Xylocaine 0.5% Inj, 50ml

Lidocaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby blocking nerve impulse conduction. It primarily acts by reversibly blocking voltage-gated sodium channels in the neuronal cell membrane, preventing depolarization and propagation of action potentials.

Serious Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:

Signs of an allergic reaction:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of methemoglobinemia (a rare but potentially life-threatening condition):
+ Blue or gray discoloration of the lips, nails, or skin
+ Irregular heartbeat
+ Seizures
+ Severe dizziness or fainting
+ Severe headache
+ Excessive sleepiness
+ Fatigue or weakness
+ Shortness of breath
Signs of acidosis (too much acid in the blood):
+ Confusion
+ Rapid breathing
+ Rapid heartbeat
+ Irregular heartbeat
+ Severe stomach pain, nausea, or vomiting
+ Excessive sleepiness
+ Shortness of breath
+ Fatigue or weakness
Other serious side effects:
+ Breathing difficulties, slow breathing, or shallow breathing
+ Lightheadedness, drowsiness, confusion, or blurred vision
+ Slow heartbeat
+ Nervousness or excitability
+ Speech difficulties
+ Abnormal burning, numbness, or tingling sensations
+ Restlessness
+ Anxiety
+ Changes in vision
+ Ringing in the ears
+ Dizziness or fainting
+ Severe headache
+ Twitching
+ Shakiness
+ Seizures
+ Feeling extremely hot or cold
+ Metallic taste
+ Chest pain
+ Mood changes

Additional Side Effects (Injection into the Spine)

If you receive this medication via injection into the spine, you may experience:

Erectile dysfunction
Loss of mobility
Loss of bowel or bladder control
Urination difficulties

Other Side Effects

As with any medication, you may experience side effects that are not severe but still bothersome. If you notice any of the following symptoms, contact your doctor:

Mild side effects that do not go away or bother you
Any new or worsening symptoms

Reporting Side Effects

If you experience any side effects, you can report them to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. You can also contact your doctor for medical advice about side effects.

Before Taking This Medication: Important Information to Share with Your Doctor

To ensure safe treatment, inform your doctor of the following:

Any allergies you have to this medication, its components, or other substances, including foods and drugs. Describe the allergic reactions you experienced.
If you are scheduled to receive this medication via spinal injection, notify your doctor if you have:
+ Heart block
+ Severe bleeding
+ Severe infection
+ An infection at the injection site

It is essential to disclose all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any health problems you are experiencing. This will help your doctor and pharmacist assess potential interactions and ensure safe use of this medication. Do not initiate, stop, or adjust the dosage of any medication without consulting your doctor first.

Important Warnings and Cautions

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.

Risk of Methemoglobinemia
A severe blood disorder called methemoglobinemia has been associated with drugs like this one. Your risk may be increased if you have:
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Heart problems
Lung problems
Are taking certain other medications
Are an infant younger than 6 months of age
If you have a history of methemoglobinemia, notify your doctor.

Sulfite Allergy
If you are allergic to sulfites, consult your doctor, as some products may contain sulfites.

Caution with Daily Activities
Avoid driving and performing tasks that require alertness until the effects of this medication have worn off and you feel fully awake.

Post-Treatment Precautions
If you are discharged before the numbness has resolved, protect the treated area from injury until you have regained sensation.

Special Considerations
If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.
If the patient is a child, use this medication with caution, as the risk of certain side effects may be higher in children.
If you are pregnant, plan to become pregnant, or are breastfeeding, discuss the benefits and risks with your doctor.

Injection (Spinal Administration)
This medication may cause temporary loss of feeling and motor function in the lower half of your body. Do not attempt to get out of bed or perform tasks until sensation and motor function have returned to normal.

Mouth and Dental Procedures
Do not eat while your mouth is numb, as you may accidentally bite your tongue.

