Ranibizumab is a recombinant humanized monoclonal antibody fragment (Fab) designed for intraocular use. It binds to and inhibits the biological activity of all active forms of human vascular endothelial growth factor A (VEGF-A), a key mediator of angiogenesis and vascular permeability. In the Indian context, it is a critical therapeutic agent for managing neovascular (wet) age-related macular degeneration (AMD), diabetic macular edema (DME), and other retinal vascular disorders, offering a targeted approach to prevent vision loss.
Adult: 0.5 mg (0.05 mL of the 10 mg/mL solution) administered by intravitreal injection once a month. For wet AMD, after the first 3 monthly injections, treatment interval may be individualized (e.g., treat-and-extend or pro re nata (PRN) based on disease activity as assessed by OCT and visual acuity). For DME and RVO, monthly dosing is typically initiated, with potential for individualization after initial period.
Note: FOR INTRAVITREAL USE ONLY. Administer under strict aseptic conditions, including use of sterile gloves, drape, and eyelid speculum. Adequate anesthesia (topical or subconjunctival) and a broad-spectrum topical antimicrobial agent are required pre-injection. The injection is given 3.5-4.0 mm posterior to the limbus (in phakic patients) into the vitreous cavity. Monitor intraocular pressure (IOP) and perfusion of the optic nerve head post-injection. Patient must be monitored for signs of endophthalmitis.
Ranibizumab is a 48 kDa antigen-binding fragment (Fab) derived from the same parent mouse antibody as bevacizumab. It is affinity-matured to provide stronger binding to VEGF-A. By binding with high affinity to all biologically active isoforms of VEGF-A (e.g., VEGF110, VEGF121, VEGF165), it prevents VEGF-A from interacting with its receptors (VEGFR-1 and VEGFR-2) on the surface of endothelial cells. This inhibition blocks key downstream signaling pathways that lead to endothelial cell proliferation, angiogenesis (new blood vessel formation), and vascular hyperpermeability (leakage).
Pregnancy: Category C. Animal reproduction studies have shown adverse effects. There are no adequate and well-controlled studies in pregnant women. VEGF inhibition is implicated in fetal development. Use only if the potential benefit justifies the potential risk to the fetus. For a sight-threatening condition, treatment may be considered after detailed counselling.
Driving: May cause temporary blurred vision, floaters, or light sensitivity after injection. Patients should not drive or operate machinery until their vision has stabilized, usually by the next day.
| Other Anti-VEGF Agents (e.g., Aflibercept, Bevacizumab) | Theoretical increased risk of ocular or systemic adverse effects. Concomitant use in the same eye is not recommended. | Major |
| Anticoagulants/Antiplatelets (e.g., Warfarin, Clopidogrel, Aspirin) | May increase risk of conjunctival or intraocular hemorrhage during injection. However, these medications should NOT be discontinued routinely as the risk of thromboembolic events outweighs the bleeding risk. Inform the ophthalmologist. | Moderate |
| Topical Ocular Steroids (e.g., Prednisolone acetate) | May be used concomitantly to manage post-injection inflammation. No known pharmacokinetic interaction. | Minor |