Avenue Therapeutics gets letter from USFDA for intravenous tramadol Kumar Jeetendra | October 12, 2020 Therapeutics Inc has received a complete response letter (CRL) in the US health regulator for its new drug application for intravenous tramadol. The CRL in the US Food and Drug Administration (USFDA) has said that the regulator has decided it cannot approve the application for IV tramadol in its current form, Avenue Therapeutics said in …