Drotaverin

# Drotaverin ## Overview - **Classification**: Selective Phosphodiesterase-4 Inhibitor (PDE4), Antispasmodic Agent. - **Mechanism**: Inhibits PDE4, leading to increased intracellular cAMP in smooth muscle cells. This causes relaxation of smooth muscles, particularly in the gastrointestinal and genitourinary tracts. ## Primary Indications 1. **Smooth Muscle Spasms**: Treatment of spasms associated with biliary colic and cholecystitis. 2. **Renal Colic**: Alleviation of pain due to spasms associated with urolithiasis and kidney colic. 3. **Dysmenorrhea**: Relief of painful uterine spasms during menstruation. ## Adult Dosing ### Standard Dosing **General Smooth Muscle Spasms (Oral)** - **Dose**: **40 mg** to **80 mg** - **Frequency**: Two to three times per day (TID) - **Route**: Oral (Tablet) - **Maximum Daily Dose**: **240 mg** **Acute Severe Spasms (IM/IV)** - **Dose**: **40 mg** to **80 mg** - **Frequency**: Repeat dose if needed, up to 3 times per day. - **Route**: Intramuscular (IM) or slow Intravenous (IV) injection. ### Dose Adjustments - **Renal Impairment**: Drotaverin should be used with caution; no specific dose reduction universally established. - **Hepatic Impairment**: Caution advised, especially in severe impairment; monitor hepatic function closely. - **Elderly Patients**: Generally tolerated at standard adult doses, but initiate at the lower end of the dosing range due to decreased hepatic clearance. ## Pediatric Dosing ### Neonates (0-28 days) - Use is generally **contraindicated** due to lack of safety data and risk of adverse effects. ### Infants (1-12 months) - Use generally **not recommended**. Consult a pediatric specialist. ### Children (1-6 years) - **Dose**: **10 mg** to **20 mg** per dose - **Frequency**: Two to three times per day (TID) - **Maximum**: Do not exceed **120 mg** per day. ### Children (6-12 years) - **Dose**: **20 mg** per dose - **Frequency**: Two to five times per day - **Maximum**: Maximum daily dose is **200 mg**. ### Adolescents (13-18 years) - Dosing mirrors the lower range of the **Adult Dosing**. - **Dose**: **40 mg** per dose - **Maximum**: Do not exceed **240 mg** per day. ## Safety Information ### Contraindications - **Absolute**: Severe hepatic, renal, or cardiac failure (e.g., severe heart low output syndrome). - **Absolute**: Hypersensitivity to drotaverin or the formulation's excipients. - **Absolute**: Children under 1 year (oral use in infants). ### Common Adverse Effects - **Common (1-10%)**: Headache, dizziness, nausea, vomiting. - **Less Common**: Palpitations, hypotension (especially with IV administration). - **Serious but Rare**: Angioedema, severe allergic reactions (anaphylaxis). ### Key Drug Interactions - **Levodopa**: Drotaverin may reduce the anti-parkinsonian effects of Levodopa. **Avoid concurrent use** if possible. - **Other Antispasmodics (e.g., Papaverine)**: Increased risk of adverse effects due to additive effect; use with caution. - **Tricyclic Antidepressants (TCAs)**: Potential for enhanced hypotensive effects when given concomitantly. ## Monitoring & Follow-up - **Before Treatment**: Assess baseline blood pressure, especially if IV route is planned. - **During Treatment**: Monitor heart rate and blood pressure, particularly following parenteral administration. - **Clinical Signs**: Watch for signs of hypersensitivity (rash, swelling) or severe hypotension. ## Clinical Pearls - 💡 **Tip 1**: IV/IM administration should be performed slowly to minimize the risk of transient **hypotension**. - 💡 **Tip 2**: Drotaverin acts directly on smooth muscle and does **not** mask symptoms of acute abdomen like opioids might. - 💡 **Tip 3**: Counsel patients that dizziness may occur; avoid driving or operating machinery until effects are known. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.