Local anesthetics: Uses, common brands, and safety info

Local anesthetics are quite common in the medical field. Many people have used these anesthetic agents as they provide regional anesthesia for procedures performed in the office or surgical setting. These procedures are performed by various healthcare providers in fields such as surgery, dermatology, and dentistry. Most people are familiar with the clinical use of local anesthetics; however, there are some preparations that may be used topically for pain management as well. Local anesthetics are popular options as they provide an alternative for pain management where opioids may not be needed or a smaller dosage may be required with certain procedures. The chart below provides some of the more common local anesthetic agents.

*Available in prescription and OTC formulations

Other local anesthetics

• Altacaine (tetracaine HCl)

• Amylocaine

• Aspercreme Lidocaine Foot Pain Creme (lidocaine topical cream)

• Aspercreme Lidocaine No Mess (lidocaine topical solution)

• Aspercreme Lidocaine Pain Relieving Creme (lidocaine topical cream)

• Chlorotekal (chloroprocaine hydrochloride)

• Cinchocaine

• Citanest HCl Plain (prilocaine)

• DentiPatch (lidocaine)

• Dibucaine

• Etidocaine

• EMLA (lidocaine/prilocaine topical)

• Goprelto (cocaine nasal)

• Icy Hot Lidocaine Cream (lidocaine/menthol topical)

• Isocaine (mepivacaine)

• Kovanaze (tetracaine/oxymetazoline nasal)

• (levobupivacaine)

• LidaMantle HC (hydrocortisone/lidocaine topical)

• Lipocaine 5 (lidocaine)

• Niphanoid (tetracaine)

• Numbrino (cocaine nasal)

• Oxybuprocaine

• Posimir (bupivacaine)

• Prilolid (lidocaine-prilocaine)

• Novocain (procaine HCl)

• Salonpas Lidocaine Pain Relieving Gel-Patch (lidocaine topical patch)

• Salonpas Lidocaine Plus (benzyl alcohol/lidocaine topical)

• Sameridine

• Scandonest (mepivacaine)

• Sensorcaine (bupivacaine) 

• Septocaine (articaine)

• Tonicaine

• Ultacan (articaine-epinephrine)

• Vivacaine (bupivacaine-epinephrine)

• Xaracoll (bupivacaine)

• Xylocaine Jelly (lidocaine jelly)

• Xylocaine Solution (lidocaine oronasopharyngeal solution)

What are local anesthetics?

Local anesthetics are a type of anesthesia or pain management drug used by healthcare providers to help minimize pain during surgical procedures. When local anesthesia is provided, there is a loss of sensation (or numbness) to a desired location in the body. In turn, local anesthetics provide temporary pain relief during and sometimes after the procedure. This is usually injected subcutaneously into the skin. These medications allow a variety of invasive procedures to be less painful and more tolerable for patients in both outpatient and inpatient settings. Many procedures performed with regional anesthesia also provide sedation to maximize the comfort of patients. Local anesthetics are usually the preferred treatment for minor procedures as they are not as strong as general anesthesia and do not have the capability to make you fall asleep.

How do local anesthetics work?

The mechanism of action for local anesthetics includes inhibition of sodium channels temporarily. This is responsible for transmitting nerve impulses to nerve fibers in certain tissues. The pharmacokinetics for this type of analgesia causes the improper depolarization of pain receptors. As a result, there is a reduction or elimination of sensation to a designated area in the body where the medication was applied. 

The onset and duration of action of local anesthetics are influenced by several factors, but the most important factors are the pH of the tissue and the pKa of the drug. Anesthesiology research shows that the efficacy of local anesthetics largely depends on the location and size of the area needing to be anesthetized.

The addition of sodium bicarbonate is a pharmacology technique used as a neutralizing additive for local anesthetics. This is known as buffering. It has been shown to reduce injection site pain during infiltration and can be combined with the local anesthetic alone or in combination solutions that include epinephrine.

Local anesthetics cause vasodilation resulting in rapid diffusion away from the site of action. This means the medication may have a very short duration of action when these drugs are administered alone. This diffusion can be reduced by the addition of a vasoconstrictor. Epinephrine is another common additive for local anesthetics as it works as a vasoconstrictor that restricts blood flow. This slows bleeding, which is important in highly vascular procedures, such as those seen in dentistry. Its vasoconstriction allows the analgesia to have a longer duration of action providing longer pain relief.

What are local anesthetics used for?

