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This ATC class contains the single active substance drotaverine, a papaverine derivative and musculotropic antispasmodic used for smooth muscle spasms of the gastrointestinal, biliary, urinary and genital tract. Data on breastfeeding are limited; most reference sources currently recommend caution or avoidance in lactation, especially in newborns and preterm infants, due to lack of clinical experience rather than demonstrated toxicity.medpedia.framar+5

Active substances and ATC context

Drotaverine (also spelled drotaverin) is classified under ATC code A03AD02 within the group “Papaverine and derivatives” (A03AD) in the class of drugs for functional gastrointestinal disorders. It is structurally related to papaverine (benzylisoquinoline derivative) and exerts a direct, non‑anticholinergic spasmolytic effect on smooth muscle.atcddd.fhi+4

These medicines are indicated mainly for functional gastrointestinal disorders with smooth muscle spasm, biliary and urinary tract colic, gynecologic spasm pain such as dysmenorrhea, and tension‑type headache. Injectable forms are sometimes used as adjuncts in obstetrics to facilitate cervical dilatation and relieve labour‑related spasm pain, but this is off‑label in some countries.mims+4

Mechanism of action and pharmacodynamics

Drotaverine is a musculotropic antispasmodic that selectively inhibits phosphodiesterase type 4 (PDE4) in smooth muscle cells, leading to increased intracellular cyclic AMP and subsequent relaxation of gastrointestinal, biliary, urinary and uterine smooth muscle. Unlike anticholinergics, it does not have significant effects on autonomic ganglia or muscarinic receptors, so typical anticholinergic adverse effects are not prominent.drugbank+3

By relieving smooth muscle spasm, drotaverine improves luminal flow (for example in biliary or ureteral colic) and reduces ischemic pain due to vasoconstriction or spasticity. Its lack of significant cardiac conduction or blood‑pressure effects at therapeutic doses makes it suitable for some patients with coronary insufficiency, although caution remains advisable in severe cardiac disease.carehospitals+3

Pharmacokinetics relevant to lactation

After oral administration, drotaverine is rapidly absorbed, undergoes extensive first‑pass metabolism, and is highly protein‑bound; it is metabolised hepatically and excreted mainly in urine and bile as metabolites. The elimination half‑life has been reported in the range of several hours, which suggests that some exposure of a breastfed infant could occur, but no robust human milk concentration data are available.ncbi.nlm.nih+2

High protein binding and extensive metabolism generally limit transfer into breast milk, but in the absence of measured milk/plasma ratios, the degree of infant exposure remains uncertain. No published clinical series have quantified drotaverine in breastfed infants or reported pharmacokinetic parameters specific to the neonatal period.lacted+2

Therapeutic indications and dosing

Drotaverine is used for symptomatic treatment of:

• Smooth muscle spasms of the gastrointestinal tract: gastric and duodenal ulcer disease, gastritis, intestinal colic, irritable bowel syndrome with spastic constipation.searlecompany+2
• Biliary tract spasm: cholelithiasis, cholangiolithiasis, cholecystitis, biliary dyskinesia and associated pain.pacehospital+1
• Renal and urinary tract spasm: nephrolithiasis, ureterolithiasis, cystitis and vesical tenesmus.searlecompany+1
• Gynecologic indications: dysmenorrhea and uterine spasm; adjunctive use for cervical dilatation during labour in some protocols.wikipedia+2
• Tension‑type headache and certain peripheral vasomotor disorders associated with smooth muscle spasm.pacehospital+1

Typical adult oral dosing is 40–80 mg three times daily, corresponding to a daily dose of approximately 120–240 mg in divided doses. Parenteral administration (e.g. 2–4 ml intramuscularly one to three times daily) is reserved for acute spastic pain when oral intake is not feasible.medpedia.framar+3

Contraindications and precautions

Drotaverine is contraindicated in patients with hypersensitivity to the drug or any component of the formulation. It should not be used in patients with severe hepatic, renal or cardiac insufficiency, and many national summaries of product characteristics advise against use in children under one year of age due to limited safety data.mims+2

Caution is necessary in patients with hypotension or pre‑existing conduction disturbances, as rare cases of atrioventricular block and cardiac arrest have been described in overdose. Concomitant administration with levodopa can reduce the antiparkinsonian efficacy of levodopa and may worsen tremor and rigidity, so this combination is generally discouraged.wikipedia+3

