When any of those slips, the result is usually minor and short-lived, but it is worth understanding what can actually go wrong, and why we think this is a job for a clinician rather than a kitchen-table DIY
Must be administered by a healthcare professional.
(These effects are really due to contamination, not the water itself.) Allergic/hypersensitivity reactions: True allergy to benzyl alcohol is uncommon, but possible

Neurological: convulsions, increased intracranial pressure with papilledema (pseudotumor cerebri) usually after treatment, vertigo, headache Endocrine: menstrual irregularities, development of cushingoid state, suppression of fetal intrauterine or childhood growth, lack of secondary response of the adrenal cortex or pituitary gland, particularly in situations of stress such as trauma, surgery or illness, decreased carbohydrate tolerance, manifestations of latent diabetes mellitus, increased requirements of insulin or oral hypoglycemic agents in diabetic patients Ophtalmic: posterior subcapsular cataracts, increased intraocular pressure, glaucoma, exophthalmos Metabolic: negative nitrogen balance due to protein catabolism Psychiatric: euphoria, mood swings, severe depression to frank psychotic manifestations, personality changes, hyperirritability, insomnia Others: anaphylactoid or hypertensive reactions and hypotension or shock-like reaction Cyanocobalamin and hydroxocobalamin: hypervitaminosis and side effects were not observed with their use Dosage and administration Adults Coated tablets: 1 coated tablet 2 times a day
