TRIAMCINOLONE DIACETATE
Clinical safety rating: avoid
CYP3A4 inducers (eg phenytoin) may decrease efficacy and inhibitors may increase effects Can cause hyperglycemia and adrenal suppression with prolonged use.
Corticosteroid with anti-inflammatory and immunosuppressive properties; binds to glucocorticoid receptor, modulating gene expression and suppressing cytokine production, inflammation, and immune cell activity.
| Metabolism | Primarily hepatic via CYP3A4; undergoes reduction and conjugation; inactive metabolites excreted in urine and bile. |
| Excretion | Triamcinolone diacetate is metabolized primarily in the liver and excreted via the kidneys as inactive metabolites. Approximately 30-40% of an oral dose is excreted in urine as metabolites, with less than 5% as unchanged drug. Biliary/fecal excretion accounts for about 60-70% of the administered dose. |
| Half-life | The terminal elimination half-life is approximately 2-5 hours in adults. This relatively short half-life supports multiple daily dosing for chronic conditions, though the biological half-life (duration of adrenal suppression) is longer at 18-36 hours due to intracellular receptor binding. |
| Protein binding | Triamcinolone is approximately 68% bound to plasma proteins, primarily corticosteroid-binding globulin (CBG) and albumin. |
| Volume of Distribution | Volume of distribution is approximately 1.4 L/kg, indicating extensive tissue distribution and penetration into intracellular spaces. This reflects its lipophilic nature and ability to cross cell membranes. |
| Bioavailability | Oral: 20-25% due to first-pass metabolism in the liver. IM: 100% absolute bioavailability; intra-articular: locally high concentrations with negligible systemic absorption. |
| Onset of Action | Oral: 1-2 hours; intramuscular (IM) depot: 24-48 hours; intra-articular: 24-72 hours. Onset is delayed for sustained-release formulations. |
| Duration of Action | Oral: 12-36 hours; IM depot: 2-3 weeks; intra-articular: 4-6 weeks. Duration is prolonged due to slow release from esterified formulations and receptor-mediated effects. |
| Molecular Weight | 478.5 |
40 to 80 mg intramuscularly every 4 weeks; intra-articular: 5 to 40 mg per joint every 3-4 weeks; intralesional: up to 1 mg per injection site, not to exceed 0.1 mg per cm² of lesion.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dosage adjustment required for renal impairment; caution in severe impairment due to risk of fluid retention. |
| Liver impairment | No specific dosage adjustment guidelines; use with caution in severe hepatic impairment due to potential for increased systemic effects. |
| Pediatric use | Not recommended for children under 12 years; for adolescents, dosing based on adult recommendations with caution. |
| Geriatric use | Start at lower end of dosing range; monitor for increased adverse effects such as hyperglycemia, osteoporosis, and fluid retention. |
| 1st trimester | Associated with cleft palate in animal studies; use only if clearly needed. |
| 2nd trimester | May cause fetal adrenal suppression; monitor for intrauterine growth restriction. |
| 3rd trimester | Risk of neonatal adrenal suppression if used near term; avoid prolonged use. |
Clinical note
CYP3A4 inducers (eg phenytoin) may decrease efficacy and inhibitors may increase effects Can cause hyperglycemia and adrenal suppression with prolonged use.
| FDA category | Positive |
| Placental transfer | Placental transfer occurs; metabolized to active form. |
| Breastfeeding | Enters breast milk in low amounts; monitor infant for adrenal suppression and growth delay. |
■ FDA Black Box Warning
None.
| Common Effects | Hyperglycemia |
| Serious Effects |
Systemic fungal infectionHypersensitivity to triamcinolone or any componentIntrathecal administration
| Precautions | Immunosuppression increased infection risk; adrenal suppression with prolonged use; Cushing's syndrome; osteoporosis; avascular necrosis; exacerbation of fungal, bacterial, viral infections; avoid live vaccines; monitoring for HPA axis suppression; potential for growth retardation in children; use with caution in diabetes, hypertension, congestive heart failure, peptic ulcer disease, ulcerative colitis, diverticulitis, renal insufficiency, hypothyroidism, cirrhosis, ocular herpes simplex. |
| Food/Dietary | No specific food interactions. However, corticosteroids may cause fluid retention; consider reducing sodium intake to minimize edema. Concomitant use with grapefruit juice may increase triamcinolone levels; avoid concurrent consumption. |
Loading safety data…
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Increased risk of cleft palate (odds ratio 3.4) and neural tube defects. Second trimester: Risk of intrauterine growth restriction and premature rupture of membranes with systemic use. Third trimester: Risk of neonatal adrenal suppression, hypoglycemia, and transient growth retardation. Corticosteroids are classified as FDA Category C; avoid systemic use in first trimester unless life-threatening. |
| Fetal Monitoring | Monitor maternal blood pressure, blood glucose (risk of hyperglycemia), and signs of infection. Serial fetal growth ultrasounds (every 4-6 weeks) for intrauterine growth restriction. Assess fetal well-being with nonstress testing or biophysical profile if high-dose therapy. Monitor neonatal adrenal function after delivery (serum cortisol, ACTH stimulation test). |
| Fertility Effects | May disrupt ovarian function and menstrual regularity via hypothalamic-pituitary-adrenal suppression. Reversible impaired fertility in both sexes (reduced sperm count and motility). Use for chronic conditions may delay time to conception; avoid if actively trying to conceive unless necessary. |
| Clinical Pearls | Triamcinolone diacetate (Aristospan, Keralog) is a long-acting, water-soluble corticosteroid ester with greater potency than triamcinolone acetonide. For intralesional use, inject into the dermis, not subcutaneously, to avoid fat atrophy. Post-injection flare is less common than with acetonide. Due to its solubility, systemic absorption is more rapid when injected intra-articularly or into soft tissue; limit repeat injections to every 4-6 weeks. In epidural steroid injections, triamcinolone diacetate may be associated with lower risk of adhesive arachnoiditis compared to particulate steroids. Monitor for adrenal suppression with prolonged use or high doses. Do not use in patients with systemic fungal infections or idiopathic thrombocytopenic purpura. |
| Patient Advice | Do not stop taking this medication abruptly; the dose must be gradually reduced under medical supervision. · Avoid live vaccines (e.g., MMR, nasal flu) during treatment. · Report any signs of infection (fever, sore throat), unusual bruising/bleeding, vision changes, or weight gain. · This medication may raise blood sugar; monitor closely if diabetic. · Use caution with NSAIDs (ibuprofen, naproxen) to avoid increased GI bleeding risk. · Avoid exposure to chickenpox or measles; inform your doctor if you have been exposed. · Do not receive the flu shot or other live virus vaccines while on this medication. |