Like all medicines, this medicine can cause side effects, although not everybody gets them.
Very common (may affect more than 1 in 10 people): nausea, vomiting, dizziness, drowsiness, headache.
Common (may affect up to 1 in 10 people): decreased appetite, anxiety, confusion, hallucination, sleep problem, abnormal dreams, trembling, flushing, constipation, diarrhoea, indigestion, dry mouth, itching, increased sweating, rash, muscle cramps, feeling of weakness, fatigue, feeling of body temperature change.
Uncommon (may affect up to 1 in 100 people): depressed mood, disorientation, excitability (agitation), nervousness, restlessness, euphoric mood, drug dependence, disturbance in attention, memory impairment, near fainting, sedation, difficulty in controlling movements, difficulty in speaking, numbness, abnormal sensations of the skin (e.g. tingling, prickling), muscle twitches, abnormal vision, faster heartbeat, palpitations, decreased blood pressure, dangerously slow or shallow breathing (respiratory depression), less oxygen in the blood, shortness of breath, abdominal discomfort, hives, sensation of heaviness, delay in passing urine, frequent urination, drug withdrawal syndrome (see “If you stop taking PALEXIA”), accumulation of water in the tissue (oedema), feeling abnormal, feeling drunk, irritability, feeling of relaxation.
Rare (may affect up to 1 in 1,000 people): allergic reaction to medicines (including swelling beneath the skin, hives, and in severe cases difficulty breathing, a fall in blood pressure, collapse, or shock), thinking abnormal, epileptic fit, depressed level of consciousness, coordination abnormal, slower heartbeat, impaired gastric emptying.
Not known (frequency cannot be estimated from the available data): Delirium
In general, the likelihood of having suicidal thoughts and behaviour is increased in patients suffering from chronic pain. In addition, certain medicines for the treatment of depression (which have an impact on the neurotransmitter system in the brain) may increase this risk, especially at the beginning of treatment. Although tapentadol also affects neurotransmitters, data from human use of tapentadol do not provide evidence for an increased risk.