Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities
Net loss	$ (41,947)	$ (34,065)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	932	965
Change in right-of-use assets	246	0
Amortization of financing costs	19	15
Noncash interest expense	1,871	3,071
Share-based compensation expense	2,581	3,060
Obsolete inventory reserve	582	0
Change in fair value of derivative liabilities	0	3
Loss on extinguishment of debt	50	0
Impairment of assets	0	20
Sales return provision	61	(214)
Changes in:
Accounts receivable	(126)	(1,609)
Inventories	(2,420)	1,398
Prepaid expense and other current assets	(162)	(503)
Other assets	(148)	(170)
Accounts payable	217	(2,487)
Accrued expense	4,116	2,211
Operating lease liabilities	(202)	0
Deferred rent liability	0	51
Net cash used in operating activities	(34,330)	(28,254)
Investing activities
Acquisition of property and equipment	(1,409)	(1,166)
Net cash used in investing activities	(1,409)	(1,166)
Financing activities
Repayment of finance lease	(90)	(51)
Proceeds from issuance of common stock and exercise of warrants, net of fees	11,239	27,549
Proceeds from issuance of common stock through ESPP	0	236
Net cash provided by financing activities	11,149	27,734
Net decrease in cash and cash equivalents	(24,590)	(1,686)
Cash and cash equivalents-beginning of period	47,758	25,961
Cash and cash equivalents-end of period	23,168	24,275
Supplemental disclosures of cash flow information
Right-of-use assets	2,592	0
Operating lease liability	2,700	0
Deferred rent	109
Cash interest payment on long-term debt	1,542	0
Exchange of debt to Series B Preferred Stock	25,000	0
Commitment fee for Second Purchase Agreement	0	429
Deferred revenue reduction	0	1,638
Sales return reserve	0	778
Deferred cost of goods sold reduction	0	539
Accrued distribution fees and managed care costs	0	343
Noncash investing and financing
Capital lease obligation	0	315
Accrued/payable offering costs	103	84
Accrued/payable debt exchange costs	115	0
Property and equipment additions included in accounts payable	$ 93	$ 0