Adverse effects and toxicity

Commonly reported adverse effects include nausea, constipation, headache, dizziness, and insomnia, as well as palpitations and arterial hypotension in sensitive individuals. Allergic reactions such as rash, urticaria and pruritus can occur but are usually rare.medpedia.framar+3

Drotaverine has a relatively wide therapeutic index, but significant overdose may result in serious cardiovascular toxicity, including atrioventricular block, severe arrhythmias, marked hypotension and cardiac arrest, and may also depress respiratory function. Management of overdose is supportive, focusing on cardiovascular monitoring, treatment of arrhythmias, haemodynamic support and respiratory assistance as needed, because there is no specific antidote.alfa-chemistry+2

Use in pregnancy

Drotaverine is widely used in some countries during pregnancy for uterine spasm and threatened miscarriage, but controlled data are limited, and regulatory documents often recommend caution. Available information does not indicate a consistent signal for teratogenicity in humans, but absence of evidence is not equivalent to proof of safety, and decisions should be individualised and based on a clear clinical indication.ihan+3

Many product characteristics state that use in pregnancy should be restricted to situations where the expected maternal benefit outweighs any potential risk to the fetus, particularly in the first trimester.swissmedic+1

Lactation safety data

The LactMed database describes drotaverine as a drug with insufficient data in breastfeeding, advising that it should be used with caution, especially when nursing a newborn or preterm infant. Several national monographs and regulatory assessments similarly state that, due to lack of adequate human data, use during breastfeeding is not recommended or should be avoided.ncbi.nlm.nih+2

No published clinical trials or observational cohorts have specifically evaluated infant outcomes after maternal drotaverine therapy during lactation, and no milk concentration data were identified in the current literature. In the absence of direct measurements, risk assessment must rely on pharmacokinetic considerations, isolated case reports and extrapolation from related papaverine derivatives, which is inherently imprecise.lacted+2

Expected infant exposure and theoretical risks

Given its high protein binding, extensive hepatic metabolism and moderate half‑life, transfer of drotaverine into breast milk is likely limited, but measurable exposure cannot be excluded, especially with repeated high‑dose parenteral administration. Theoretical risks for the breastfed infant would include excessive smooth muscle relaxation (e.g. gastrointestinal hypomotility), hypotension, sedation or paradoxical irritability, and potential interference with cardiovascular conduction in predisposed infants.carehospitals+4

These risks are probably very low with short‑term, low‑dose oral therapy in healthy term infants, but may be clinically relevant in preterm neonates, infants with underlying cardiac or respiratory disease, or in situations of maternal polypharmacy. In addition, the lack of long‑term neurodevelopmental follow‑up after exposure to drotaverine during lactation represents an important knowledge gap for risk–benefit evaluation.swissmedic+2

Practical lactation recommendations

Authoritative sources currently advise either to avoid drotaverine during breastfeeding or to use it with particular caution, prioritising alternatives with better‑established lactation safety profiles whenever clinically feasible. If treatment is considered essential in a breastfeeding woman:ncbi.nlm.nih+2

• Prefer short‑term, lowest‑effective dose regimens, and avoid prolonged or high‑dose parenteral therapy.searlecompany+1
• Avoid use in mothers of preterm or medically unstable infants; consider alternative antispasmodics in this setting.lacted+1
• Monitor the breastfed infant for signs of poor feeding, unusual somnolence, hypotonia, gastrointestinal disturbances or colour changes suggestive of hypotension or hypoperfusion.carehospitals+1
• Where dosing is predictable, some experts suggest timing breastfeeding immediately before maternal dosing to minimise peak milk levels, although this is theoretical due to absent PK data.ncbi.nlm.nih+1

In situations where repeated doses are required for several days and the infant is particularly vulnerable (e.g. premature, cardiac disease), temporary partial supplementation or, in rare cases, temporary interruption of breastfeeding may be considered on a case‑by‑case basis after specialist consultation.lacted+1

Alternatives during breastfeeding

For functional gastrointestinal and biliary colic in breastfeeding women, alternative agents with more established lactation safety include:

• Antispasmodics with better lactation data (depending on national availability), such as some anticholinergic agents used at low dose, while monitoring for typical anticholinergic effects in the infant.ihan+1
• Simple analgesics like paracetamol and ibuprofen, which are considered compatible with breastfeeding and may suffice for mild to moderate pain.ihan+1

Choice of alternative should be aligned with local guidelines and individual comorbidities, and where uncertainty exists, consultation of updated lactation databases (e.g. LactMed, e‑lactancia, national teratology information services) is strongly recommended.gifa+2