Rapydan: Uses, Dosage & Side Effects

What Is Rapydan and What Is It Used For?

Rapydan is an innovative topical anaesthetic delivery system that combines two well-established local anaesthetic agents – lidocaine and tetracaine – in a self-contained medicated plaster with an integrated heating element. Developed to address the clinical need for rapid, reliable, and convenient dermal anaesthesia, Rapydan represents a significant advancement over traditional topical anaesthetic creams and patches that often require longer application times or supplementary occlusive dressings.

Each Rapydan plaster contains 70 mg of lidocaine, an amide-type local anaesthetic, and 70 mg of tetracaine, an ester-type local anaesthetic. The combination of these two pharmacologically distinct agents provides complementary anaesthetic action. Lidocaine has a rapid onset of action and excellent tissue penetration, while tetracaine provides a longer duration of anaesthesia and enhanced depth of skin numbing. Together, they block voltage-gated sodium channels in sensory nerve fibres, preventing the initiation and conduction of pain signals from the treated skin area to the brain.

The defining feature of Rapydan is its Controlled Heat-Assisted Drug Delivery (CHADD) technology. The plaster contains a self-activating heating element composed of iron powder, activated charcoal, sodium chloride, and wood flour encapsulated in a filter paper pouch. When the plaster is removed from its airtight sealed packaging, the heating element begins an oxygen-dependent exothermic reaction. This raises the skin surface temperature by approximately 5°C above baseline (to a mean temperature of 26–30°C, with a maximum of approximately 40°C), which enhances percutaneous absorption of both lidocaine and tetracaine by increasing skin permeability and local blood flow. This thermal enhancement allows Rapydan to achieve effective dermal anaesthesia within 30 minutes – faster than many conventional topical anaesthetic formulations that typically require 45–60 minutes or longer.

Rapydan is indicated for surface anaesthesia of intact skin prior to procedures that may cause pain through the skin surface. The most common clinical applications include:

• Venipuncture: Blood sampling and blood donation, where Rapydan numbs the insertion site to minimize discomfort during needle entry through the skin.
• Intravenous cannulation: Insertion of intravenous lines for fluid administration, medication delivery, or blood transfusions, particularly valuable in patients who require repeated cannulation.
• Superficial surgical procedures: Minor dermatological procedures, biopsies, suturing of superficial wounds, and removal of small skin lesions where full-depth tissue anaesthesia is not required.
• Vaccination and injection procedures: Reducing pain associated with subcutaneous or intramuscular injections, particularly helpful in paediatric settings and for patients with needle phobia.
• Port-a-cath access: Numbing the skin over implanted venous access devices before needle insertion, commonly used in oncology patients undergoing chemotherapy.

Rapydan is authorised across the European Economic Area and is available under various trade names including Rapydan (most countries), Ralydan (Denmark and Norway), and Velocaine (Hungary). The product is manufactured by Eurocept International BV and is supplied as individual plasters, each packaged in a sealed airtight pouch to prevent premature activation of the heating element. It is an oval, light-brown plaster measuring approximately 8.5 cm × 6.0 cm with a removable opaque plastic tray that protects the drug-containing surface during handling.

What Should You Know Before Using Rapydan?

Contraindications

There are specific situations where Rapydan must not be used. Understanding these absolute contraindications is essential for safe use of this medicated plaster.

• Allergy to lidocaine or tetracaine: Do not use Rapydan if you are allergic (hypersensitive) to either lidocaine or tetracaine, to sodium borate, or to any of the other excipients in the product (see composition section). Allergic reactions to local anaesthetics can range from localised skin reactions to severe anaphylaxis.
• Allergy to other local anaesthetics: If you are allergic to other local anaesthetics of either the amide type (such as bupivacaine, ropivacaine, or mepivacaine) or the ester type (such as procaine or benzocaine), you should not use Rapydan, as cross-reactivity may occur.
• Allergy to para-aminobenzoic acid (PABA): Tetracaine is metabolised in the body to para-aminobenzoic acid. If you have a known allergy to PABA or PABA-containing compounds (found in some sunscreens and cosmetics), you must not use Rapydan.
• Damaged or irritated skin: Rapydan must not be applied to skin that is broken, wounded, inflamed, or otherwise damaged. Application to compromised skin could result in excessive systemic absorption of the active substances, increasing the risk of toxicity.
• Mucous membranes: Do not apply Rapydan to mucous membranes such as the inside of the mouth, nose, eyes, or genital areas. These surfaces have much higher permeability than intact skin, which could lead to rapid systemic absorption and toxicity.

