Vantas

Vantas contains the substance histrelin, an artificial analogue of natural LHRH.

Indications Vantas

It is used in palliative therapy of locally advanced prostate cancer.

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Release form

Released as an implant in a 50 mg bottle. The package contains 1 bottle of the medicine, which is accompanied by 1 syringe applicator.

Pharmacodynamics

After implantation, histrelin is released inside the tissue, which causes suppression of LH secretion by the pituitary gland. This process then leads to a decrease in the testosterone level in men inside the plasma. This effect disappears after completion of treatment. At the initial stage of therapy, Vantas, like other LHRH agonists, is able to temporarily increase the plasma level of testosterone.

One month after the implantation procedure, testosterone levels drop to the post-castration limit and then remain at a low level for as long as the implant is in the body. This suppression causes prostate tumor regression and also improves the general health of most patients.

The implant is inserted subcutaneously and then remains in place for 12 months. The active ingredient is released through a hydrogel reservoir at a dosage of approximately 50 mcg of the substance per day.

This reservoir is responsible for the rate of diffusion of the substance into the surrounding space together with the water base. At the same time, the hydrogel does not dissolve, and its composition resembles adipose tissue, as a result of which it has good biocompatibility, reducing mechanical irritation of the surrounding tissues with cells. At the same time, it has low surface tension in in vivo tests, which helps to reduce the protein ability to absorb and accumulate on the surface of the inserted implant. This function is very important because it prevents the occurrence of thrombosis, as well as the occurrence of biological rejection of the drug by the body.

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Dosing and administration

The recommended dosage of the drug is 1 implant for a period of 12 months. It is injected subcutaneously into the inner part of the upper arm. Approximately 50 mcg of histrelin acetate is released into the body daily.

After 12 months of use, the element must be removed. Along with the removal of the implant, a procedure for installing a new one is performed to continue the treatment course.

When inserting and removing the drug, it is necessary to use sterile gloves and also to follow the existing rules of asepsis to prevent the occurrence of infection.

Determining the area of the body where the injection will be performed.

The patient must be placed on his back, and his non-working arm (if the person is right-handed, then his left arm) must be bent to gain access to the inner part of the shoulder. Then support it with pillows to calmly hold it in the specified position. The suitable area for introduction is approximately in the middle between the elbow and shoulder joints - on the fold between the 2- and 3-headed shoulder muscles.

Preparation of the device used for the implantation procedure.

The implantation device must be prepared before the procedure of preparing the insertion area. First, it is taken out of the sterile bag. It has a special cannula that extends the entire length of the device. You can check this by watching the green reverse button, which must be fully extended forward in the direction of the cannula and away from the device handle.

Next, remove the cap from the bottle and pull out the stopper, then use a Mosquito clamp to hook the tip of the medicinal implant. Do not squeeze or clamp the middle area of the implant to prevent its standard shape from being disturbed. Next, insert the implant into the device. After that, it will be located inside the cannula so that only its tip can be seen at the bottom of the cut.

A procedure for subcutaneous insertion of a therapeutic implant.

It is necessary to treat the injection area with a special povidone-iodine solution using a tampon, after which sterile wipes should be applied to the surgical site.

Before the anesthesia procedure, it is necessary to check the patient's tolerance of adrenaline or lidocaine. Then the required amount of anesthetic is administered (starting from the area of the planned incision, and then further, performing infiltration of soft tissues along the entire length of the implanted element (its length is 32 mm)).

After anesthesia, a shallow incision is made on the body using a scalpel – 2-3 mm in the area of the inner part of the shoulder – perpendicular to the length of the biceps brachii muscle.

When inserting the implantation device, it is necessary to hold it by the handle (its tip is inserted into the cut so that the cut of the syringe cannula points upwards), inserting it subcutaneously until the mark indicated on the cannula is reached. Subcutaneous placement of the device is determined by the fact that at the moment of its insertion, a visual lifting of the skin is observed. It is necessary to ensure that the implantation device does not get inside the muscle tissue.

While holding the device in place, you need to simultaneously press the button to remove the lock and pull it all the way out, continuing to hold the device in place. This will allow you to remove the cannula from the skin incision, leaving the implant under the skin. After this, the device is removed from the skin incision. Palpation helps to determine whether the medicinal element has been installed correctly.