• Antiarrhythmics (Class I, III): Increased risk of cardiac depression and toxicity (e.g., amiodarone, procainamide, quinidine, disopyramide).
• Beta-blockers (e.g., propranolol, metoprolol): May decrease hepatic clearance of lidocaine, leading to increased lidocaine levels and toxicity.
• Cimetidine: Inhibits lidocaine metabolism, increasing plasma concentrations and risk of toxicity.
• Other local anesthetics: Additive systemic toxicity.

• CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin): May increase lidocaine levels.
• CYP3A4 inhibitors (e.g., macrolide antibiotics, azole antifungals, protease inhibitors): May increase lidocaine levels.
• Skeletal muscle relaxants: May prolong neuromuscular blockade.
• Phenytoin: May increase lidocaine metabolism (inducer) or increase risk of cardiac depression (additive effect).

• Not specifically identified for minor interactions with significant clinical impact for acute local anesthetic use.

• Lightheadedness
• Dizziness
• Tinnitus
• Perioral numbness
• Metallic taste
• Blurred vision
• Tremors
• Muscle twitching
• Drowsiness
• Confusion
• Seizures
• Bradycardia
• Hypotension
• Cardiac arrest

Lidocaine is classified as Pregnancy Category B. Studies in animals have not shown harm to the fetus, and there are no adequate and well-controlled studies in pregnant women. It is generally considered safe for use during pregnancy when clinically indicated and used at the lowest effective dose.

Lidocaine is excreted into breast milk in small amounts. The amount transferred to the infant is generally considered too small to cause adverse effects. It is rated L2 (Safer) by LactMed.

Pediatric patients, especially infants and young children, are more susceptible to systemic toxicity due to differences in metabolism, distribution, and higher relative doses per body weight. Dosing must be carefully calculated based on weight and age, and the lowest effective dose should be used. Close monitoring for signs of toxicity is crucial.

Elderly patients may have reduced hepatic blood flow and metabolism, leading to increased plasma concentrations and prolonged half-life of lidocaine. They may also be more sensitive to the CNS and cardiovascular effects. Lower doses and careful monitoring are recommended.

• Always aspirate prior to injection to avoid inadvertent intravascular administration, which can lead to systemic toxicity.
• The addition of epinephrine prolongs the duration of action and reduces systemic absorption, allowing for higher total doses, but should be avoided in areas with end-arterial circulation (e.g., fingers, toes, nose, penis, ears) due to risk of ischemia.
• Signs of systemic toxicity often begin with CNS symptoms (e.g., perioral numbness, tinnitus, lightheadedness) before progressing to more severe CNS (seizures) and cardiovascular effects (bradycardia, hypotension, cardiac arrest).
• Lipid emulsion therapy (Intralipid) is an important antidote for severe local anesthetic systemic toxicity (LAST).
• The 0.5% concentration is typically used for large volume infiltration or nerve blocks where a less dense block is acceptable, or when a large volume is needed to cover a wide area without exceeding the maximum mg/kg dose.

• Bupivacaine (longer duration of action)
• Ropivacaine (less cardiotoxic than bupivacaine, similar duration)
• Mepivacaine (similar onset and duration to lidocaine, less vasodilation)
• Procaine (ester-type local anesthetic, shorter duration)
• Chloroprocaine (ester-type local anesthetic, very short duration)

If your symptoms or health problems do not improve or worsen over time, it is essential to contact your doctor for further guidance. To ensure safe use, never share your medication with others, and do not take medication prescribed to someone else. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion.

Proper disposal of unused or expired medications is crucial. Do not dispose of them by flushing down the toilet or pouring down the drain unless specifically instructed to do so. If you are unsure about the correct disposal method, consult your pharmacist for advice. Many communities have drug take-back programs that provide a safe and environmentally friendly way to dispose of unwanted medications.

Some medications may come with an additional patient information leaflet. Check with your pharmacist to see if this applies to your prescription. If you have any questions or concerns about your medication, do not hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider.

In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide detailed information about the overdose, including the name of the medication, the amount taken, and the time it occurred, to ensure prompt and effective treatment.