Pune : The joint national task force for Covid-19 has said posaconazole injections can be used to treat mucormycosis, also known as black fungus, if amphotericin B is unavailable or cannot be used in patients with severe intolerance to the drug. With a nationwide shortage of the drug for over two months now, experts said the advisory on posaconazole use is primarily a stopgap until supply improves.
The drug inhibits the synthesis of ‘ergosterol’, which is an important component of the fungal cell wall, to prevent fungal growth. “It (injectable posaconazole) is usually recommended as an alternative when both the liposomal or conventional amphotericin B formulations are unavailable. It can also be used if a patient cannot tolerate amphotericin B,” infectious diseases expert Dr Sanjay Pujari, a task force member said.
As many as 28,252 mucormycosis cases have been reported from 28 states and UTs. Most are from Maharashtra (6,339) and Gujarat (5,486), the health ministry had said last week. In India, posaconazole is available both as an oral tablet and intravenous (IV) injection. “The maximum posaconazole concentration in the blood with IV formulation is seven-fold higher compared to that achieved by a single tablet. This is important during primary treatment of mucormycosis to achieve rapid anti-fungal effect,” Pujari said. However, he added the injectable form is recommended only as initial therapy if availability of amphotericin B is a problem. “Oral tablets of posaconazole are preferred as step-down treatment and continued for three to six months to prevent a recurrence.”
Posaconazole is available from international and Indian manufacturers. Its availability early on was limited, but experts involved in the drug’s distribution said scaled up manufacturing will increase stock.
“Posaconazole generally benefits patients who do not have aggressive disease,” said Ruby Hall Clinic’s ENT surgeon Dr Sandeep Karmarkar.
Dr Samir Joshi, ENT surgeon with Sassoon Hospital, said, “Amphotericin B is the key anti-mucormycosis drug. Posaconazole is certainly effective. Its inclusion in the advisory looks more like a stopgap arrangement to foster confidence and address the issue of shortage.”