Lavirk 50 Mg/G Skin Gel 1 Tube 5 G + Dosing Pump

Lavirk (50 Mg/G Skin Gel 1 Tube 5 G + Dosing Pump)

ACTION AND MECHANISM

- Antiviral. Acyclovir is a virostatic with a structure analogous to guanosine, which inhibits cellular synthesis of viral DNA.

The antiviral action is manifested only in viruses in the replication phase. This selective action is due to the fact that the first phosphorylation of acyclovir monophosphate involves an enzyme specific to the virus, thymidine kinase, an enzyme for which acyclovir shows 200 times more affinity than for the human enzyme. In cells not infected by the virus, this first phosphorylation is very slow. Subsequent phosphorylations to reach the active form of the drug, acyclovir triphosphate, are carried out by cellular enzymes.

Acyclovir triphosphate is capable of inhibiting viral replication in three ways:

* Selective inhibition of viral DNA polymerase.

* Competition between acyclovir triphosphate and guanosine triphosphate for incorporation into viral DNA.

* Chain interruption upon incorporation into viral DNA.

It is especially active against herpes simplex virus (HSV) types 1 and 2, and varicella zoster virus. In descending order, it also presents in vitro activity against Epstein-Barr virus (EBV), human herpes virus type 6 (HHV-6) and cytomegalovirus (CMV). Against CMV (virus without thymidine kinase) its activity is much lower than that of famciclovir or foscarnet.

PHARMACOKINETICS

- Absorption: acyclovir barely passes through intact skin, reaching undetectable levels (< 0.01 mcg/ml) after administration 4 times a day for 7 days. In the skin of people with herpes zoster, cp of 0.01-0.28 mcg/ml is reached.

- Distribution: low binding to plasma proteins (9-33%). Its Vd is 0.8 l/kg.

- Metabolism: it undergoes partial metabolism due to hydroxylation and oxidation reactions. Two metabolites have been described, 8-hydroxy-acyclovir and 9-carboxymethoxy-methyl-guanine, both inactive.

Enzyme inducing/inhibitory capacity : it does not seem to present significant effects.

- Elimination: mainly in urine in unchanged form. After topical administration, between 0.02-9.4% of the dose is recovered in urine in unchanged form. Its CLr is 173-353 ml/min/1.73 m2 and t1/2 is 2.5-3.3 h.

Pharmacokinetics in special situations :

- Renal failure: an increase in cp has been observed, with values ​​of 0.78 mcg/ml. However, due to its minimal topical absorption it does not seem likely that this is significant.

- Other situations: there are no data available on how age or the degree of liver function could affect the pharmacokinetics of acyclovir after topical administration.

INDICATIONS

Lip:
- Treatment of the symptoms of [HERPES SIMPLE LABIAL], such as itching, stinging or tingling.

POSOLOGY

- Adults: apply a thin layer on the lesions 5 times a day, approximately every 4 hours, omitting the application during sleeping hours at night. To achieve maximum effectiveness, it is important to start treatment as soon as possible, as soon as the first symptoms appear.

- Children and adolescents < 18 years: no dosage adjustment required. Perform under medical supervision.

- Elderly: no dosage adjustment required.

Treatment duration: 5 days. If complete healing has not occurred, extend 5 more days for a total of 10 days. If symptoms worsen or do not improve during this period, reevaluate the diagnosis.

Forgotten dose: administer the next dose at the usual time. Do not double the next dose.

DOSAGE IN KIDNEY FAILURE

No specific dosage recommendations have been made.

DOSAGE IN LIVER FAILURE

No specific dosage recommendations have been made.

RULES FOR CORRECT ADMINISTRATION

Apply to the affected area, massaging gently to promote absorption.

It is recommended to use a finger cot or rubber glove to avoid contagion to other parts of the body. If this is not possible, it is advisable to wash your hands before and after application, as well as avoid rubbing the lesions with hands, towels or other objects to prevent the infection from worsening or being transmitted to other people.

Avoid applying it to mucous membranes, such as the mouth, eyes or vagina, due to the risk of irritation. In case of accidental contact with eyes, wash with plenty of water and consult an ophthalmologist.