Warnings and Precautions

Before using Rapydan, consult your doctor or pharmacist if any of the following conditions apply to you:

• Impaired liver function: Lidocaine is extensively metabolised by the liver. Patients with significant hepatic impairment may have reduced clearance of lidocaine, leading to higher plasma concentrations and an increased risk of systemic toxicity. Your doctor may need to limit the number of plasters used or extend the interval between applications.
• Impaired kidney function: While the kidneys are not the primary route of elimination for either lidocaine or tetracaine, renal impairment may reduce the excretion of metabolites. Caution is warranted in patients with significantly impaired renal function.
• Heart disease: Lidocaine has class Ib antiarrhythmic properties and can affect cardiac conduction at high systemic concentrations. Patients with severe cardiac disease, particularly those with impaired cardiac conduction or heart failure, may be at increased risk from systemic absorption. While the risk from topical application is very low compared to injectable lidocaine, caution is still recommended.
• Acute illness or debilitation: If you are acutely ill or have a reduced general health status, you may be more susceptible to the effects of lidocaine and tetracaine. Your doctor should assess whether Rapydan is appropriate for your current condition.
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency: Patients with G6PD deficiency may be at greater risk of methaemoglobinaemia from local anaesthetic exposure, although this risk is primarily associated with higher doses than those delivered by topical application.

Pregnancy and Breastfeeding

The safety of Rapydan during pregnancy has not been fully established through adequate and well-controlled studies. Both lidocaine and tetracaine are known to cross the placental barrier. While the systemic absorption from a single topical application is relatively low, the decision to use Rapydan during pregnancy should be made by a healthcare professional who can weigh the benefits of the procedure requiring anaesthesia against any potential risks to the developing foetus.

Both lidocaine and tetracaine may be excreted in breast milk, although the amounts transferred from topical application are expected to be very small. Your doctor will decide whether Rapydan can be used during breastfeeding, taking into account the clinical need for the procedure and the low systemic exposure from topical use. If you are pregnant, planning a pregnancy, or breastfeeding, always inform your healthcare provider before using any medication.

Driving and Operating Machinery

Rapydan has no known effect on the ability to drive vehicles or operate machinery. The local anaesthetic effect is confined to the small area of skin where the plaster was applied, and systemic absorption at recommended doses is insufficient to cause central nervous system effects such as drowsiness, dizziness, or visual disturbances. You can safely drive or operate machinery after using Rapydan, provided you do not experience any unexpected side effects.

How Does Rapydan Interact with Other Drugs?

Although Rapydan delivers its active ingredients topically with relatively low systemic absorption, drug interactions are possible because both lidocaine and tetracaine enter the systemic circulation to some extent after application. The potential for clinically significant interactions increases when multiple plasters are used simultaneously, when application times are prolonged, or when other sources of the same active substances are used concurrently.

Major Interactions

The following interactions have been identified as potentially clinically significant and require careful consideration by the prescribing physician:

Other Interactions to Consider

In addition to the antiarrhythmic medications listed above, the following interactions should be kept in mind:

• Other lidocaine-containing products: Concurrent use of Rapydan with other products containing lidocaine (such as lidocaine patches, sprays, gels, creams, or injectable lidocaine) increases the total body exposure to lidocaine and the risk of systemic toxicity including central nervous system and cardiovascular effects.
• Other tetracaine-containing products: Similarly, simultaneous use of other tetracaine-containing preparations (eye drops, sprays, or topical formulations) adds to the total tetracaine exposure and raises the risk of adverse effects.
• CYP1A2 and CYP3A4 inhibitors: Lidocaine is metabolised primarily by the hepatic cytochrome P450 enzymes CYP1A2 and CYP3A4. Potent inhibitors of these enzymes (such as fluvoxamine, ciprofloxacin, ketoconazole, itraconazole, and erythromycin) may reduce lidocaine clearance and increase plasma levels, though the clinical significance of this interaction with topical administration is likely minimal.
• Cholinesterase inhibitors: Tetracaine is hydrolysed by plasma cholinesterases. Medications that inhibit cholinesterase activity (such as donepezil, rivastigmine, galantamine, or organophosphate insecticides) could theoretically prolong the effects and increase the toxicity of tetracaine.

