Thalidomide is an immunomodulatory and anti-angiogenic agent, infamous for its teratogenic effects but now a critical therapy for specific severe conditions under strict control. It is a synthetic glutamic acid derivative with complex pharmacological actions, primarily used in India for the treatment of erythema nodosum leprosum (ENL) and multiple myeloma. Its use is governed by a highly restrictive distribution program (S.T.E.P.S. or equivalent) due to its severe teratogenic risk.
Adult: ENL: Initially 100-300 mg daily at bedtime, tapering by 50 mg every 2-4 weeks to a maintenance dose of 50-100 mg daily or every other day. Multiple Myeloma: 200 mg daily at bedtime, often in 28-day cycles with pulsed dexamethasone. Doses are often administered as 50mg capsules (e.g., 4 capsules for 200mg).
Note: Administer orally, preferably at bedtime to minimize daytime drowsiness and dizziness. Capsules should be swallowed whole with water. Can be taken with or without food, but taking with a high-fat meal may delay absorption. Do not break, chew, or open the capsule.
Thalidomide possesses a multifaceted mechanism involving immunomodulation, anti-angiogenesis, and anti-inflammatory effects. It inhibits tumor necrosis factor-alpha (TNF-α) production in monocytes by enhancing the degradation of TNF-α mRNA. It also co-stimulates T-cells, leading to increased production of interleukin-2 and interferon-gamma. Its anti-angiogenic effect is mediated by inhibition of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF).
Pregnancy: CATEGORY X. ABSOLUTELY CONTRANDICATED. Causes severe, life-threatening birth defects (limb abnormalities, internal organ malformations). Women of childbearing potential must have 2 negative pregnancy tests before starting, use 2 forms of contraception, and undergo monthly pregnancy tests.
Driving: NOT ADVISABLE. Causes drowsiness, dizziness, and somnolence. Patients must be warned not to drive or operate heavy machinery, especially when initiating therapy.
| Dexamethasone | Markedly increases risk of Venous Thromboembolism (VTE). Requires concurrent VTE prophylaxis (e.g., aspirin, LMWH). | High |
| Other Sedatives (Alcohol, Benzodiazepines, Opioids) | Additive CNS depression, increased risk of sedation, dizziness, and falls. | High |
| Drugs causing Bradycardia (Beta-blockers, Digoxin, Calcium Channel Blockers) | Additive effect on heart rate; risk of symptomatic bradycardia. | Moderate |
| Neurotoxic Agents (Bortezomib, Vincristine, Isoniazid) | Increased risk and severity of peripheral neuropathy. | High |
| Hormonal Contraceptives | Thalidomide may reduce efficacy. Women must use two highly effective methods of contraception (one barrier method). | High |