Lidocaine

Intravenous
Pulseless ventricular fibrillation or ventricular tachycardia
Adult: 1-1.5 mg/kg repeated as necessary. Max: 3 mg/kg. For ventricular arrhythmias in more stable patients: Usual loading dose: 50-100 mg as an IV inj at 25-50 mg/min, may repeat once or twice up to a max of 200-300 mg in 1 hr, followed by 1-4 mg/min via continuous IV infusion. May need to reduce dose if the infusion is longer than 24 hr.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Parenteral
Sympathetic nerve block
Adult: As 1% soln: 50 mg for cervical block or 50-100 mg for lumbar block.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Epidural
Epidural anaesthesia
Adult: 2-3 mL administered for each dermatome to be anaesthesised. Recommended doses are: Lumbar epidural 250-300 mg (as 1% soln) for analgesia and 225-300 mg (as 1.5% soln) or 200-300 mg (as 2% soln) for anaesth; for thoracic epidural: 200-300 mg (as 1% soln). For obstetric caudal analgesia: 200-300 mg (as 1% soln); for surgical caudal anaesth: 225-300 mg (as 1.5% soln). For continuous epidural or caudal anaesth, not to repeat max doses more frequently than 1.5 hrly.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Intraspinal
Spinal anaesthesia
Adult: As hyperbaric soln of 1.5% or 5% lidocaine in 7.5% glucose soln. Normal vaginal delivery: Up to 50 mg (as 5% soln) or 9-15 mg (as 1.5% soln). Caesarian operation: Up to 75 mg (as 5% soln). Other surgical procedures: 75-100 mg.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Intravenous
As an intravenous regional anaesthesia
Adult: As 0.5% soln w/o epinephrine: 50-300 mg. Max: 4 mg/kg.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Urethral
Surface anaesthesia
Adult: As 2% gel: Female: 60-100 mg inserted into the urethra several min before examination. Male: 100-200 mg before catheterisation and 600 mg before sounding or cystoscopy.

Intramuscular
Emergency treatment of ventricular arrhythmias
Adult: 300 mg injected into the deltoid muscle, repeat after 60-90 min if necessary.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Parenteral
Percutaneous infiltration anaesthesia
Adult: As 0.5% or 1% soln: 5-300 mg.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Parenteral
Peripheral nerve block
Adult: As 1.5% soln: For brachial plexus block: 225-300 mg. As 2% soln: For dental nerve block: 20-100 mg. As 1% soln: For intercostal nerve block: 30 mg; for paracervical block: 100 mg on each side, repeated not more frequently than every 90 min; for paravertebral block: 30-50 mg; for pudendal block: 100 mg on each side. As 4% soln: For retrobulbar block: 120-200 mg.
Hepatic impairment: Dosage reduction may be needed.
Incompatibility: Amphotericin B, sulfadiazine Na, methohexital Na, cefazolin Na, phenytoin Na, pantoprazole, metoprolol.

Transdermal
Postherpetic neuralgia
Adult: As 5% patch: Apply to most painful area once daily for up to 12 hr w/in a 24-hr period. Max: Up to 3 patches in a single application.

Mouth/Throat
Surface anaesthesia
Adult: As 2% soln: For pain: 300 mg rinsed and ejected for mouth and throat pain; or gargled and swallowed if necessary for pharyngeal pain. Not to be used more frequently than every 3 hr. Max (topical oral soln): 2.4 g/day. As 4% soln: Before bronchoscopy, bronchography, laryngoscopy, oesophagoscopy, endotracheal intubation, and biopsy in the mouth and throat: 40-200 mg. As 10% soln: For dentistry and otorhinolaryngology procedures: 10-50 mg sprayed to mucous membrane. As 4% soln: For laryngotracheal anaesth: 160 mg sprayed or instilled as a single dose into the lumen of the larynx and trachea.

Ophthalmic
Surface anaesthesia
Adult: Apply 2 drops to ocular area where procedure will take place; may reapply to maintain effect.

Topical/Cutaneous
Surface anaesthesia
Adult: As 5% oint: Max: 20 g in 24 hr for skin and mucous membrane. As 2% gel: Approx 120-220 mg into urethra several min before examination. As 4% foam: Apply 3-4 times daily for pain relief. As soln: Apply 40-200 mg to affected area. As patch: Apply patch to painful area for up to 12 hr w/in a 24-hr period. Max: 1 patch/24 hr.

Rectal
Haemorrhoids
Adult: Apply topically or using applicator insert rectally, up to 6 times daily.
Child: ≥12 yr Apply topically or using applicator insert rectally, up to 6 times daily.

