ACTION AND MECHANISM

- Analgesic. Capsaicin, applied topically, triggers local irritation, which manifests symptomatically as erythema and a burning sensation, sometimes with itching.

Capsaicin is a highly selective agonist of the transient receptor potential channel vanilloid 1 (TRPV1). The initial effect is the activation of TRPV1-expressing cutaneous nociceptors, producing a sharp pain and erythema caused by the release of vasoactive neuropeptides. Following exposure to capsaicin, cutaneous nociceptors lose some of their sensitivity to various stimuli. These delayed effects of capsaicin are often referred to as "desensitization" and are thought to underlie pain relief. The sensations of TRPV1-expressing cutaneous nerves are expected to remain unaffected, including their ability to detect mechanical and vibratory stimuli. Capsaicin-induced alterations in cutaneous nociceptors are reversible, and normal function (detection of noxious sensations) has been reported and observed to recover within a few weeks in healthy volunteers.

SPECIAL WARNINGS

- If symptoms persist for more than 7 days or irritation or worsening occurs, the patient's clinical condition should be evaluated.

PATIENT ADVICE

- Avoid contact with eyes and mucous membranes.

- Use only on intact skin, not on open wounds, mucous membranes or eczematous skin.

- Do not apply simultaneously to the same area as other topical preparations (e.g., other rubefacients or pain relief gels)

- Do not use for prolonged periods or on large areas.

- Wash your hands after each application.

- Do not use this dressing if you are pregnant, planning a pregnancy or breastfeeding, without first consulting a doctor.

- It is recommended not to scratch the application area to avoid skin damage.

- The application of other heat sources should be avoided during treatment. Treatment should be discontinued if excessive heat is felt.

- Consult your doctor before using the dressing if the pain is accompanied by skin redness, swelling or heat in the joints, persistent joint discomfort, severe back pain radiating to the legs, associated or not with neurological syndromes such as numbness and tingling.

CONTRAINDICATIONS

- Hypersensitivity to capsaicin, to the fruits of the genus Capsicum (hot peppers) or to any of the components of this medicine.

PREGNANCY

Prenatal treatment of rats with high subcutaneous doses of capsaicin (50 mg/kg) resulted in functional neuronal defects; furthermore, neonatal treatment delayed body growth and sexual maturation, reduced mating frequency, and decreased the number of pregnancies. High subcutaneous doses of capsaicin were not teratogenic in rats. However, there is evidence that capsaicin crosses the placenta and exerts a toxic effect on the peripheral nerves of fetuses, causing significant depletion of substance P in the immunoreactive nerve fibers of the dorsal horn of the spinal cord.

The safety of this drug has not been established in pregnant women because there is no experience of its use during pregnancy.

The use of this medication is only acceptable in the absence of safer therapeutic alternatives.

PHARMACOKINETICS

In vitro release studies with the medicated patch have shown that the amount of capsaicin released during an application lasting up to 8 h (approximately 35% of the capsaicin content) is capable of producing an analgesic effect in clinical and preclinical studies.

Animal data indicate that the systemic bioavailability of topically applied capsaicin is between 27 and 34%.

The absorption rate of capsaicin through the skin is consistent with the values ​​found in the scientific literature for semi-solid preparations for topical application.

In vitro studies have shown that capsaicin is absorbed percutaneously. The absorption rate through isolated rat skin is between 7 and 11 µg/cm²/h.

The absorbed capsaicin is metabolized mainly in the liver and eliminated, in the form of metabolites, through urine and feces.

INDICATIONS

- Symptomatic relief of localized [MYALGIA] and [MUSCULOSKELETAL PAIN].

INTERACTIONS

- Not recommended for use in conjunction with other topical products applied to the same area (even several hours after removing the dressing).

LACTATION

There is no data to support its safety during breastfeeding, so this medication should only be used during breastfeeding after consulting a doctor.

CHILDREN

Its use is not recommended.

GUIDELINES FOR PROPER ADMINISTRATION

* Cream: Apply to the affected area and spread with a light massage to promote absorption of the medication. It is advisable to wash your hands after each application.

POSOLOGY

Topical route:* Cream:- Adults: 3-4 applications/day.

PRECAUTIONS RELATING TO EXCIPIENTS

- Because it contains methyl parahydroxybenzoate, it may cause allergic reactions (possibly delayed).

ADVERSE REACTIONS

- A sensation of skin irritation or burning in the application area (50% of cases). This known reaction is a consequence of the pharmacological action of capsaicin, which releases substance P from peripheral nerve endings and causes it to accumulate in the synapse. It usually disappears or lessens over time as treatment continues at the recommended dose, without the need to interrupt it. Hot water, excessive sweating, or occlusion may intensify this sensation.

- Irritative [ERYTHEMA] and [DRY SKIN] at the application site.

- [SNEEZING], [WEARING] or cough (less than 2%), as a result of inhaling dried cream residue.

- If during the first few days of treatment these stinging sensations (and/or itching or tingling) seem excessive, the treatment should be discontinued.

- Appearance of allergic skin reactions such as [URTICARIA] or [BLISTERS] (0.01%-0.1%). In these cases, treatment should be discontinued.

COMPOSITION

CAPSAICIN: 0.25 MILLIGRAMS
PROPYLENE GLYCOL (EXCIPIENT): 0
METHYL PARAHYDROXYBENZOATE (E-218) (EXC): 0 - SODIUM (SALT)
PROPYL PARAHYDROXYBENZOATE (E-216) (EXC: 0