ADVICE TO THE PATIENT

- Treatment should be started as soon as possible after the appearance of symptoms.

- Acyclovir does not prevent the transmission of the virus. Therefore, extreme precautions should be taken to reduce the risk of possible contagion, such as avoiding contact of the lesions with hands or other objects, or using condoms in case of genital herpes. However, genital herpes could be transmitted to areas not covered by the condom.

- Check with your doctor if your symptoms worsen or do not improve after using acyclovir for 10 days.

- Avoid applying it to the eyes or mucous membranes, such as the inside of the mouth or vagina.

CONTRAINDICATIONS

- Hypersensitivity to acyclovir, valacyclovir or any other component of the medication.

PRECAUTIONS

- [IMMUNODEFICIENCY]. In severely immunocompromised patients, such as [HIV INFECTION] or patients undergoing [TRANSPLANTATION], the use of topical acyclovir may be insufficient to combat the infection. The use of oral acyclovir should be considered.

SPECIAL WARNINGS

- Treatment should be started as soon as the first symptoms appear.

- Patients with severe infection, severe immunosuppression, or frequent recurrences may require oral acyclovir to control the infection.

- A differential diagnosis is recommended in young children in case of a possible first herpes infection, since the symptoms could be confused with other oral or teething disorders.

INTERACTIONS

They have not been described. It is unlikely due to its minimal absorption.

PREGNANCY

Safety in animals : No harmful effects on pregnancy, embryo-fetal development, parturition or postnatal development have been observed.

Safety in humans : There are no adequate and well-controlled studies in humans. There is very limited data on its use in pregnant women, where no side effects on the fetus have been observed. Its administration is only accepted if there are no safer therapeutic alternatives, and the benefits outweigh the possible risks.

Effects on fertility : No specific studies have been conducted in humans topically. Its systemic administration did not negatively affect sperm (morphology, motility, count).

LACTATION

Safety in animals: no data available.

Safety in humans: Acyclovir is excreted in milk. After administration of 200 mg 5 times a day, concentrations in milk were obtained 0.6-4.1 times the maternal cp, which would mean a dose for the infant of 0.3 mg/kg/24 h. However, it is estimated that due to its poor skin absorption, the levels in milk would be minimal. Its administration is only accepted if there are no safer therapeutic alternatives, and the benefits for the mother outweigh the possible risks to the infant.

CHILDREN

No specific problems have been described in children that require dosage readjustment. It is recommended to use under medical recommendation, especially in < 12 years.

Cold sores are a recurrence of an infection inside the mouth that is usually contracted at an early age. It is recommended to perform a first medical diagnosis in children, since the symptoms of the first infection could go unnoticed or be confused with teething disorders or other oral processes.

ADVANCED AGE

No specific problems have been described in the elderly that require dosage readjustment.

EFFECTS ON DRIVING

It does not seem to present a significant effect.

ADVERSE REACTIONS

Adverse reactions are described according to each frequency interval, being considered very common (>10%), common (1-10%), uncommon (0.1-1%), rare (0.01-0.1%). , very rare (<0.01%) or of unknown frequency (cannot be estimated from the available data).

- Dermatological: infrequent local reactions in the application area, such as a local burning sensation, [PRURITUS], [DRY SKIN], [SKIN PEELING]; rare [ERYTHEMA], [CONTACT DERMATITIS].

- Allergic: very rare [HYPERSENSITIVITY REACTIONS], including [ANGIOEDEMA].

ADVERSE REACTIONS RELATING TO EXCIPIENTS

- This medicine contains propylene glycol, so it can cause [SKIN IRRITATION].

OVERDOSE

Symptoms: Major poisoning is unlikely due to its route of administration. After accidental ingestion of 10 g of cream (500 mg of acyclovir), no symptoms have been described. There have been cases of patients receiving up to 20 g orally, without presenting symptoms.

Measures to take:

- Antidote: there is no specific antidote.

- General elimination measures: although it does not seem necessary to take any measures, acyclovir is eliminated by hemodialysis.

- Monitoring: clinical status of the patient.

- Treatment: symptomatic

Leaflet Lavirk 50 Mg/G Skin Gel 1 Tube 5 G + Dosing Pump