Loperamide: The most frequently reported undesirable effects with loperamide include nausea, constipation, headache, abdominal cramps, dizziness, dry mouth, dysgeusia (altered taste), vomiting, flatulence, dyspepsia, drowsiness, fatigue, urinary retention, difficulty urinating, abdominal pain, distension, or discomfort.
Immune system disorders: Anaphylactic shock (serious allergic reaction which causes difficulty in breathing or dizziness), angioedema (rapid swelling of the skin).
Nervous system disorders: Coordination abnormality, loss/depressed level of consciousness, stupor (decreased mental alertness).
Eye disorders: Miosis (constriction of the pupil of the eye).
Cardiac disorders: Cardiac arrest (stopping of heartbeat), QT interval prolongation, syncope (fainting/temporary loss of consciousness), torsades de pointes/ventricular arrhythmias (life-threatening irregular heartbeat).
Respiratory, thoracic and mediastinal disorders: Respiratory depression (slow, shallow or ineffective breathing), shortness of breath, unexplained wheezing.
Gastrointestinal disorders: Glossodynia (burning sensation or pain around the tongue), paralytic ileus (obstruction of the intestine due to paralysis of the intestinal muscles), toxic megacolon (acute dilatation of the colon associated with infection or inflammation).
Skin and subcutaneous tissue disorders: Erythema multiforme (a skin condition characterized by symmetrical, red, raised skin areas all over the body), pruritus (itching), rash, serious skin reactions (i.e., Stevens-Johnson syndrome and toxic epidermal necrolysis) which may include symptoms such as reddening of the skin, rash, blisters, and detachment of the upper surface of the skin; urticaria (itchy rash).
Musculoskeletal and connective tissue disorders: Hypertonia (muscle stiffness).
Simeticone: There have been no reports of undesirable effects after ingestion of simeticone. A very severe allergic reaction is rare. However, if the patient notices any undesirable effects, consult a doctor immediately.