The following CIOMS frequency rating is used, when applicable: Very common (≥10%); Common (≥1 and <10%); Uncommon (≥0.1 and <1%); Rare (≥0.01 and <0.1%); Very rare (<0.01%); Not known (cannot be estimated based on available data).
There is evidence of a dose-relationship for adverse effects associated with zolpidem use, particularly for certain CNS and gastrointestinal events. As recommended in Dosage & Administration, they should in theory be less if zolpidem is taken immediately before retiring, or in bed. They occur most frequently in elderly patients.
Immune system disorders:
Not known: angioneurotic oedema.
Common: hallucination, agitation, nightmare, depression (see Precautions).
Uncommon: confusional state, irritability, restlessness, aggression, somnambulism (see Precautions), euphoric mood.
Rare: libido disorder.
Very rare: delusion, dependence (withdrawal symptoms or rebound effects may occur after treatment discontinuation).
Not known: anger, psychosis, abnormal behaviour.
Most of these psychiatric undesirable effects are related to paradoxical reactions.
Nervous system disorders:
Common: somnolence, headache, dizziness, exacerbated insomnia, cognitive disorders such as anterograde amnesia (amnestic effects may be associated with inappropriate behaviour).
Uncommon: paraesthesia, tremor, disturbance in attention, speech disorder.
Rare: depressed level of consciousness.
Uncommon: diplopia, vision blurred.
Very rare: visual impairment.
Respiratory, thoracic and mediastinal disorders:
Very rare: respiratory depression (see Precautions).
Common: diarrhoea, nausea, vomiting, abdominal pain.
Uncommon: liver enzymes elevated.
Rare: hepatocellular, cholestatic or mixed liver injury (see Dosage & Administration, Contraindications and Precautions).
Metabolism and nutrition disorders:
Uncommon: appetite disorder.
Skin and subcutaneous tissue disorders:
Uncommon: rash, pruritus, hyperhidrosis.
Musculoskeletal and connective tissue disorders:
Common: back pain.
Uncommon: myalgia, muscle spasms, muscular weakness.
Infections and infestations:
Common: upper respiratory tract infection, lower respiratory tract infection.
General disorders and administration site conditions:
Rare: gait disturbance, fall (predominantly in elderly patients and when zolpidem was not taken in accordance with prescribing recommendation).
Not known: drug tolerance.
Reporting of suspected adverse reactions:
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions.