Solixa-Xantis

Solixa-Xanthis (Solifenacin) is a medicine used to treat the symptoms of overactive bladder (OAB). OAB is characterized by symptoms such as frequent urination, a strong and sudden urge to urinate (urgency), and urinary incontinence due to urgency.

Solifenacin is an antimuscarinic (anticholinergic) agent that acts by blocking muscarinic receptors in the bladder. This results in relaxation of the detrusor muscle of the bladder, decreasing the frequency and force of bladder contractions and improving the ability to control urination.

Indications Solixa-Xantis

1. Frequent urination: Increased frequency of urination during the day and at night (pollakiuria).
2. Urgency: A strong and sudden urge to urinate that is difficult to control.
3. Urge urinary incontinence: Involuntary loss of urine due to an urgent need to urinate.

Release form

Tablets: Solixa-Xantis is available as tablets for oral use, which typically contain 5 mg and 10 mg of solifenacin succinate.

Pharmacodynamics

1. Muscarinic receptor antagonism: Solifenacin blocks muscarinic acetylcholine receptors in various organs and tissues such as the bladder, resulting in decreased activity of the cholinergic system.
2. Decreased bladder contractions: Blocking muscarinic receptors in the bladder with solifenacin reduces spontaneous bladder contractions and increases bladder capacity, which may help reduce the frequency and force of urination.
3. Improving urinary incontinence symptoms: Using solifenacin can help reduce symptoms of urinary incontinence, such as frequent, involuntary, or feeling the need to go to the toilet frequently.
4. Improving Bladder Function: Blocking muscarinic receptors may also improve bladder function in patients with overactive bladder, helping them to have better control over their urinary functions.
5. Smooth muscle spasm reduction: Solifenacin may also have a spasmolytic effect on the smooth muscles of the bladder, which helps to relax it and reduce spasms.

Pharmacokinetics

1. Absorption:

   • After oral administration, solifenacin is well absorbed from the gastrointestinal tract.
   • The maximum concentration in blood plasma is reached approximately 3-8 hours after administration.
   • Bioavailability is about 90%.

2. Distribution:

   • The volume of distribution of solifenacin is approximately 600 liters.
   • The drug binds to plasma proteins by 98%, mainly to albumin and acidic alpha1-glycoproteins.

3. Metabolism:

   • Solifenacin is extensively metabolized in the liver with the participation of the enzyme CYP3A4.
   • The major metabolites include 4R-hydroxylated and N-glucuronidated compounds.

4. Excretion:

   • The half-life of solifenacin is approximately 45-68 hours.
   • Approximately 70% of the administered dose is excreted in the urine, of which about 11% is excreted as unchanged drug and 18% as the N-glucuronide metabolite.
   • About 23% of the dose is excreted in the feces.

5. Special populations:

   • In elderly patients, as well as in patients with impaired liver or kidney function, the pharmacokinetics of solifenacin may be altered, which may require dosage adjustment.

Dosing and administration

Recommended dosage:

1. Initial dose:

   • It is generally recommended to start with a dosage of 5 mg once daily.

2. Maintenance dose:

   • If necessary and if the drug is well tolerated, the dose can be increased to 10 mg once a day.

Directions for use:

• The tablets are taken orally with a sufficient amount of water.
• Time of administration: Tablets can be taken regardless of food intake.
• Frequency: The drug is taken once a day, preferably at the same time each day to maintain a stable level of the drug in the body.

Special instructions:

• Missed Dose: If you miss a dose, take it as soon as possible. If it is almost time for your next dose, do not take a double dose to make up for the missed dose. Just continue taking it as usual.
• Overdose: In case of overdose, seek medical attention immediately.

Use Solixa-Xantis during pregnancy

The use of Solix-Xantis during pregnancy is not recommended, as there is no convincing data on its safety for the fetus. Here are the main points from the available studies:

1. A pharmacokinetic interaction study of solifenacin with oral contraceptives showed that solifenacin does not affect the pharmacokinetics of ethinyl estradiol and levonorgestrel, which may be relevant for its use in reproductive age. However, this study did not address the safety of solifenacin use during pregnancy itself (Taekema-Roelvink et al., 2005).
2. A study of the efficacy and safety of post-micturition dribbling in women found no significant differences between solifenacin and placebo. The study did not include a specific group of pregnant women, so safety data for solifenacin during pregnancy remain limited (Ablove et al., 2018).

Due to insufficient data on the safety of solifenacin use during pregnancy, it is important to consult a doctor before using it to assess all potential risks to the developing fetus.

