Assay interference Exercise Familial (mutant prolactin receptor) Idiopathic Macroprolactin (“big prolactin”) Nipple stimulation Neonatal Pregnancy Sleep (REM phase) Stress (trauma, surgery) Suckling | Amoxapine Amphetamines Anesthetic agents Antipsychotics (conventional and atypical) Androgens Butyrophenones Cimetidine (not famotidine or nizatidine) Cocaine use or withdrawal Domperidone Estrogens Hydroxyzine Licorice (real) Locaserin MAO inhibitors Methyldopa Metoclopramide Opioids Nicotine Phenothiazines Protease inhibitors Progestins Reserpine SSRIs Tricyclic antidepressants Verapamil | Acromegaly Chronic chest wall stimulation (thoracotomy, augmentation or reduction mammoplasty, mastectomy, herpes zoster, chest acupuncture, nipple rings, etc) Hypothalamic or pituitary stalk damage Hypothyroidism Liver disease Multiple sclerosis Optic neuromyelitis Prolactin-secreting tumors Pseudocyesis (false pregnancy) Kidney failure (especially with zinc deficiency) Spinal cord lesions Systemic lupus erythematosus |