What Is the Correct Dosage of Rapydan?

Rapydan should always be used exactly as directed by your doctor or healthcare professional. The plaster must be applied to clean, intact, dry skin for a full 30 minutes before the planned procedure to allow adequate anaesthetic penetration. Each plaster is for single use only and must be used immediately after opening the sealed pouch, as the heating element begins its exothermic reaction upon exposure to air.

Adults

Children and Adolescents (aged 3 years and older)

Step-by-Step Application Instructions

Follow these instructions carefully each time you use Rapydan to ensure optimal anaesthetic effect:

1. Prepare the skin: Ensure the application site is clean, dry, and free of oils, creams, or other products. The skin must be intact and undamaged.
2. Open the pouch: Tear open the heat-sealed foil pouch and remove the plaster. Do not open the pouch until you are ready to apply the plaster, as the heating element activates immediately upon exposure to air.
3. Remove the plastic tray: Carefully remove the opaque plastic tray from the plaster. Do not touch the round white drug-containing area in the centre of the plaster.
4. Position the plaster: Place the plaster so that the round white drug-containing area covers the treatment site where the procedure will be performed.
5. Press around the edges: Press only around the outer edges of the plaster to secure it firmly to the skin. Ensure a tight seal around the entire perimeter.
6. Press the centre gently: Gently press the centre of the plaster to ensure good contact between the drug layer and the skin surface.
7. Wait 30 minutes: Leave the plaster in place for exactly 30 minutes. Take care that the plaster does not fall off or become dislodged during this time.
8. Remove and clean: Remove the plaster and thoroughly clean the application site before the procedure. If the procedure is being performed by a healthcare professional, let them remove the plaster unless instructed otherwise.

After Removal of the Plaster

After Rapydan has been removed, the treated skin area will be numb and have reduced sensation. This anaesthetic effect typically persists for a variable period after removal, depending on individual skin characteristics, local blood flow, and the depth of anaesthesia achieved. To prevent accidental injury during this time:

• Do not scratch, rub, or apply pressure to the numbed area.
• Avoid contact with very hot or very cold surfaces until full sensation has returned.
• Be careful with sharp objects near the anaesthetised area.
• Monitor children to ensure they do not inadvertently injure the numbed area.

Overdose

Overdose with Rapydan is unlikely when it is used as directed. However, if the plaster is left on the skin for longer than recommended, or if more plasters are used than prescribed, the risk of serious side effects increases due to greater systemic absorption of lidocaine and tetracaine.

Signs of local anaesthetic systemic toxicity (LAST) may include: lightheadedness, dizziness, visual disturbances, numbness of the tongue, tinnitus (ringing in the ears), tremors, drowsiness, and in severe cases, seizures, respiratory depression, and cardiovascular collapse. If you suspect an overdose, or if a child has accidentally ingested the active substances from a plaster, seek immediate medical attention or contact your local poison control centre.

What Are the Side Effects of Rapydan?

Like all medicines, Rapydan can cause side effects, although not everyone experiences them. The vast majority of side effects associated with Rapydan are localised reactions at the application site, caused by the pharmacological effects of the local anaesthetics on the skin and superficial blood vessels, as well as the mild warming from the CHADD heating element. These local reactions are generally mild, self-limiting, and resolve without treatment after the plaster is removed.

The frequency of side effects is classified using the following standard categories:

Understanding Local Skin Reactions

The very common local reactions (redness, blanching, and swelling) are expected pharmacological effects of the local anaesthetics and the warming component, rather than true adverse drug reactions. Erythema (redness) is caused by vasodilation in response to the mild heating and the direct effects of the anaesthetics on superficial blood vessels. Blanching (paleness) occurs in the central area of the treatment site where the anaesthetic concentration is highest, causing local vasoconstriction. Oedema (swelling) results from increased vascular permeability in the treated area. All three reactions typically resolve within 1–2 hours after plaster removal.

Serious Side Effects

Although extremely rare with topical application at recommended doses, systemic toxicity from lidocaine and tetracaine can theoretically occur, particularly if the product is misused (excessive number of plasters, prolonged application, or application to broken skin). Signs of systemic toxicity may include nervous system effects (numbness around the mouth, metallic taste, tinnitus, visual disturbances, tremors, seizures) and cardiovascular effects (bradycardia, hypotension, cardiac arrest in extreme cases).

