The most commonly reported adverse reactions are nausea and dizziness, both occurring in >10% of patients.
The frequencies are defined as follows: Very common ≥1/10; Common ≥1/100, <1/10; Uncommon ≥1/1000, <1/100; Rare ≥1/10,000, <1/1000; Very rare <1/10,000. Not Known: Cannot be estimated from the available data.
Uncommon: cardiovascular regulation (palpitation, tachycardia). These adverse reactions may occur especially on intravenous administration and in patients who are physically stressed. Rare: bradycardia, increased in blood pressure.
Rare: increase in blood pressure.
Uncommon: cardiovascular regulation (postural hypotension or cardiovascular collapse). These adverse reactions may occur especially on intravenous administration and in patients who are physically stressed.
Metabolism and nutrition disorders:
Rare: changes in appetite.
Respiratory, thoracic and mediastinal disorders:
Rare: respiratory depression, dyspnea.
If the recommended doses are considerably exceeded and other centrally depressant substances are administered concomitantly (refer to Interactions), respiratory depression may occur. Worsening of asthma has been reported, though a causal relationship has not been established.
Nervous system disorders:
Very common: dizziness. Common: headache, somnolence. Rare: speech disorders, paraesthesia, tremor, epileptiform convulsions, muscle contractions involuntary, coordination abnormal, syncope.
Convulsions occurred mainly after administration of high doses of Tramadol or after concomitant treatment with medicinal products which can lower the seizure threshold. (Refer to Precautions and Interactions).
Rare: hallucination, confusional state, sleep disturbance, delirium, anxiety and nightmares. Psychic adverse reactions may occur following administration of tramadol which vary individually in intensity and nature (depending on personality and duration of treatment). These include changes in mood (usually euphoric mood, occasionally dysphoria), changes in activity (usually suppression, occasionally increase) and changes in cognitive and sensorial capacity (e.g. decision behavior, perception disorders). Drug dependence may occur. Symptoms of drug withdrawal syndrome, similar to those occurring during opiate withdrawal, may occur as follows: agitation, anxiety, nervousness, insomnia, hyperkinesia, tremor and gastrointestinal symptoms. Other symptoms that have very rarely been seen with tramadol discontinuation include: panic attacks, severe anxiety, hallucinations, paraesthesias, tinnitus and unusual CNS symptoms (i.e. confusion, delusions, depersonalization, derealization, paranoia).
Rare: miosis, mydriasis, blurred vision.
Very common: nausea. Common: constipation, dry mouth, vomiting. Uncommon: retching, gastrointestinal discomfort (a feeling of pressure in the stomach, bloating), diarrhea.
Skin and subcutaneous tissue disorders:
Common: hyperhidrosis. Uncommon: dermal reactions (e.g. pruritus, rash, urticaria).
Rare: motor weakness.
In a few isolated cases hepatic enzyme increases have been reported in a temporal connection with the therapeutic use of tramadol.
Renal and urinary disorders:
Rare: micturition disorders (dysuria and urinary retention).
Immune system disorders:
Rare: allergic reactions (e.g. dyspnea, bronchospasm, wheezing, angioneurotic edema) and anaphylaxis.