Avastin: Update to last Blog
Update to last blog:
1. To doctors: I received an e-mail from a retinal surgeon who said that the pharmacies he uses keep Avastin® for only two weeks after it has been divided into smaller doses for intraocular use. Their concern is that it will become inactive. I checked with our pharmacy at The University of Iowa Hospitals and Clinics and they also keep the drug for only two weeks at 4◦ C. So the two-week limit on Avastin® is probably a good idea until we learn otherwise. To keep the price low, you may need to come up with a plan to bunch your patients so they can be injected within a two week period.
2. We received the following question (paraphrased) from a reader: “My mom was just diagnosed with wet AMD in one eye, and dry AMD in the other. She is scheduled to have her first Visudyne® treatment tomorrow but I was wondering if she should have Avastin® instead?”
Answer: Your mother’s eye doctor should be able to tell you if the new blood vessels are of the “classic” type and if they are, I think it is appropriate to try Visudyne®. Visudyne® is FDA approved and has been shown in clinical trials to be better than no treatment. Visudyne® also works best in eyes with classic neovascularization. I use intraocular Kenalog® with Visudyne® because I think the visual results are better but this is still unproven. Patients who have Visudyne® often have decreased vision for a week or so after treatment because of inflammation and increased fluid within and under the retina. If your mother has continued loss of vision after that, I would ask her ophthalmologist to re-evaluate her. If the neovascularization is enlarging, say after six weeks, or there still is a lot of fluid beneath the retina, I would ask him or her about intraocular Avastin®.
2. We received the following question from a reader: “Can you inform me if there are any studies indicating a connection [or lack of one] between Macular Degeneration and cardiac ‘blood thinners?’”
Answer: This is a good question. There is no evidence that aspirin, any other platelet inhibitor, or Coumadin® increases the progression of AMD. There is a lot of evidence however that Coumadin® increases the risk of severe bleeding in eyes of patients with the wet or neovascular form of AMD. The bleeding can be so severe that all vision is lost. Therefore, if you have the wet form of AMD, you should ask your doctor if you really need Coumadin®. Your doctor may or may not be able to take you off the drug, if for instance, you have an artificial heart valve, atrial fibrillation, or a history of strokes. If this is the case, then ask your doctor to keep the dose and the INR (a measure of how much you are anticoagulated) as low as possible.
One would think that aspirin or other platelet inhibitors would also increase the risk of bleeding in AMD but that hasn’t seemed to be the case.
References:
1. Rosenfeld PJ, Moshfeghi, AA, Puliafito CA. “Optical Coherence Tomography Findings after Intravitreal Injection of Bevacizumab (Avastin) for Neovascular Age-Related Macular Degeneration.” Opthalmic Surg Lasers Imag 2005;36:331-335.
2. Tilanus MA, et al. “Relationship between Anticoagulant Medication and Massive Intraocular Hemorrhage in Age-Related Macular Degeneration.” Graefes Arch Clin Exp Ophthalmol, 238:482-485, 2000.
3. Lewis H, Sloan, SH, Foos RY, “Massive Intraocular Hemorrhage Associated with Anticoagulation and Age-Related Macular Degeneration.” Graefes Arch Clin Exp Ophthalmol. 226:59-64, 1988.
4. el Baba F et al. “Massive Hemorrhage Complicating Age-Related Macular Degeneration. Clinicopathologic Correlation and Role of Anticoagulants.” Ophthalmology 93:1581-92, 1986.
1. To doctors: I received an e-mail from a retinal surgeon who said that the pharmacies he uses keep Avastin® for only two weeks after it has been divided into smaller doses for intraocular use. Their concern is that it will become inactive. I checked with our pharmacy at The University of Iowa Hospitals and Clinics and they also keep the drug for only two weeks at 4◦ C. So the two-week limit on Avastin® is probably a good idea until we learn otherwise. To keep the price low, you may need to come up with a plan to bunch your patients so they can be injected within a two week period.
2. We received the following question (paraphrased) from a reader: “My mom was just diagnosed with wet AMD in one eye, and dry AMD in the other. She is scheduled to have her first Visudyne® treatment tomorrow but I was wondering if she should have Avastin® instead?”
Answer: Your mother’s eye doctor should be able to tell you if the new blood vessels are of the “classic” type and if they are, I think it is appropriate to try Visudyne®. Visudyne® is FDA approved and has been shown in clinical trials to be better than no treatment. Visudyne® also works best in eyes with classic neovascularization. I use intraocular Kenalog® with Visudyne® because I think the visual results are better but this is still unproven. Patients who have Visudyne® often have decreased vision for a week or so after treatment because of inflammation and increased fluid within and under the retina. If your mother has continued loss of vision after that, I would ask her ophthalmologist to re-evaluate her. If the neovascularization is enlarging, say after six weeks, or there still is a lot of fluid beneath the retina, I would ask him or her about intraocular Avastin®.
2. We received the following question from a reader: “Can you inform me if there are any studies indicating a connection [or lack of one] between Macular Degeneration and cardiac ‘blood thinners?’”
Answer: This is a good question. There is no evidence that aspirin, any other platelet inhibitor, or Coumadin® increases the progression of AMD. There is a lot of evidence however that Coumadin® increases the risk of severe bleeding in eyes of patients with the wet or neovascular form of AMD. The bleeding can be so severe that all vision is lost. Therefore, if you have the wet form of AMD, you should ask your doctor if you really need Coumadin®. Your doctor may or may not be able to take you off the drug, if for instance, you have an artificial heart valve, atrial fibrillation, or a history of strokes. If this is the case, then ask your doctor to keep the dose and the INR (a measure of how much you are anticoagulated) as low as possible.
One would think that aspirin or other platelet inhibitors would also increase the risk of bleeding in AMD but that hasn’t seemed to be the case.
References:
1. Rosenfeld PJ, Moshfeghi, AA, Puliafito CA. “Optical Coherence Tomography Findings after Intravitreal Injection of Bevacizumab (Avastin) for Neovascular Age-Related Macular Degeneration.” Opthalmic Surg Lasers Imag 2005;36:331-335.
2. Tilanus MA, et al. “Relationship between Anticoagulant Medication and Massive Intraocular Hemorrhage in Age-Related Macular Degeneration.” Graefes Arch Clin Exp Ophthalmol, 238:482-485, 2000.
3. Lewis H, Sloan, SH, Foos RY, “Massive Intraocular Hemorrhage Associated with Anticoagulation and Age-Related Macular Degeneration.” Graefes Arch Clin Exp Ophthalmol. 226:59-64, 1988.
4. el Baba F et al. “Massive Hemorrhage Complicating Age-Related Macular Degeneration. Clinicopathologic Correlation and Role of Anticoagulants.” Ophthalmology 93:1581-92, 1986.
posted by James C. Folk, M.D. at 8:48 AM
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