Tizadin 2mg Tablet | 1 Strip

✔️ Pharmacology

Class: Centrally acting skeletal muscle relaxant

Mechanism of Action:

Acts at the spinal cord level by stimulating presynaptic alpha-2 adrenergic receptors.

Inhibits the release of excitatory amino acids that activate NMDA receptors.

Suppresses polysynaptic transmission in spinal interneurons → reduces excessive muscle tone.

Effects:

Relieves spasms, clonus, and resistance to passive movements.

May improve voluntary strength.

Exerts mild central analgesic activity.

Pharmacodynamics: Efficacy and side effects correlate with plasma concentration levels.

✔️ Use in Special Populations

Pregnancy: Limited human data; use only if the benefit > risk. Animal studies show fetal harm at high doses.

Lactation: Avoid—no human data; excreted in animal milk.

Elderly: Increased sensitivity; titrate carefully.

Children (<18 yrs): Not recommended.

✔️ Side Effects:

Very Common: Somnolence, dizziness, fatigue, dry mouth, GI disturbances, muscular weakness.

Common: Nausea, hypotension, insomnia, abnormal liver enzymes.

Uncommon: Bradycardia.

Rare/Severe: Hallucinations, hepatitis, hypersensitivity (rash, angioedema, anaphylaxis).

✔️ Dosage & Administration

⚠️ Tizanidine has a narrow therapeutic index → dosing must be individualized.

Painful muscle spasms (acute):

• 2–4 mg, three times daily.
• Severe cases: an extra dose at night (to minimize sedation).

Spasticity (neurological origin):

• Start: 6 mg/day in 3 divided doses.
• Titrate by 2–4 mg every 3–7 days.
• Optimal: 12–24 mg/day in 3–4 divided doses.
• Max: 36 mg/day.

Elderly (≥65 yrs): Start at the lowest dose; increase cautiously.

Renal impairment (<25 mL/min): Start 2 mg once daily; titrate slowly.

Hepatic impairment: Contraindicated in severe cases; use cautiously with moderate impairment.

Pediatrics (<18 yrs): Not recommended.

Discontinuation: Taper gradually to avoid rebound hypertension and tachycardia.

✔️ Contraindications

Hypersensitivity to tizanidine.

Severe hepatic impairment.

Concomitant use with strong CYP1A2 inhibitors (fluvoxamine, ciprofloxacin).

✔️ Drug Interactions

Strong CYP1A2 inhibitors (fluvoxamine, ciprofloxacin): Contraindicated → massive increase in plasma levels, risk of hypotension, QT prolongation.

Other CYP1A2 inhibitors (amiodarone, cimetidine, fluoroquinolones, oral contraceptives, ticlopidine, rofecoxib): Not recommended.

Rifampicin: ↓ plasma levels by ~50% → may reduce efficacy. Avoid long-term use.

Cigarette smoking (>10/day): ↓ exposure by ~30% → may require higher doses.

Alcohol: Increases CNS depression, hypotension, sedation → avoid.

Other CNS depressants (benzodiazepines, baclofen, antihistamines, sedatives): Potentiation of sedation.

Antihypertensives: Risk of hypotension, bradycardia, rebound hypertension on withdrawal.

QT-prolonging drugs (cisapride, amitriptyline, azithromycin): Use with caution.

✔️ Precautions & Warnings

Hypotension risk → monitor BP, especially with antihypertensives or CYP1A2 inhibitors.

Hepatic monitoring → check LFTs monthly for first 4 months if ≥12 mg/day. Discontinue if SGPT/SGOT >3× ULN.

Renal impairment: Start at low dose (2 mg daily).

Withdrawal syndrome: Taper dose slowly to prevent rebound hypertension/tachycardia → risk of stroke.

Driving/Operating machinery: May cause drowsiness, dizziness, and sedation.

Hypersensitivity reactions (including anaphylaxis) may occur; discontinue immediately if symptoms appear.

✔️ Storage:

Store below 30°C, in a dry place, protected from light.

Keep out of reach of children.