Systemic, local, and sclerotherapy drugs: What do we know about drug prescribing in vascular anomalies?

Off-label drug prescribing, frequent in the treatment of vascular anomalies (VA), relies on the quality of the literature reporting drug efficacy and safety. Our objective is to review the level of evidence (LOE) surrounding drug use in VA, which is more prevalent in pediatric care. A list of drugs used in VA was created with a literature review in July 2020. For each drug listed, the article displaying the highest LOE was determined and then compared between efficacy/safety data, routes of administration, pharmacological categories and a subset of VA. The influence of research quality on study results was also explored. The median LOE for the 74 drugs identified poor methodological quality, with a predominance of retrospective studies or case reports. Drug safety is currently inadequately reported. This is alarming as many treatments display significant safety concerns. Also, current literature displays major publication bias that probably leads to overestimation of drug efficacy in VA.

Off-Label Use and Safety of Drug Use in Vascular Anomalies.

BACKGROUND: Off-label drug use is associated with an increased risk of adverse drug reactions. It is common in pediatrics and in rare diseases, which are two characteristics applying to vascular anomalies (VA). OBJECTIVES: The aim of this work was to quantify off-label drug use in VA and assess its safety. METHODS: A review was conducted to extract a list of drugs used in VA management. A drug was considered to have significant safety concerns if a black box warning was present or if a serious adverse drug reaction (SADR) was reported in at least 1% of the patients (SADR is defined as a noxious and unintended response to a drug that occurs at any dose and results in hospitalization, prolongation of existing hospitalization, congenital malformation, persistent or significant disability or incapacity, life-threatening condition, or death). The labelling status and safety of each drug was assessed based on the product monograph, Micromedex, and the FDA data. RESULTS: We found that 98.9% of the inventoried drugs were used off-label or unlicensed for VA management. Only the oral solution of propranolol hydrochloride (Hemangeol®) for the treatment of infantile hemangiomas is approved. Significant safety issues concerned 73% of the drugs and were more frequent among systemic than locally delivered drugs. CONCLUSIONS: Off-label drug use in VA is the rule and not the exception. Significant safety concerns are common. It is necessary to carefully weigh risk and benefits for every patient when using systemic and local treatments carrying safety concerns. Patients should be openly informed and involved in the decision-making process.