Monday, July 13, 2009

Paroxetine (Paroxetine)




Trade names

Pax. Paroxetine. Reksetin.

Subgroup

Selective serotonin inhibitors reverse the seizure.

Action

The main components of psychotropic activity profile is antidepressive and protivotrevozhnoe operation with moderate catalytic (catalytic) effect. The effect is manifested after 10 days.

Mechanism of Action

Inhibits reverse the seizure of serotonin neurons, increases serotoninergicheskuyu transmission in the CNS.

Pharmacokinetics

Completely absorbed in ZHKT. Time achieve Cmax in the blood - 5,2 h. Relationship to plasma proteins - 95%. Intensively metabolized, metabolites do not show pharmacological activity. Approximately 64% ekskretiruetsya the urine and 36% - through ZHKT (unchanged - 2% and 1% respectively). T1 / 2 - 21 am-equilibrium concentration is reached after about 10 days, with daily intake of 30 mg.

Indications

* Depression varying etiology;
* Obsessive-compulsive disorder;
* Panic disorder with agoraphobic and without it;
* Social anxiety disorder / social phobia;
* Generalized anxiety disorder;
* Post-traumatic stress disorder.

Contraindications

* Simultaneously receiving MAO inhibitors, and the period of 14 days after the repeal;
* Simultaneous reception tioridazina;
* Simultaneous administration of drugs containing tryptophan;
* Pregnancy;
* The period of lactation (breastfeeding);
* Childhood and adolescence to 18 years;
* Hypersensitivity to paroxetine and other components of the drug.

Side Effects

Drowsiness or insomnia, tremor, nervousness, increased excitability of central nervous system, the violation of concentration, emotional lability, amnesia, dizziness, paresis of accommodation, the expansion of the pupil, and pain in the eyes, noise and pain in the ears, raising or lowering of blood pressure, syncope, tachycardia or bradycardia, Violations of cardiac conduction, and peripheral blood circulation, cough, rhinitis, dipnoe, tahipnoe, nausea, decreased appetite, indigestion, increased activity of hepatic transaminases, stomatitis, arthralgia, arthritis, dizuriya, poliuriya, urinary incontinence, delayed urination, amenorrhea, dysmenorrhea, miscarriage, breast , violation of ejaculation, reduction of libido and potency, peripheral edema, decrease or an increase in body mass, anemia, leukopenia, allergic reaction (itching, rash, chills).

Rarely - violations of thinking akineziya, ataxia, seizures, hallucinations, giperkineziya, manic or paranoid reactions, deliry, euphoria, big epileptic seizures, aggressiveness, nystagmus, stupor, autism, a decline of visual acuity, cataract, conjunctivitis, glaucoma, exophthalmos, angina, myocardial infarction, disturbance of cerebral circulation, a violation of heart rate, eosinophilia, leukocytosis, limfotsitoz, monotsitoz, gematuriya, nefrourolitiaz, the violation of renal function, dermatitis, nodular erythema, depigmentatsiya.

Interaction

Absorption and pharmacokinetics of the drug did not change at all or changes only partially influenced by food, antacids, digoxin, propranolol, and ethanol.

Combined therapy with lithium preparations should be undertaken with caution and under the control of the concentration of lithium in the blood, because of combined experience in the use of paroxetine and lithium restricted.

Metabolism and pharmacokinetic parameters can be changed while the application of drugs that induce or inhibit the metabolism of protein. With simultaneous application of paroxetine with drugs inhibiting the metabolism of enzymes (tsimetidin) applied dose should be limited to the lower boundary of the normal level. When combined with the use of drugs, inducing metabolism enzymes (carbamazepine, phenytoin, valproat sodium) do not want to change the initial dose paroksetinaa. Follow correct dose should be carried out depending on the clinical effect.

With simultaneous application of paroxetine with drugs metabolized system cytochrome P450 CYP2D6 (tricyclic antidepressants (amitriptyline, nortriptilin, imipramine, dezipramin) fenotiazinovye neuroleptics (tioridazin, perfenazin) and antiaritmicheskie class IC drugs (propafenon, flekainid) and metoprolol), there is increasing their concentrations in blood plasma. The combination of paroxetine with terfenadinom and other drugs that are substrate for the CYP3A4 isoenzyme, does not cause unwanted reactions.

The simultaneous use of paroxetine with MAO inhibitors, may cause the development of tryptophanyl serotoninovogo syndrome evident agitation, anxiety disorders from ZHKT, including diarrhea.

Daily Appointment paroxetine significantly increased the level of protsiklidina plasma. If there are symptoms antiholinergicheskih protsiklidina dose should be reduced.

Interaction paroxetine with warfarin may increase bleeding time when prothrombin time unchanged.

Unlike antidepressants, which inhibit the seizure of norepinephrine, paroxetine inhibits much weaker antihypertensive effect guanetidina.

Dosing and Administration in Adults

Inside, 1 time per day, morning, along with eating - 20 mg. Tablets should be down entirely, not razzhevyvaya, zapivaya water. In poor effect may increase dose to 10 mg / day at intervals of not less than 1 week (maximum dose - 50 mg / day). Older depleted patients, as well as in violation of the functions of the kidneys and liver of the starting dose - 10 mg / day, maximum - 40 mg / day.

Dosing and Administration in pediatric practice

The use of medication in children (under 18) is not recommended, since safety and efficacy of its use in children has not been established.
Pregnancy and lactation

Safety of use in pregnancy has not been studied, so it should not be used during pregnancy and during lactation (breastfeeding), except with the medical point of view of the potential benefits of treatment exceed the possible risks associated with taking the medication. In appointing the drug during lactation is necessary to give up breastfeeding.

Overdosage
Symptoms: increased above-described side effects, as well as vomiting, headache, broadening pupils, fever, changes in blood pressure, involuntary muscle contraction, excitation, anxiety, tachycardia. Patients usually do not develop serious complications, even with the admission of up to 200 mg of paroxetine. Sometimes coma develops and changes in the EEG, it is rarely fatal, with the combined use of paroxetine with psychotropic drugs with alcohol or without it.

Treatment: standard events are used for overdose antidepressants (catharsis through simulated vomiting or washing, the appointment of 20-30 mg of activated charcoal every 4-6 hours during the first days after the overdose). The specific antidote is not known. There is a need for close observation and monitoring of vital functions.

Cautions

The drug should be used with caution with hepatic insufficiency, renal insufficiency, zakrytougolnoy glaucoma, prostate hyperplasia, maniyah, heart disorders, epilepsy, convulsive states, in the presence of risk factors for increased bleeding and predisposing to the disease, in combination with elektroimpulsnoy therapy with oral anticoagulants .

With a sharp lifting may develop symptoms such as dizziness, paresthesia, insomnia, agitation, anxiety, nausea and sweating.

If observed on the background of the treatment increased hepatic enzymes remains a long time, receiving the drug should be discontinued.

Pax does not potentiator effect of alcohol on psychomotor functions, however, patients are encouraged to abstain from alcohol.

It is cognitive or psychomotor retardation violations. Nevertheless, as in the treatment of any psychotropic drugs, patients should be careful when driving a car and work with moving machinery.