Reporting Side Effects

If you experience any side effects, including those not listed above, talk to your doctor or pharmacist. You can also report suspected side effects directly to your national pharmacovigilance authority. In the United Kingdom, reports can be made via the Yellow Card Scheme; in the European Union, through your national reporting system. Reporting side effects helps authorities continuously monitor the benefit-risk balance of medicines.

How Should You Store Rapydan?

Proper storage of Rapydan is essential to maintain the effectiveness of the active ingredients and the integrity of the CHADD heating element. The heating component relies on a controlled chemical reaction with oxygen, which means the product must remain in its sealed airtight pouch until immediately before use.

• Temperature: Store at or below 25°C (77°F). Do not freeze. Do not expose to excessive heat or direct sunlight, as this may affect the stability of the local anaesthetics or cause premature activation of the heating element.
• Keep sealed: Each plaster is individually packaged in a sealed pouch of polyester/aluminium/polyethylene laminate. Do not open the pouch until you are ready to use the plaster.
• Keep out of reach of children: Store Rapydan out of the sight and reach of children. If a child accidentally applies or ingests the product, seek medical attention immediately.
• Check packaging: Do not use Rapydan if you can see that the sealed pouch is damaged, torn, or has been previously opened. A damaged pouch may have allowed air to enter, prematurely activating and exhausting the heating element and reducing the effectiveness of the product.
• Expiry date: Do not use Rapydan after the expiry date stated on the pouch and carton after “EXP”. The expiry date refers to the last day of the indicated month.

Disposal

Used plasters still contain residual active substances and should be disposed of carefully. Fold the used plaster in half with the sticky (drug-containing) side inward so that children and pets cannot come into contact with the medication. Do not flush medicines down the toilet or throw them into household waste unless specifically instructed to do so. Ask your pharmacist about proper medicine disposal in your area. Proper disposal protects both the environment and prevents accidental exposure.

What Does Rapydan Contain?

Active Ingredients

Each medicated plaster contains:

• Lidocaine 70 mg: An amide-type local anaesthetic that provides rapid onset of skin anaesthesia. Lidocaine works by blocking voltage-gated sodium channels in sensory nerve fibres, preventing the transmission of pain signals. It has an excellent safety profile and is one of the most widely used local anaesthetics in clinical practice worldwide.
• Tetracaine 70 mg: An ester-type local anaesthetic that complements lidocaine by providing a longer duration of action and enhanced depth of anaesthesia. Tetracaine is more potent than lidocaine on a weight-for-weight basis and is metabolised by plasma cholinesterases to para-aminobenzoic acid (PABA).

Excipients and Plaster Components

The Rapydan plaster consists of multiple functional layers, each serving a specific purpose in the drug delivery system:

• Backing layer: Polyethylene film coated on one side with acrylate adhesive, providing structural support and holding the plaster together.
• CHADD heating element: Iron powder, activated charcoal, sodium chloride, and wood flour encapsulated in a filter paper pouch. This component generates controlled warmth through an oxygen-dependent exothermic reaction to enhance drug absorption.
• Adhesive film: Polyethylene and acrylate adhesive that secures the plaster to the skin surface.
• Heat-seal foil: Laminate of polyethylene and aluminium, coated with polyester urethane adhesive, forming the outer protective layer.
• Drug layer: Polyvinyl alcohol, sorbitan monopalmitate, purified water, methylparahydroxybenzoate (E218), propylparahydroxybenzoate (E216), and sodium borate coated on a non-woven fabric. This layer contains and releases the active anaesthetic substances.
• Removable tray: Opaque polyethylene tray that protects the drug-containing surface during handling and is removed before application.

Product Description

Rapydan is an oval, light-brown medicated plaster with approximate dimensions of 8.5 cm × 6.0 cm. Each plaster comes with a removable opaque plastic tray that covers the drug-containing surface. The plasters are individually packaged in heat-sealed protective pouches made from a polyester/aluminium/polyethylene laminate to maintain an airtight environment. Available pack sizes include 1, 2, 5, 10, 25, or 50 plasters, though not all pack sizes may be marketed in every country.