Antrenex® - Professional Product Information

Indications

• Pain due to smooth muscle spasm (e.g., GI, biliary, urinary tract)

• Adjunctive relief of peptic ulcer pain

Pharmacology

Dual Mechanism of Action:

1. Antimuscarinic Effect:

   • Blocks acetylcholine at muscarinic receptors → reduces spasms.

2. Direct Musculotropic Effect:

   • Relaxes smooth muscle independent of anticholinergic activity.

Dosage & Administration

• Administration: Oral, whole tablet (do not crush/chew). With or without food.

• Dosing: Individualized; continue as prescribed to prevent symptom rebound.

• Missed Dose: Take ASAP if near scheduled time; never double dose.

Side Effects

Common (Anticholinergic Effects):

Dry mouth (xerostomia) • Constipation • Photophobia • Flushing • Tachycardia
Reduced bronchial secretions • Urinary retention • Blurred vision (loss of accommodation)

CNS Effects: Dizziness, sedation.

Contraindications

• Glaucoma (angle-closure) • Myasthenia gravis • Obstructive GI/Uropathy • Severe UC

Precautions & Warnings

1. CNS Depression:

   • Avoid driving/operating machinery until response known.

2. Alcohol Interaction: ↑ Sedation risk.

3. Special Populations:

   • Pregnancy/Lactation: Use only if benefit > risk.

   • Hepatic/Renal Impairment: Dose adjustment may be needed.

4. Geriatric Patients: ↑ Sensitivity to anticholinergic effects.

Drug Interactions

• CNS Depressants (alcohol, opioids, benzodiazepines): ↑ Sedation.

• Other Anticholinergics: Additive toxicity (e.g., confusion, constipation).

Patient Counseling Points

• Report severe constipation/urinary retention immediately.

• Use sugar-free lozenges for dry mouth.

• Avoid heat exposure (↓ sweating risk).

Overdose Management

Symptoms: Hyperthermia, psychosis, respiratory depression.
Treatment:

1. Gastric lavage + activated charcoal.

2. Physostigmine (for severe anticholinergic delirium).

3. Supportive care (IV fluids, cooling).

Therapeutic Class

Antispasmodic / Anticholinergic

Storage

• Below 25°C; protect from moisture.