# Lidocaine Dose Calculator

We created this **lidocaine dose calculator** to help you determine **the maximum allowable subcutaneous dose of lidocaine.**

Lidocaine is the most commonly used local anesthetic in many medical specialties. Although lidocaine has a good safety margin before it causes toxicity, it is crucial to be aware of the maximum allowable subcutaneous dose to avoid serious health complications. Whether you're a medical professional or a patient, come along and learn how to calculate **the max dose of lidocaine,** how lidocaine works, how the lidocaine dose calculator works, who should not use lidocaine, and more!

❗ **Do not** use the lidocaine dose calculator as the primary guide for dosing. The calculator only helps you determine the **maximum** allowable subcutaneous dose of lidocaine.

## What is lidocaine used for and how does it work?

Lidocaine, sometimes referred to as lignocaine, is **a local anesthetic** mainly used to prevent or alleviate pain caused by **uncomfortable medical procedures** – the physicians also use it to suppress abnormal rhythms of the heart (cardiac arrhythmias). This amino amide-type local anesthetic works by blocking the nerves from sending pain signals. **The effects of lidocaine** usually last at least 20 minutes, and it's half-life (amount of time it takes for a drug's concentration in the blood plasma to reduce by half) is around 90-120 minutes.

Lidocaine is mainly **well-tolerated,** with hypersensitivity reaction being a rare occasion. However, it can reach toxic blood levels, causing direct nerve toxicity at the injection site, as well systemic toxicity affecting the brain.

Although **lidocaine toxicity** depends not only on the total dose administered but also on the **absorption rate,** it is essential to be cautious to avoid administering a toxic dose of lidocaine.

## Lidocaine dosing

Calculating **the maximum allowable subcutaneous lidocaine dose** (without epineprhrine) according to weight is relatively straightforward.

For calculating the maximum allowable dose in **mg,** use the formula below:

`dose(mg) = 4.5 × weight`

where:

`dose(mg)`

– Maximum allowable subcutaneous lidocaine dose according to your weight in**mg**;`4.5`

– Represents maximum allowable subcutaneous lidocaine dose per kg (i.e.,**mg/kg**); and`weight`

– Your weight in kg.

For calculating maximum allowable dose in **ml,** use the following formula:

`dose(ml) = 4.5 × (weight / 10) × (1 / concentration)`

where

`dose(ml)`

– Maximum allowable subcutaneous lidocaine dose according to your weight in**ml**; and`concentration`

– Lidocaine concentration percentage.

## How does lidocaine max dose calculator work?

Now that you know how to calculate the maximum allowable subcutaneous dose of lidocaine, let's discuss **how the lidocaine dose calculator works:**

- Enter the
**weight**in the unit of your convenience. - Chose
**concentration**of lidocaine (0.25%, 0.5%, 0.75, 1%, 1.5%, 2%, 3%, or 4%). - Voila! The calculator will determine the
**maximum allowable subcutaneous dose**of lidocaine in mg and ml.

## FAQ

### What is lidocaine?

Lidocaine is a **local anesthetic,** often used to either **prevent or treat pain** and discomfort from medical procedures, such as surgery, needle punctures, or insertion of the breathing tube.

### How do I calculate max allowable dose of subcutaneous lidocaine based on weight?

To order to calculate the **max allowable dose of subcutaneous (subQ) lidocaine:**

- Take the maximum allowable dose of lidocaine, which is
**4.5 mg/kg**; **Multiply**4.5 by your weight in kg;- That's it! You have calculated the maximum allowable subQ dose of lidocaine in mg.

### How do I calculate maximum allowable volume of subcutaneous lidocaine, if my weight is 75 kg?

To calculate the **maximum allowable volume** of subcutaneous lidocaine:

**Divide**your weight in kg by 10.**Divide**1 by the lidocaine concentration (e.g., 0.25%).**Multiply**the numbers computed in Step 1 and Step 2.**Multiply**the result by the max allowable subcutaneous dose of lidocaine based on weight (ml), which is 4.5.- That's all!
**135 ml**is the maximum allowable subcutaneous dose of lidocaine based on your weight.

### Who should not use lidocaine?

Patients with the following conditions should **avoid** taking lidocaine:

- Hypersensitivity to amide-type local anesthetics;
- Impaired lung function;
- Methemoglobinemia;
- Glucose-6-phosphate dehydrogenase deficiency;
- Wolff-Parkinson-White Syndrome;
- Adams-Stokes syndrome;
- Heart block;
- Cardiogenic shock; and
- Liver problems.