A 4.25 or 5% solution of amino acids (without additives) is slightly hypertonic. A 3.5% concentration of amino acids (without additives) is slightly hypertonic. Local reactions consisting of a warm sensation, erythema, phlebitis and thrombosis at the infusion site have occurred with peripheral intravenous infusion of amino acids particularly if other substances, such as antibiotics, are also administered through the same site. In such cases the infusion site should be changed promptly to another vein. Use of large peripheral veins, inline filters, and slowing the rate of infusion may reduce the incidence of local venous irritation. Electrolyte additives should be spread throughout the day. Irritating additive medications may need to be injected at another venous site.
Generalized flushing, fever and nausea also have been reported during peripheral infusions of amino acid solutions.