LACTOLOGY FOUNDATION

Liquid paraffin (ATC A06AA01) is an emollient laxative used for short‑term relief of constipation; in lactation it is generally considered low to moderate risk, but prolonged oral use is discouraged and safer alternatives are preferred.medpedia.framar+3

Active substance and ATC class

Liquid paraffin (paraffinum liquidum) is a highly refined mineral oil composed of saturated hydrocarbons derived from petroleum. It is classified under ATC code A06AA01 in the group of emollient laxatives, softeners that facilitate defecation by lubricating and softening stool.mims+2

Liquid paraffin is a transparent, colourless, nearly odourless oily liquid, used both as a medicinal laxative and as an emollient in dermatological and cosmetic preparations. Fuel paraffin/kerosene must be clearly distinguished from medicinal liquid paraffin, which is specifically purified for human use.wikidoc+1

Indications in clinical use

Medicinal liquid paraffin is indicated for the short‑term symptomatic treatment of constipation, particularly when straining should be avoided (e.g. anal fissures, haemorrhoids, post‑operative states). It may be used alone or in combination products with osmotic laxatives (e.g. liquid paraffin plus magnesium hydroxide or “milk of magnesia”).e-lactancia+4

It is also used as a bowel‑softening agent in preparation for certain procedures (e.g. endoscopy, radiological examinations) and as an emollient to soften and hydrate dry, pruritic skin in conditions such as eczema or ichthyosis. In routine practice, its role as a laxative is limited to occasional, short‑term use due to safety concerns with chronic administration.hpra+2

Mechanism of action and pharmacodynamics

Orally administered liquid paraffin is minimally absorbed from the gastrointestinal tract and acts locally in the intestinal lumen. It coats the intestinal mucosa and the stool, reducing water reabsorption from faeces and providing a lubricating effect that facilitates passage of softened stool.greenbook.nafdac+3

This dual action—softening and lubrication—reduces the need for straining and eases defecation, typically after a delay of several hours. With prolonged use, interference with intestinal motility has been reported, and the bowel may lose normal peristaltic tone, contributing to dependence on laxatives.medpedia.framar+2

Pharmacokinetics

Liquid paraffin is largely indigestible and only slightly absorbed after oral administration. Small absorbed quantities can accumulate in tissues, including the intestinal wall, where they may trigger foreign‑body granulomatous reactions.meadowsvets+1

Because liquid paraffin remains within the intestinal lumen, it can impair the absorption of fat‑soluble vitamins (A, D, E, K) and possibly other lipophilic nutrients when used inappropriately or for prolonged periods. If aspirated into the respiratory tract, it may cause lipoid pneumonia, a serious complication associated with chronic use or administration to patients with swallowing difficulties.hpra+3

Dosage and administration

Oral liquid paraffin is administered as a syrup or solution, usually once daily. Typical adult doses range from about 10–45 ml per day, often given in the evening but not immediately before going to bed to reduce aspiration risk in the supine position. National product characteristics frequently recommend short treatment duration (e.g. up to one week) for occasional constipation.mims+3

Bulgarian sources recommend 1–2 tablespoons per day, at least two hours after meals and other medications, to limit interference with nutrient and drug absorption. Paediatric use is generally restricted or contraindicated in younger children (often under 2–3 or 6 years, depending on the product) due to higher risks of aspiration and systemic adverse effects.meadowsvets+2

Rectal preparations (paraffin enemas) may be used for constipation, with adult doses around 60–150 ml once daily and lower volumes in children, again limited to short‑term administration. Topical formulations (lotions, ointments) are applied as required to hydrate and soften dry, irritated skin.wikidoc+1

Contraindications and precautions

Liquid paraffin is contraindicated in patients with known hypersensitivity to mineral oil or formulation excipients. It should not be used in individuals with intestinal obstruction, appendicitis, inflammatory bowel disease, or abdominal pain of unknown origin because it may mask symptoms and complicate diagnosis.truemeds+3

Many product characteristics advise against use in children below certain age cut‑offs (commonly under 2–3 years and sometimes under 6 years) due to aspiration risk and limited safety data. It is also discouraged in frail elderly or patients with severe chronic disease or swallowing difficulties, in whom inadvertent inhalation can lead to lipoid pneumonia.medpedia.framar+2

Prolonged continuous use is not recommended in any population because it may suppress normal bowel motility, interfere with micronutrient absorption, and increase the likelihood of local and systemic adverse effects. In patients under regular medical care or with complex comorbidities, several summaries of product characteristics advise that liquid paraffin should only be taken if specifically recommended by a physician.hpra+4

Adverse effects

Gastrointestinal and local effects

Common gastrointestinal adverse reactions include abdominal pain or cramps, nausea, vomiting, diarrhoea, and oily rectal leakage. Leakage of mineral oil past the anal sphincter can cause perianal irritation, pruritus ani, haemorrhoids, and soiling of clothes.truemeds+3

With chronic use, dependence and loss of normal peristalsis may occur, manifesting as constipation rebound when the laxative is withdrawn. The lubricant effect can also impair the absorption of fat‑soluble vitamins and possibly other lipophilic drugs, contributing to subclinical deficiencies in long‑term users.hpra+2

Systemic and respiratory effects

Granulomatous reactions in intestinal tissues and lymph nodes have been reported due to absorption and deposition of small quantities of mineral oil. The most clinically significant potential adverse event is exogenous lipoid pneumonia, resulting from chronic aspiration of liquid paraffin, particularly in elderly, debilitated, or neurologically impaired patients.wikidoc+2

