To avoid an upset stomach it is recommended to take Flexabenz ER Capsule with food It is generally advised to use the smallest effective dose for the shortest duration necessary to control symptoms Regular use of this medication is important while it is needed and it is important not to miss any doses to ensure effectiveness Common side effects of this medication may include sleepiness dry mouth fatigue and headache If any of these side effects persist or worsen it is important to inform your doctor Your doctor may be able to suggest strategies to prevent or minimize these symptoms Before taking this medication ensure its safety by informing your doctor about any medical conditions or disorders you may have It is also important to disclose all other medications you are currently using or taking Pregnant and breastfeeding women should consult with their doctors before using this medication