Due to the risk of urinary retention, only patients who are willing and/or able to initiate catheterization post-treatment, if required, should be considered for treatment.In patients who are not catheterizing, post-void residual (PVR) urine volume should be assessed within 2 weeks post-treatment and periodically as medically appropriate up to 12 weeks. Catheterization should be instituted if PVR urine volume exceeds 200 mL and continued until PVR falls below 200 mL. Patients should be instructed to contact their physician if they experience difficulty in voiding as catheterization may be required. Human albumin and spread of viral diseases. BOTOX ® and BOTOX ® Cosmetic contains albumin, a protein component of human blood. The potential risk of spreading viral diseases (e.g., Creutzfeldt-Jakob disease [CJD]) via human serum albumin is extremely rare. No cases of viral diseases or CJD have ever been reported in association with human serum albumin. Tell your doctor about all your medical conditions, including if you: have or have had bleeding problems; have plans to have surgery; had surgery on your face; weakness of forehead muscles, such as trouble raising your eyebrows; drooping eyelids; any other abnormal facial change; have symptoms of a urinary tract infection (UTI) and are being treated for urinary incontinence. Symptoms of a urinary tract infection may include pain or burning with urination, frequent urination, or fever; have problems emptying your bladder on your own and are being treated for urinary incontinence; are pregnant or plan to become pregnant (it is not known if BOTOX ® or BOTOX ® Cosmetic can harm your unborn baby); are breastfeeding or plan to breastfeed (it is not known if BOTOX ® or BOTOX ® Cosmetic passes into breast milk). Tell your doctor about all the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal products. Using BOTOX ® or BOTOX ® Cosmetic with certain other medicines may cause serious side effects. Do not start any new medicines until you have told your doctor that you have received BOTOX ® or BOTOX ® Cosmetic in the past. Especially tell your doctor if you: have received any other botulinum toxin product in the last 4 months; have received injections of botulinum toxin such as Myobloc ®, Dysport ®, or Xeomin ® in the past (be sure your doctor knows exactly which product you received); have recently received an antibiotic by injection; take muscle relaxants; take an allergy or cold medicine; take a sleep medicine; take anti-platelets (aspirin-like products) or anti-coagulants (blood thinners). Other side effects of BOTOX ® and BOTOX ® Cosmetic include: dry mouth, discomfort or pain at the injection site, tiredness, headache, neck pain, and eye problems: double vision, blurred vision, decreased eyesight, drooping eyelids, swelling of your eyelids, and dry eyes; urinary tract infection and/or inability to empty your bladder on your own (in people being treated for urinary incontinence). For more information refer to the Medication Guide or talk with your doctor.