The lives of hundreds of patients awaiting life-saving surgical or interventional procedures at the Sri Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) here have been put in peril by the nationwide non-availability or blanket ban on a specific drug, a liquid embolising agent called Onyx 18.

Onyx 18 is a single drug crucial for the treatment of arteriovenous malformations (AVMs), mostly in the brain (can be used for vascular malformations in the body too) and widely used by interventional radiologists.

But non-availability of this drug for the past one year or more, following a ban/regulation imposed by the Drugs Controller General of India, has hundreds of brain AVM patients facing the risk of massive bleeding and death, even as they wait for surgery.

“We can use substitute drugs in the case of vascular malformations in other parts of the body. But the safety window for the brain is narrow and we have found Onyx 18 to be extremely safe for brain AVMs. At present, we have over 70 AVM patients in deteriorating stages, in the productive age group, who cannot be treated because Onyx 18 is not available,” says E. R. Jayadevan, Assistant Professor, Interventional Radiology, SCTIMST. An AVM is an abnormal tangle of veins and arteries, resulting in the blood flowing directly from the arteries to the veins, bypassing smaller vessels called capillaries. The high pressure of this direct flow causes veins to widen and the patient risks extreme bleeds.

AVMs can be safely removed through surgery. But prior to surgery, in order to prevent huge blood loss and damage to brain tissue, the blood flow in the vessel has to be blocked or reduced through embolisation.

The embolising agent is injected into a fine catheter inserted through the leg artery to the AVM site by the interventional radiologist. This drug acts like an adhesive and hardens when it comes into contact with blood, helping block/reduce blood flow to AVM, after which the surgeon can resect the AVM.

“We have been writing to the Centre as well as the DCGI about the gravity of the situation and the urgent need to import Onyx, but to no avail. We are now told that the regulation has been lifted but that several technical issues are preventing the import. Some patients, by appealing to the DCGI about life-threatening condition, have managed to import the drug in dollars rates for their own use,” a senior SCTIMST official said.