Allergic or hypersensitivity reactions are uncommon but may occur, presenting as rash or other allergic manifestations. In combination preparations containing magnesium hydroxide, additional risks such as central nervous system depression in patients with renal insufficiency may be present.e-lactancia+1

Drug–nutrient and drug–drug interactions

Liquid paraffin can reduce the intestinal absorption of fat‑soluble vitamins A, D, E and K, especially when used in higher doses or chronically. This effect is clinically relevant in patients with marginal vitamin status or in those receiving vitamin supplementation for deficiency states.medpedia.framar+1

Interactions with potassium‑sparing diuretics have been described, with liquid paraffin reported to disturb their therapeutic action, though mechanisms are not fully elucidated. Because of its interference with absorption of lipophilic substances, caution is advisable when other oral medicines requiring reliable uptake are administered close in time to liquid paraffin; separating dosing by at least two hours is often recommended.hpra+1

Use in pregnancy

Clinical data on the use of pure liquid paraffin in pregnancy are limited, and product information sheets provide differing recommendations. Some regulatory documents state that safety in pregnancy has not been firmly established and therefore recommend avoidance or use only if clearly necessary.mims+2

Other clinical resources note long‑standing widespread use of liquid paraffin without apparent major teratogenic consequences, but still advise preference for alternative laxatives with better characterised safety (e.g. lactulose, macrogol/PEG, magnesium hydroxide) for routine management of constipation in pregnant women. In toxicological‑lactological classification, liquid paraffin would typically be placed in a precautionary category for pregnancy where benefit–risk evaluation and short‑term use only are emphasised.e-lactation+3

Use in lactation

Specialised breastfeeding resources consider liquid paraffin in topical preparations and as an oral laxative as presenting a low to moderate level of risk, with important practical restrictions. Some clinical portals state that liquid paraffin is “safe to use during lactation” given the absence of documented serious adverse outcomes despite widespread use. However, e‑lactation specifically advises avoiding mineral‑oil laxatives when possible and favouring safer alternatives such as lactulose, polyethylene glycol, or magnesium hydroxide for breastfeeding mothers.doctoroncall+1

Topical paraffin‑containing creams or ointments should be minimised during breastfeeding and not applied to the breast area or, if necessary, thoroughly removed before the next feed to reduce infant ingestion and nipple aspiration risk. Prolonged oral use is discouraged in lactating women due to potential accumulation, interference with maternal vitamin status, and theoretical concerns about exogenous lipoids reaching the infant via milk or by aspiration during co‑sleeping.e-lactation+1

Within a toxicological‑lactological framework, medicinal liquid paraffin as a laxative in breastfeeding can be classified as:

·        Low risk/compatible for short‑term oral use, with clinical follow‑up and strict attention to dosage and duration.doctoroncall+1

·        Preferably replaced by very‑low‑risk alternatives (lactulose, macrogol, magnesium hydroxide) for routine or repeated treatment of constipation in breastfeeding women.e-lactation

Paediatric use and lactation‑related paediatrics

Liquid paraffin is mainly used as a laxative in paediatric practice for constipation and encopresis, but multiple product monographs advise caution or outright avoidance in infants and very young children. The risk of aspiration and subsequent lipoid pneumonia is higher in infants, especially when doses are administered close to bedtime or to children with swallowing or neurological problems.wikipedia+3

For breastfed infants, direct administration of liquid paraffin laxatives is generally discouraged, and safer agents (e.g. lactulose, macrogol) are preferred. Any inadvertent ingestion via maternal use (e.g. topical application on the breast) should be prevented by avoiding application or thoroughly cleansing the nipple area before feeding.e-lactation

Toxicological concerns

From a toxicological perspective, the main concerns with liquid paraffin are:

·        Chronic aspiration leading to exogenous lipoid pneumonia, characterised by cough, dyspnoea, and radiologic infiltrates.meadowsvets+2

·        Tissue accumulation and granulomatous reactions in the intestinal wall and lymphatic structures after long‑term exposure.wikidoc+1

·        Interference with fat‑soluble vitamin absorption, contributing to deficiencies in susceptible individuals.medpedia.framar+1

Systemic acute toxicity from oral ingestion of medicinal doses is low, but misuse or prolonged dosing increases the risk of serious respiratory and nutritional complications. In lactation toxicology, these issues translate into a preference for shorter courses, lower doses, and alternatives where possible, particularly in mothers and infants with respiratory or swallowing vulnerabilities.meadowsvets+2

Toxicological‑lactological classification summary (A06AA01)

For your specialised database, liquid paraffin (ATC A06AA01) can be summarised as:

·        Pregnancy: Use only if clearly needed; avoid prolonged courses; consider safer laxatives as first‑line.mims+2

·        Lactation (mother): Low to moderate risk; short‑term oral use acceptable with monitoring; avoid chronic use; prefer lactulose, PEG, magnesium hydroxide.doctoroncall+1

·        Lactation (infant exposure): Avoid direct infant administration; prevent topical exposure from breast applications; monitor for respiratory symptoms if exposure suspected.e-lactation+1

·        Overall toxicological profile: Low acute systemic toxicity, but clinically relevant chronic risks—lipoid pneumonia, granulomas, vitamin malabsorption—necessitate strict limitation to short‑term, carefully selected use.hpra+2