The incision is closed by applying 1-2 sutures, the knots of which are directed inside the incision. Then a little ointment containing an antibiotic is applied to it, after which it is sealed with a surgical plaster (2 pieces). Then a gauze bandage (size 10x10 cm) is applied to the procedure site and secured with a bandage.

Removal of the implant, as well as the procedure for installing a new element.

Vantas must be removed from the body after 12 months.

The area where the implant is located can be identified by palpating the area where the incision made a year ago is located. It is often easy to feel. Then you need to press on its distal tip - to determine the location of the proximal part in relation to the previous incision. If difficulties arise in identifying the site of drug placement, it is allowed to use ultrasound in the area of soft shoulder tissues. If it is impossible to detect the implant using ultrasound, an MRI or CT procedure must be performed.

After aseptic treatment of the area, a scalpel incision is made on it - approximately 2-3 mm long - near the tip of the implanted implant to a depth of about 1-2 mm. Often, its tip can be seen through a thin tissue pseudocapsule. If it is impossible to see the element, it is necessary to press on its distal tip and then massage in the direction of the incision. Then an incision is made in the pseudocapsule area - to open the tip of the element. It is grasped using a clamp and then removed.

When introducing a new medication, follow the same instructions as for the first procedure. You can introduce the new substance through the same incision or use the other hand.

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Contraindications

Main contraindications:

• intolerance to histrelin or other additional components of the drug, as well as the GnRH substance, GnRH agonists or octadecanoic acid;
• There is information about anaphylactic reactions due to the use of artificial LHRH or their agonists;
• It is not used in children or women, as there is no information about its medicinal efficacy and safety.

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Side effects Vantas

Using the implant may cause the following side effects:

• invasions with infections: infectious processes on the skin are occasionally observed;
• manifestations in the area of lymph and blood flow: anemia occasionally develops;
• metabolic and endocrine disorders: weight gain or hyperglycemia often occurs. Occasionally, weight loss, hypertestosteronemia with hypercholesterolemia and hypercalcemia are observed, as well as fluid retention and increased appetite;
• mental health problems: libido often decreases, depression or insomnia develops;
• CNS dysfunction: headaches or dizziness mainly occur. Lethargy or tremors occasionally occur;
• manifestations in the cardiovascular system: most often there is a feeling of rushing blood (this is a common reaction when hypotestosteronemia develops). Hyperemia is observed less frequently. Hematomas occasionally occur, and in addition, ventricular extrasystole or tachycardia;
• disorders in the functioning of the respiratory system: dyspnea is mainly observed in the case of physical exertion;
• Gastrointestinal reactions: functional liver disorder or constipation is often observed. Occasionally, abdominal discomfort, nausea and an increase in plasma LDH and AST levels occur;
• skin manifestations: mainly hypertrichosis develops. Sometimes there is increased sweating (mainly at night) and itching;
• disorders of the musculoskeletal system: most often, painful sensations in the limbs or arthralgia appear. Occasionally, pain in the neck or back develops, muscle infiltrates and myospasms are observed;
• urinary system disorders: mainly urinary retention, renal dysfunction or pollakiuria. Occasionally, nephrolithiasis, renal failure, hematuria with dysuria and decreased CC indicators are observed;
• manifestations from the reproductive organs: mainly testicular atrophy, impotence, and also gynecomastia (these reactions are expected with the development of hypotestosteronemia). Sometimes there is a problem with sexual function, increased sensitivity of the mammary glands, pain in the sternum, itching in the genital area and an increase in acid phosphatase in the prostate;
• Local and systemic manifestations: a general state of weakness, asthenia and hypersensitivity often develop. Pain, erythema and hyperesthesia may occur at the injection site. A feeling of cold, malaise and irritability may occasionally occur. Bruises and peripheral edema may appear at the implant insertion site, inflammation and stent occlusion may occur.

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Interactions with other drugs

No pharmacokinetic interaction testing of the drug with other drugs has been performed.

Histrelin causes suppression of the hypothalamic-pituitary system. This circumstance must be taken into account during diagnostic procedures regarding the functioning of the gonadal, gonadotropic and pituitary systems, which are performed during or after treatment with Vantas.

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Storage conditions

The implant should be stored in a dark place at a temperature of 2-8°C. The device for performing the implantation should also be stored in a dark place at a temperature of 20-25°C. It is prohibited to freeze the medicine and the device.

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Shelf life

Vantas is suitable for use for a period of 2 years from the date of manufacture of the medicine.

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