Dantrolene Oral Pill

See also Warning section. Drowsiness, dizziness, weakness, tiredness, nausea, and diarrhea may occur as your body adjusts to this medication and usually lessen after several days. Headache, constipation, trouble speaking, and drooling may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: vision changes, black/tarry stools, vomit that looks like coffee grounds, mental/mood changes, trouble swallowing, problems with urination, severe/persistent constipation, seizures, fast heartbeat, easy bruising/bleeding, signs of infection (such as fever, chills, persistent sore throat), chest pain, swelling of the ankles/feet, trouble breathing. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.