Iressa

Iressa has an antitumor effect, suppressing the activity of tyrosine kinase - the endings of a factor that stimulates the growth of the epidermis, which is found in most of the bulk neoplasms. The effect of the drug is aimed at reducing the growth rate of a neoplasm, preventing the formation and spread of metastases, and in addition to reducing the rate of angiogenesis and increasing the rate of apoptosis of the formed tumor.

By preventing the growth of neoplasms, the drug also potentiates the effectiveness of hormonal, radiation and chemotherapy substances. [1]

Indications Iressa

It is used to reduce the rate of development of non-small cell tumors of a malignant nature in the bronchi and lungs , as well as metastatic forms of pulmonary carcinoma .

The drug is effective in treating oncological pathologies and resistance of disease-causing cells in relation to the effect of chemotherapy with the use of platinum substances.

Release form

The release of a therapeutic agent is carried out in tablets with a volume of 0.25 g, 10 pieces each inside a cell pack; inside the package there are 3 such packs.

Pharmacokinetics

Absorption.

After oral administration, absorption is rather slow. Plasma Cmax values are noted over a period of 3-7 hours. [2]

Indicators of absolute bioavailability are on average 59%. Eating food does not change the bioavailability of drugs. At a gastric pH of more than 5, the bioavailability of gefitinib decreased by 47%.

Distribution processes.

Continuous intake of the drug once a day causes an increase in concentration by 2-8 times (in comparison with 1-time use). The Css level is noted after consuming 7-10 servings.

The Vd values of gefitinib after reaching Css are equal to 1400 liters - this indicates that Iressa is distributed extensively inside the tissues.

Protein synthesis (with α1-glycoprotein and serum albumin) is approximately 90%.

Exchange processes.

Gefitinib is involved in oxidative metabolic processes with the participation of the CYP3A4 isoenzyme.

The metabolic processes of gefitinib are realized in 3 ways: metabolism affecting the N-propylmorpholine subgroup, demethylation of the quinazoline part of the methoxyl subgroup, and the oxidative form of dephosphorylation of the halogenated phenyl group.

The main degradation product recorded within human blood plasma is O-desmethylgefitinib. It has a less pronounced activity in comparison with gefitinib (14 times) relative to cell growth stimulated by the epidermal growth factor, which is why it is unlikely to have a significant effect on the clinical effect of gefitinib.

Excretion.

Systemic indicators of intraplasmic clearance of gefitinib are about 0.5 liters per minute. The average half-life is 41 hours. Most of the drug is excreted in the faeces. Excretion in the urine is less than 4% of the accepted dosage.

Dosing and administration

The medicine is taken orally. The tablets must be taken at the same time, without reference to food intake.

The medication is used in 1 tablet (0.25 g), once a day. If you skip the next application, you should complete it at least 12 hours before the next. You can not use 2 tablets at once in 1 dose.

If the patient is not able to swallow a whole tablet himself, it can be dissolved in still water (0.1 l), which he will drink (or enter it through a tube). To get the full effect, after emptying the glass, it must be washed, refilled with water, and given to the patient to drink.

People with severe diarrhea, interstitial pneumonia, signs of allergies and other side symptoms during therapy can take a break in the use of drugs (no more than 14 days). Further, the therapy is performed in a standard mode.

• Application for children

Prescribing a medication in pediatrics is prohibited.

Use Iressa during pregnancy

You can not use Iressa during pregnancy, as well as during breastfeeding.

Contraindications

It is contraindicated to use the medicine if you are allergic to the elements that make up it.

Caution is required in the presence of such concomitant diseases: pneumoconiosis, idiopathic form of pulmonary fibrosis, increased levels of liver enzymes and bilirubin, as well as a hereditary form of hypolactasia. If the patient has a drug-induced, interstitial, or post-radiation form of pneumonia, therapy should be performed under supervision.

Side effects Iressa

Often, the use of a medication causes such side symptoms: dehydration, stomatitis, diarrhea, dry mucous membranes and epidermis, as well as itching and rashes (acne or pustular). In addition, there is nausea, asthenia, anorexia, vomiting with a tendency to bleed (from the nose or hematuria), conjunctivitis, xerophthalmia, blepharitis, increased AST activity with ALT, interstitial pneumonia (if you ignore the increase in manifestations, death is possible), hyperthermia and change in shape nails. Iressa affects some tests: urinary protein levels and blood creatinine and bilirubin levels increase.

Occasionally, when using drugs, pancreatitis, TEN, hepatitis, hypocoagulation, urticaria, Quincke's edema, MEE or a malignant form of exudative erythema, treatable erosion in the cornea, eyelash growth disorder, epidermal vasculitis and liver failure appear.

Overdose

In case of an overdose, severe digestive dysfunctions, epidermal rashes and an increase in the intensity of side effects are observed.

Interactions with other drugs

Taking the medication together with inducers of CYP3A4 isoenzyme production (rifampicin, carbamazepine, barbiturates and phenytoin with St. John's wort tincture) significantly weakens the medicinal effect of gefitinib.

The effect of Iressa is potentiated by 80% when administered with inhibitors of the CYP3A4 isoenzyme (for example, itraconazole).

The likelihood of neutropenia increases when combined with vinorelbine.

In the case of an increase in gastric pH under the influence of certain drugs, the activity of the drug is weakened by 45-50%.

Use in combination with anticoagulants increases the likelihood of bleeding. It is necessary to combine these drugs, controlling the blood clotting rates.

Storage conditions

Iressa should be kept at temperatures not exceeding 30oC.

Shelf life

Iressa can be used within a 4-year period from the date of manufacture of the pharmaceutical product.