Pharmacokinetics and pharmacodynamics of lignocaine: A review

Table 2 Adverse effects of lignocaine toxicity

System	Effects
CNS	Biphasic effects
	Early: CNS excitation with seizures
	Late: CNS depression, termination of convulsions, reduced level of consciousness, leading to respiratory depression and/or arrest
	Mechanism: Local inhibition of inhibitory CNS pathways (CNS stimulation), then inhibition of inhibitory and excitatory pathways (CNS inhibition)
	Symptoms and signs
	Anxiety
	Dizziness or light headed
	Confusion
	Euphoria
	Tinnitus
	Blurring of vision or diplopia
	Nausea and vomiting
	Twitching and tremors
	Seizures with reduced consciousness
Cardiovascular	General effects
	Conduction block of neural impulses
	Prevention of passage of sodium through sodium channels
	Stabilization of excitable membranes
	Prevention of the initiation and transmission of nerve impulses
	Attenuation of phase 4 diastolic depolarization
	Reduction in automaticity
	Reduction in absolute refractory period
	Increase in the ratio of effective refractory period: action potential duration
	Decrease in action potential duration
	Ventricular fibrillation threshold: raised
	Higher serum concentrations
	Blockage of sodium channels
	Depression of rate of depolarization during phase 0 of the cardiac action potential
	Re-entrant arrhythmias
	Suppression of conduction through the sinus and atrioventricular nodes
	Symptoms and signs
	Bradycardia
	Hypotension
	Cardiovascular depression
	Cardiac arrest
Respiratory	Symptoms and signs
	Tachypnea
	Respiratory depression
	Respiratory arrest
Allergic reactions	Extremely rare
	Symptoms and signs
	Cutaneous lesions: urticaria, edema
	Anaphylaxis

CNS: Central nervous system.