Usage
Drotaverine is an antispasmodic drug prescribed to relieve smooth muscle spasms. It is primarily used for conditions causing abdominal pain, including:
- Irritable bowel syndrome (IBS)
- Renal colic (kidney stones)
- Biliary colic (gallstones)
- Intestinal colic
- Dysmenorrhea (painful menstruation)
- Uterine spasms during labor
Its pharmacological classification is antispasmodic.
Drotaverine’s mechanism of action involves inhibiting phosphodiesterase-4 (PDE4), an enzyme responsible for breaking down cyclic AMP. Increased levels of cyclic AMP lead to smooth muscle relaxation and reduced spasms.
Alternate Names
Drotaverine is sometimes referred to as Drotaverin. Several brand names exist, including No-Spa, Spasmonal, and Duspatalin.
How It Works
Pharmacodynamics: Drotaverine directly targets smooth muscle cells, causing relaxation and relieving spasms. Unlike other antispasmodics, it lacks anticholinergic effects, minimizing side effects like dry mouth and blurred vision.
Pharmacokinetics:
- Absorption: Drotaverine is well-absorbed after oral administration.
- Metabolism: It undergoes hepatic metabolism, likely involving CYP enzymes.
- Elimination: Primarily excreted via the kidneys.
Mode of Action: Drotaverine selectively inhibits PDE4, leading to increased intracellular cyclic AMP and decreased intracellular calcium levels. This process results in smooth muscle relaxation. It doesn’t directly affect receptors or neurotransmitters but acts on intracellular mechanisms.
Elimination Pathways: Drotaverine is predominantly eliminated through renal excretion, with a minor contribution from hepatic metabolism.
Dosage
Standard Dosage
Adults: 40-80 mg, three times a day. The dosage may vary based on individual response and the condition being treated.
Children:
- 1-6 years: 20 mg, three to four times daily.
- Over 6 years: 40 mg, one to two times daily.
Special Cases:
- Elderly Patients: Dose adjustment may be necessary based on renal and hepatic function.
- Patients with Renal Impairment: Dosage adjustments are crucial in severe impairment. Monitor closely.
- Patients with Hepatic Dysfunction: Adjustments are advised, especially in severe dysfunction. Close monitoring is necessary.
- Patients with Comorbid Conditions: Careful consideration and dosage adjustments are necessary based on other medical conditions, such as cardiovascular disease or diabetes.
Clinical Use Cases
Drotaverine’s use in specific clinical settings, like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations (e.g., status epilepticus, cardiac arrest), is not standard practice and limited. Consult other resources or guidelines for specific recommendations.
Dosage Adjustments
Adjustments are necessary based on individual response, hepatic/renal function, other medical conditions, and concomitant medications. Genetic polymorphisms affecting drug metabolism may also require dosage modification.
Side Effects
Common Side Effects
- Nausea
- Vomiting
- Dry mouth
- Dizziness
- Headache
- Constipation
- Insomnia
- Allergic skin reactions
Rare but Serious Side Effects
- Hypotension (low blood pressure)
- Allergic reactions (including angioedema)
- Cardiac arrhythmias
Long-Term Effects
Long-term effects are rare when used as directed. However, regular monitoring may be required for liver function in long-term use, especially for pre-existing liver disease.
Adverse Drug Reactions (ADR)
Severe allergic reactions like angioedema or anaphylaxis require immediate medical attention. Significant hypotension or cardiac arrhythmias also necessitate prompt intervention.
Contraindications
- Hypersensitivity to drotaverine
- Severe hepatic, renal, or cardiac dysfunction
- Porphyria
- Neonates
- Children under 1 year (safety not established)
Drug Interactions
- Levodopa: Drotaverine may reduce its effectiveness.
- Alcohol: Increases risk of dizziness.
- Quinidine and procainamide: Potentiates their hypotensive effects.
- Tricyclic antidepressants: Potentiates their hypotensive effects.
- Morphine: Reduces its spasmogenic activity.
- Hormonal contraceptives: May reduce their effectiveness.
Pregnancy and Breastfeeding
Drotaverine use should generally be avoided during pregnancy and lactation unless the potential benefits outweigh the risks. While animal studies have not shown teratogenic effects, there’s insufficient human data to confirm safety. It’s excreted in breast milk, so breastfeeding mothers should avoid its use.
Drug Profile Summary
- Mechanism of Action: Inhibits PDE4, leading to smooth muscle relaxation.
- Side Effects: Nausea, vomiting, dry mouth, dizziness, headache, constipation, allergic reactions. Rarely: hypotension, cardiac arrhythmias.
- Contraindications: Hypersensitivity, severe hepatic/renal/cardiac disease, porphyria, neonates.
- Drug Interactions: Levodopa, alcohol, quinidine, procainamide, tricyclic antidepressants.
- Pregnancy & Breastfeeding: Avoid unless potential benefits outweigh risks.
- Dosage: Adults: 40-80 mg TID. Children: Dosage varies by age. Adjustments necessary for special populations.
- Monitoring Parameters: Liver function (long-term use), blood pressure.
Popular Combinations
While Drotaverine is sometimes combined with analgesics for enhanced pain relief, no specific combinations are universally recommended. Clinical judgment based on the patient’s condition and the specific pain cause is essential.
Precautions
- Pre-existing heart, liver, or kidney disease warrants caution.
- Avoid in pregnancy and breastfeeding, unless absolutely necessary.
- Dosage adjustment may be necessary in elderly patients.
- Caution is advised when driving or operating machinery due to potential dizziness.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Drotaverine?
A: Adults: 40-80 mg three times daily. Children: 1-6 years: 20 mg three to four times daily; over 6 years: 40 mg one to two times daily.
Q2: How does Drotaverine work?
A: It inhibits PDE4, leading to smooth muscle relaxation.
Q3: Is Drotaverine safe during pregnancy?
A: It should be avoided unless the benefits clearly outweigh the risks.
Q4: What are the common side effects?
A: Nausea, vomiting, dry mouth, dizziness, and headache.
Q5: Can I take Drotaverine with alcohol?
A: No, alcohol may intensify dizziness.
Q6: What conditions does Drotaverine treat?
A: Smooth muscle spasms in various conditions like IBS, renal colic, biliary colic, and dysmenorrhea.
Q7: Are there any drug interactions I should be aware of?
A: Yes, it interacts with levodopa, alcohol, some antihypertensives, and certain other drugs.
Q8: What should I do if I miss a dose?
A: Take the missed dose as soon as you remember unless it is almost time for the next scheduled dose.
Q9: Can Drotaverine be used in children?
A: Yes, but at a reduced dose based on age and weight.