Contraindications

1. Hypersensitivity: People with known hypersensitivity or allergic reaction to solifenacin or any other components of the drug should avoid its use.
2. Severe renal impairment: The drug is not recommended for use in patients with severe renal impairment (creatinine clearance <30 ml/min), especially if they are receiving strong CYP3A4 inhibitors (eg, ketoconazole).
3. Severe hepatic impairment: Solifenacin is contraindicated in patients with severe hepatic impairment (Child-Pugh class C).
4. Closed-angle glaucoma: The drug is not recommended for use in patients with uncontrolled closed-angle glaucoma due to the risk of increased intraocular pressure.
5. Myasthenia gravis: Solifenacin may worsen the symptoms of myasthenia gravis and is therefore contraindicated in this condition.
6. Acute urinary retention: The drug is contraindicated in patients with acute urinary retention as it may worsen the condition.
7. Gastrointestinal Obstruction: The drug is contraindicated in patients with gastrointestinal obstruction, including toxic megacolon and paralytic ileus.
8. Severe gastroparesis: The drug should not be used in patients with severe gastroparesis (delayed gastric emptying).

Side effects Solixa-Xantis

1. Very common side effects (more than 10%):

   • Dry mouth.

2. Common side effects (1-10%):

   • Constipation.
   • Nausea.
   • Dyspepsia (indigestion).
   • Abdominal pain.
   • Dry eyes.
   • Blurred vision.
   • Rapid heartbeat (tachycardia).
   • Fatigue.

3. Uncommon side effects (0.1-1%):

   • Urinary tract infections.
   • Difficulty urinating (eg, urinary retention).
   • Urinary retention.
   • Dry skin.
   • Feeling thirsty.
   • Visual disturbances, including blurred vision.
   • Drowsiness.
   • Dizziness.
   • Sinusitis.

4. Rare side effects (0.01-0.1%):

   • Anaphylactic reactions.
   • Allergic reactions such as skin rash or itching.
   • Angioedema.
   • Confusion of consciousness.
   • Hallucinations.
   • Heart rhythm disturbances (eg, prolongation of the QT interval, arrhythmia).

5. Very rare side effects (less than 0.01%):

   • Psychiatric disorders (eg, anxiety, depression).
   • Cramps.
   • Worsening of glaucoma symptoms.

Overdose

1. Anticholinergic effects: Such as dry mouth, constipation, urinary retention, mydriasis (dilated pupils), dry skin and redness, tachycardia, increased heart rate.
2. Central effects: Headache, dizziness, agitation, confusion, hallucinations, drowsiness.
3. Serious complications: Severe overdose may result in seizures, coma, respiratory depression, and cardiovascular complications.

Treatment of overdose

Treatment of solifenacin overdose is usually aimed at relieving symptoms and supporting vital functions:

1. Activated charcoal: Taking activated charcoal may help reduce the absorption of the drug from the gastrointestinal tract if a short period of time has passed since administration.
2. Gastric lavage: May be helpful if large amounts of the drug have been taken recently.
3. Symptomatic therapy: Support of respiratory and cardiovascular functions. This may include intravenous fluids, maintenance of blood pressure, and cardiac monitoring.
4. Antidotes: In severe cases of anticholinergic symptoms, physostigmine may be prescribed under medical supervision.
5. Hospitalization: In severe cases, hospitalization for intensive monitoring and treatment may be required.

Interactions with other drugs

1. CYP3A4 inhibitors: Drugs that inhibit the CYP3A4 enzyme (eg, ketoconazole, itraconazole, ritonavir, clarithromycin) may increase the blood levels of solifenacin, which may increase its side effects.
2. CYP3A4 inducers: Drugs that induce the CYP3A4 enzyme (eg, rifampin, phenytoin, carbamazepine) may decrease the blood concentration of solifenacin, which may reduce its effectiveness.
3. Anticholinergic drugs: Concomitant use with other anticholinergic drugs (eg, atropine, scopolamine, some antidepressants and antipsychotics) may increase anticholinergic side effects such as dry mouth, constipation, blurred vision, and difficulty urinating.
4. Drugs that prolong the QT interval: Co-administration with drugs that prolong the QT interval (eg, class IA and III antiarrhythmic drugs, some antidepressants and antipsychotics) may increase the risk of cardiac arrhythmias.
5. Drugs that alter gastrointestinal motility: Drugs that alter gastrointestinal motility (eg, metoclopramide) may affect the absorption of solifenacin.
6. Antihistamines: Some antihistamines may enhance the anticholinergic effects of solifenacin.
7. Medicines that alter gastric pH: Antacids and other drugs that alter gastric pH may interfere with the absorption of solifenacin.