Yibeian Drotaverine Hydrochloride Tablets

1. Indications and Usage
Pain Relief: Treatment of various types of colic, including gastrointestinal, biliary, renal, and gynecological pain.
Obstetric and Gynecological: Used for dysmenorrhea and threatened abortion with uterine spasm.
Urological: Relieves spasms associated with urinary tract conditions.
2. Dosage and Administration
Adults: The usual dosage is 40 mg to 80 mg (1 to 2 tablets) per dose, taken 2 to 3 times daily.
Children:
Ages 6-12: 20 mg to 40 mg daily, divided into 2 doses.
Ages 12-18: 40 mg to 80 mg daily, divided into 2 to 4 doses.
Administration: The tablets should be taken orally with water.
3. Mechanism of Action
PDE4 Inhibition: Drotaverine inhibits phosphodiesterase type 4, leading to an accumulation of cyclic adenosine monophosphate (cAMP) in cells.
Smooth Muscle Relaxation: The increased cAMP levels cause dephosphorylation of myosin light chains, resulting in relaxation of smooth muscles in the gastrointestinal, biliary, urinary, and gynecological tracts.
4. Safety and Warnings
Contraindications: Contraindicated in patients with severe hepatic, renal, or cardiac failure (including heart failure), and those with hypersensitivity to drotaverine.
Special Populations: Use with caution in pregnant or breastfeeding women, and in elderly patients with severe cardiovascular disease.
Cardiovascular Effects: The drug may cause mild hypotension; caution is advised in patients with low blood pressure.
5. Adverse Reactions and Clinical Research
Common Adverse Reactions: Dizziness, headache, tachycardia, palpitations, and mild gastrointestinal discomfort.
Rare Adverse Reactions: Allergic reactions, including pruritus, urticaria, and rash.
Overdose: Symptoms may include severe hypotension, cardiac arrest, and respiratory depression.
6. Drug Interactions
Anticholinergics: Concomitant use with anticholinergic agents may enhance the antispasmodic effect.
Caffeine: Caffeine may potentiate the antispasmodic action of drotaverine.
Cardiac Drugs: Caution is advised when used with antiarrhythmic drugs (e.g., quinidine) due to potential additive effects on cardiac conduction.
7. Pharmaceutical Information
Active Ingredient: Drotaverine Hydrochloride.
Strength: Tablets typically contain 40 mg of drotaverine hydrochloride.
Chemical Formula: C24H30N2O6·2HCl (Molecular weight: 513.44).
Storage: Store in a dry place, protected from light, at temperatures below 25°C.