There are many common uses for local anesthetics such as :

• Removal of warts

• Removal of moles

• Removal of skin lesions or cancerous cells

• Removal of tooth

• Filling of tooth

• Root canal

• Removal of ingrown toenail

• Gum work

• Canker sores

• Cataract surgery

• Lumbar puncture

• Pain injections

• Open wounds 

• Sore throat

• Minor burns

• Poison ivy

• Bug bites

• Hemorrhoids

• Laceration repair

• Removal of sutures

• Laser treatments

• Intravenous insertion

• Catheter insertion

• Endoscopy

• Epidurals

• Spinal anesthesia

• Cesarean section

• Postoperative pain

Types of local anesthetics 

There are various preparations for local anesthetics. They are most commonly seen as a solution for local infiltration to the subcutaneous tissues or intravenous medication for peripheral nerve blocks. Clinical use may also be seen with creams, patches, sprays, ointments, and gels. Structurally, local anesthetics have specific features. These include a lipophilic group joined by an amide or ester that is linked to a carbon chain that is joined to a hydrophilic group. Local anesthetics are further categorized into two classes: esters and amides.

Ester local anesthetics

The anesthesiology of ester local anesthetics involves knowledge of the para-aminobenzoic acid (PABA). When ester drugs are metabolized, they liberate PABA that provides analgesia. This aromatic ring structure is known to cause hypersensitivity with these types of local anesthetics. Reactions are quite rare overall for local anesthesia. Along with the aromatic ring, preservatives found in these medications have also been linked to allergic reactions in local anesthesia. If there is a known allergy to one ester derivative, then there is usually an allergy to all.

Examples of ester local anesthetics: Alcaine, benzocaine, Clorotekal, Goprelto 

Amide local anesthetics

Non-PABA-based derivatives are known as amide local anesthetics. Because they do not metabolize the PABA like esters, these local anesthetics have less of a likelihood of causing allergic reactions. In contrast to esters, if there is an allergy to one amide local anesthetic this does not mean there is an allergy to all. Many amide local anesthetics can also be combined with adrenaline (epinephrine) which prolongs the effects of the peripheral nerve blocks, decreases bleeding during procedures, and increases the intensity of the peripheral nerve block by reducing its systemic absorption.

Examples of amide local anesthetics: Carbocaine, Marcaine, Xylocaine

Who can take local anesthetics?

Local anesthetics are relatively safe for men, women, seniors, and children. Considerations should always be taken for the overall health of the person that will be receiving the medication. Weight considerations are important in children to avoid overdose. Seniors may have lower renal and hepatic functionality so the maximum doses should be known prior to administering. Cardiovascular concerns may also arise with the use of epinephrine. Patients should inform their healthcare provider of any known reaction to local anesthetics in the past to help reduce the incidence of adverse reactions. 

Are local anesthetics safe?

Recalls

• Fresenius Kabi’s Recall of Ketorolac Results In QuVa Pharma® Recall of Compounded Sterile Product (R.E.C.K.)

  , April 2020

Restrictions

Providers may avoid using local anesthetics or use caution if patients have:

• Known hypersensitivity to the medication

• Hypersensitivity to sulfites

• Infection at the injection site

• Heart block without pacemaker

• Continuous infusion in a joint

Also, certain drugs are not appropriate for labor and delivery anesthesia.

Can you use local anesthetics while pregnant or breastfeeding?

Local anesthetics are safe to use while pregnant or breastfeeding. Lidocaine and prilocaine have the best rankings through the Food and Drug Administration. Lidocaine typically is the preferred medication due to its low concentrations and its safety rating. 

Are local anesthetics controlled substances?

Local anesthetics are not controlled substances, as their pharmacology is not habit-forming and does not pose any risk of dependency on the medication.

Common local anesthetics side effects

Many common side effects of local anesthetics include:

• Lightheadedness

• Anxiety

• Dizziness

• Vomiting

• Local redness

• Local swelling

• Abnormal sensations

• Hypersensitivity reaction

• Tinnitus

• Perioral numbness

• Metallic taste

• Altered mental status

• Muscle twitching

• Nausea

• Headache

• Fever

• Rigors

• Pruritus

• Drowsiness

• Restlessness

• Blurred vision

• Tremor

• Paleness

• Confusion

• Euphoria

• Lethargy

• Agitation

• Hot sensation

• Cold sensation

• Hallucinations

• Stinging sensation

• Burning sensation

• Twitching

More serious adverse effects to look for include:

• Anaphylactic reaction

• Hypertension

• Hypotension

• Cardiac arrest

• Seizures

• Arrhythmias

• Coma

• Familial malignant hyperthermia exacerbation

• Unconsciousness

• Respiratory arrest

• Neurotoxicity

• Heart block

• Bronchospasm

• Systemic toxicity of central nervous system (CNS)

• Methemoglobinemia

How much do local anesthetics cost?

Local anesthetics are usually purchased by healthcare facilities or other healthcare providers for the use of patients. Local anesthetics can be as low as $12 for a bottle of solution or as high as $765. There are some topical preparations that may be available to non-healthcare professionals for temporary pain relief of minor health conditions. In such cases, you can use a SingleCare savings card to save money on local anesthetics and other prescription drugs.