 The effect will not be instant, but the dangerous and unpleasant massive histamine release from the intravenous injection of codeine is avoided.To minimize the amount of undissolved material in fluids prepared for injection, a filter of cotton or synthetic fiber is typically used, such as a cotton-swab tip or a small piece of cigarette filter.Some manufacturers add the narcotic antagonist naloxone or the anticholinergics atropine and homatropine (in lower than therapeutic doses) to their pills to prevent injection.