<p>Do not administer rabies immunoglobulin intravenously (due to the risk of shock i.e., sudden collapse with drop in blood pressure). Consequently, make sure that the needle has not penetrated a blood vessel. Rabies immunoglobulin should not be administered in repeated doses. Once the vaccine treatment has been started, repeating injections of rabies immunoglobulin may reduce the protective efficacy that must be guaranteed by the vaccine. Shake well before use. Do not shake vigorously.</p>