamcinolone acetonide primarily affect oral forms of the medication, rather than topical creams or ointments. The most significant food-related concerns involve grapefruit and managing sodium and potassium intake.

CONTRAINDICATIONS

Triamcinolone is contraindicated in patients with tuberculosis, as it may increase the risk of disease reactivation. Additionally, individuals with diabetes mellitus should use caution with systemic triamcinolone, as it can cause elevated blood glucose levels—a common side effect of corticosteroids.

SIDE EFFECTS

• Dryness, flaking, crusting, burning, or blistering of the skin

• Irritation of the skin

• Soreness, itching, swelling, scaling, or pronounced redness

• Redness or scaling around the mouth

• Thinning or bruising of the skin, especially in areas like skin folds (e.g., between the fingers) or on the face (if applied there as directed)

OVER DOSE

An overdose of triamcinolone acetonide can lead to various medical issues, particularly with long-term use of high doses. The severity depends on the form of the drug, the dosage, and the duration of use. In case of a suspected overdose, get emergency medical help right away or contact a poison control center immediately.

TOXICITY 

Triamcinolone acetonide has known toxicities, particularly for the retina and bone cells, and systemic effects like Cushing syndrome, hypertension, and osteoporosis with chronic use or high doses. Triamcinolone acetonide is a potent synthetic corticosteroid that can cause various toxicities, depending on the route of administration, dosage, and duration of treatment. While it is generally considered safe when used as directed, systemic absorption and long-term use can lead to serious side effects.