Rectal
Perianal pain and itching
Adult: Apply topically or using applicator insert rectally, up to 6 times daily.
Child: ≥12 yr Apply topically or using applicator insert rectally, up to 6 times daily.

Hypovolaemia, complete heart block, Adam-Stokes syndrome, Wolff-Parkinson-White syndrome. Must not be applied to inflamed or injured skin.

Patient w/ pseudocholinesterase deficiency, cardiac conduction disturbances, resp depression. Hepatic and renal impairment. Elderly or debilitated patients. Pregnancy and lactation. Patient Counselling May cause temporary loss of sensation and motor activity. Monitoring Parameters Monitor CV and resp vital signs, LFTs and careful ECG observation.

Arrhythmia, bradycardia, arterial spasms, CV collapse, oedema, flushing, heart block, hypotension, sinus node suppression, agitation, anxiety, coma, confusion, drowsiness, hallucinations, euphoria, headache, hyperaesthesia, hypoaesthesia, lightheadedness, lethargy, nervousness, psychosis, seizure, slurred speech, unconsciousness, somnolence, nausea, vomiting, metallic taste, tinnitus, disorientation, dizziness, paraesthesia, resp depression and convulsions. Patch: Bruising, depigmentation, petechiae, irritation. Ophth: Conjunctival hyperaemia, corneal epithelial changes, diplopia, visual changes.
Potentially Fatal: Hypotension and bradycardia leading to cardiac arrest.

Symptoms: Severe hypotension, asystole, bradycardia, apnoea, seizures, coma, cardiac arrest, resp arrest and death. Management: Maintain oxygenation, stop convulsion and support the circulation.

May increase serum levels w/ cimetidine and propranolol. Increased risk of cardiac depression w/ β-blockers and other antiarrhythmics. Additive cardiac effects w/ IV phenytoin. Hypokalaemia caused by acetazolamide, loop diuretics and thiazides may antagonise effect of lidocaine. Dose requirements may be increased w/ long-term use of phenytoin and other enzyme-inducers.

Decreased levels w/ St John's wort.

IM admin of lidocaine increases creatine phosphokinase levels interfering w/ diagnosis of MI.

Lidocaine is an amide type local anaesth. It stabilises the neuronal membrane and inhibits Na ion movements, which are necessary for conduction of impulses. In the heart, lidocaine reduces depolarisation of the ventricles during diastole and automaticity in the His-Purkinje system. Duration of action potential and effective refractory period are also reduced.
Onset: 45-90 sec (IV); approx 4 hr (transdermal); 20 sec to 5 min (ophth).
Duration: 10-20 min (IV); 5-30 min (ophth).
Absorption: Readily absorbed from the GI tract, mucous membranes, damaged skin, inj sites, including muscle; poor absorption through intact skin. Time to peak plasma concentration: 11 hr (transdermal) following application of 3 patches.
Distribution: Crosses the placenta, blood-brain barrier and enters breast milk. Protein-binding: 60-80% (α₁-acid glycoprotein).
Metabolism: Undergoes rapid metabolism and approx 90% is dealkylated to monoethylglycinexylidide and glycinexylidide. First-pass metabolism is extensive.
Excretion: Via urine (<10% unchanged, approx 90% as metabolites). Elimination half-life (biphasic): Initial: 7-30 min; terminal: 1.5-2 hr.

Epidural: Store below 25°C. Intramuscular: Store below 25°C. Intraspinal: Store below 25°C. Intravenous: Store below 25°C. Mouth/Throat: Store below 25°C. Ophthalmic: Store below 25°C. Parenteral: Store below 25°C. Rectal: Store below 25°C. Topical/Cutaneous: Store below 25°C. Transdermal: Store below 25°C. Urethral: Store below 25°C.

Anaesthetics- local & general / Cardiac Drugs

R02AD02 - lidocaine ; Belongs to the class of local anesthetics used in throat preparations.
C01BB01 - lidocaine ; Belongs to class Ib antiarrhythmics.
D04AB01 - lidocaine ; Belongs to the class of topical anesthetics used in the treatment of pruritus.
N01BB02 - lidocaine ; Belongs to the class of amides. Used as local anesthetics.
S01HA07 - lidocaine ; Belongs to the class of local ophthalmologic anesthetics.
C05AD01 - lidocaine ; Belongs to the class of local anesthetics. Used in the topical treatment of hemorrhoids and anal fissures.
S02DA01 - lidocaine ; Belongs to the class of analgesic and anesthetic agents used as otologicals.