| Undesirable effects are classified according to organ system and frequency. The frequency range is defined as very common ( 1/10), common ( 1/100, <1/10), uncommon ( 1/1000, <1/100), rare ( 1/10,000, <1/1000) and very rare (<1/10,000) not known (cannot be estimated from the available data).Very common, common and uncommon undesirable effects have been obtained from clinical trials. Very rare undesirable effects have been obtained from spontaneous post-marketing reports.Organ system | Undesirable effects | Frequency | Immune system disorders | Hypersensitivity reactions incl. angioedema, urticaria, bronchospasm, hypotension, collapse | Very rare | Metabolism and nutrition disorders | Hypokalaemia | Rare | Nervous system disorders | Tremor, headache. Hyperactivity, sleep disturbances, hyperexcitability, hallucinations | Common Very rare | Cardiac disorders | Tachycardia Palpitations Cardiac arrhythmia (e.g. atrial fibrillation, supraventricular tachycardia and extrasystoles), myocardial ischaemia | Common Uncommon Very rare | Vascular disorders | Peripheral vasodilatation | Rare | Respiratory, thoracic and mediastinal disorders | Paradoxical bronchospasm | Very rare | Gastrointestinal disorders | Irritation in mouth and throat | Uncommon | Musculoskeletal and connective tissue disorders | Muscle cramps | Common | Undesirable effects typical of beta2-agonists, such as skeletal muscle tremor and palpitations, can occur especially at the beginning of treatment, and are often dose-dependent.As with other inhalation therapy, paradoxical bronchospasm may occur with an immediate increase in wheezing after dosing. This should be treated immediately with an alternative presentation or a different fast-acting inhaled bronchodilator. Salbutamol should be discontinued immediately, the patient assessed, and, if necessary, alternative therapy instituted | |